Ladies and gentlemen, please give a warm welcome to the Director of Cooper Hewitt, Smithsonian Design Museum, Caroline Bowman. For creation, just a welcome to Cooper Hewitt's National Design Off. Tonight's festivities, I am delighted to present the 13th Secretary of the Smithsonian Institution, David Scorton. David served as President of Cornell University for nine years. He is the first medical doctor to lead the Smithsonian, and he is an avid amateur musician. I am thrilled David is here tonight to help us celebrate our winners. Welcome, David. Thanks, Caroline, and welcome everyone. This is going to be a great evening. Do you agree? Yeah. All right, it's going to be wonderful. I want to thank you for coming. I want to take the first chance to congratulate the awardees. I want to ask you for just a moment to join me in recognizing and thanking Caroline Bowman and the staff of the Cooper Hewitt, one of the nation's treasures. Caroline, and I want to thank those of you who, through your generosity and thoughtfulness, helped to make this fabulous institution what it is.  It's a chance for you to get some wine poured in your glass and meet the person next to you. But I want to share just one serious thought with you. Stick with me on this, and then I promise I'll get out of your way, and you can enjoy dinner. So I'm a physician, as Caroline mentioned, and a scientist. And our country focuses on STEM. We want our kids to study STEM. We want our schools to teach STEM. We want to make sure that we're advancing in the world of science, technology, engineering, and mathematics. And I've spent my whole career in those fields. But we all know that our thorniest problems here and around the world are not going to be solved by science alone. And unfortunately, many of our communities and our country is systematically sort of disinvesting in the arts and the humanities. And I've been concerned about this for some years and talking about it. And I've been looking for something to hold up as an example of how we can bring all these fields together and remind people of all the things it is that we value in our lives. And I found it the first time I visited Cooper-Hewitt. Because design defies those easy categorizations. Is it art? Of course. Is it science? You bet. Is it social science? Psychology? Definitely. So design in a word captures many things, many, many things that we value. And I'm thrilled to be a part of the Smithsonian. I've been here 15 weeks, asked me anything. I can tell you anything about it. But I'm thrilled to be here. And I'm really thrilled to have a tiny part in these proceedings tonight. Because I think that what we are doing, what you are doing, and what we will do in the future, is to utilize design as a way not only to make our lives better and lives around the world, but to remind us all of what we value. So thanks for listening. Have a fabulous evening and enjoy. Thank you, David, for those thoughtful words right on. I join you in expressing my sincere gratitude to First Lady Michelle Obama as honorary patron of the National Design Awards. She has been an enthusiastic and effective advocate for design and for Cooper Hewitt these past six years. What a night. What a year. I am truly overjoyed to see everyone here tonight. You are helping make Cooper Hewitt history. Just 10 months ago, we reopened our doors after a once-in-a-lifetime renovation. And I am still electrified by what we achieved. A totally transformed museum dedicated to educating, inspiring, and empowering people through design. The one-of-a-kind Cooper Hewitt team and 13 brilliant design firms renewed Cooper Hewitt inside and out. And I'm very happy that some of those stellar designers and partners are here with us tonight. Jake Barton, Liz Diller, Richard Gluckman, Rick Scafidio, and Bob Zirkel. I am very excited now to share some excellent news that you are the first to hear about. Cooper Hewitt has just been awarded lead silver certification for the museum's renovation project. This is quite an achievement which this audience understands. This mammoth renovation would not have been possible without the unwavering support of our Board of Trustees and the Smithsonian, as well as the generosity of New York City, Bloomberg Philanthropies, Target, and countless individual, foundation, and corporate friends. I'm incredibly proud of what we've accomplished. Hundreds of thousands of visitors have flocked to Cooper Hewitt since our reopening. They love how we have reinvented the museum experience. With our interactive pen in hand, visitors explore Cooper Hewitt's outstanding collection at our high-definition touchscreen table. And in turn, they are learning about design in ways that were never possible before. Since we launched the pen, our visitors have collected close to 2 million design objects to build their own design collections. We're all about accessibility and interactivity. Visiting Cooper Hewitt today offers a social and playful experience. Among the many positive results we've seen is a huge jump in our social media metrics. So hope you don't mind if I pause here for a second and take a selfie for the Cooper Hewitt social media channels. Thanks, Vassa. See if we can beat Ellen Generes' world record for her Oscars tweet. Fantastic. Thanks so much. And here's the address to share. This is the 10th year of National Design Week, which kicked off last weekend with the Target Family Design Festival in our beautifully reimagined Arthur Ross Terrace and Garden. Believe it or not, we welcomed over 7,000 visitors who enjoyed dozens of workshops and activities inspired by this year's winners. 2009 National Design Award winner Walter Hood, working in collaboration with Raft Landscape Architecture and Diller Scafidio and Renfro, translated the garden's historic origins into a stunning contemporary landscape for all of us to enjoy free of charge. Many of our award winners and Tim Gunn were on hand for Tuesday's Teen Design Fair to mentor over 300 future designers. The selfie theme continues. Tuesday evening, we held our sold out winners panel. And Wednesday, design innovators and thought leaders came together for our business of design breakfast. This fall, we will continue our longstanding tradition of celebrating the awards in our nation's capital with our Target Design Summit for DC high school students. I want to thank our winners for their enthusiastic participation all week long, and our Gala leadership, who helped us create this spectacular event. Special thanks as well to David Stark and his design team for making the space so festive using our design in the classroom kits. If you haven't already, please check out your centerpieces. These kits in paper bags beautifully designed by Todd Olden are used by children who participate in our groundbreaking design in the classroom program, which I will share more details about later tonight. This is the only awards program in the country to celebrate the full range of design disciplines. Huge thanks to Design Within Reach, Facebook, and Amazefit for their commitment to and support of Cooper Hewitt. Thank you to Adobe for the online design awards gallery and to Corning Museum of Glass for our stunning trophies. Finally, a very, very special thank you to Target. The Target and Cooper Hewitt teams have worked hand in hand for well over a decade to deliver our shared passion for design to the broadest and most diverse audience possible. Since 1946, Target has generously given 5% of its profit to local communities. Today, that equals more than $4 million a week, and Target has now reached its goal in investing $1 billion for education by the end of 2015. So thank you, Target. I'll be back later this evening to begin our awards ceremony, Bon Appétit.


Even just a single extra serving of fruits and vegetables per day is associated with lower bone fracture risk. Why? Well osteoporotic fracture risk is associated with higher levels of inflammation in your blood, for example C-reactive protein, and specifically a more pro-inflammatory diet. Those eating higher on the dietary inflammatory index have about 30% greater risk of osteoporosis and fracture than those eating more anti-inflammatory diets. And a higher intake of fruits and vegetables decreases inflammation. So that's one possible reason. Free radicals may also play a role in eating away at your bones, suggesting that pro-oxidant stress may contribute to osteoporosis. Both the total antioxidant power and capacity of people's blood streams and diets are significantly lower in those with osteoporosis. And how do we squash free radicals and improve antioxidant status with fruits and vegetables? For example, consumption of vitamin C-rich foods is associated with lower risk of hip fracture, osteoporosis, and bone loss. Every additional increase of 50 milligrams of dietary vitamin C a day, which is about the equivalent of one orange, may lower the risk of hip fracture by 5%. The third way fruits and vegetables may help our bones are through acid-based balance. As we grow older, there's a slight drop in the pH of our blood as our blood becomes more acidic with age. This is thought to be due to the waning ability of our kidneys to excrete excess acid. In vitreous studies, suggests a drop in pH may lead to activation of the cells that break down bone and an inhibition of cells that build bone back up. So how about eating alkaline-forming foods? The most acid-forming foods are meat and cheese, especially fish, and the most alkaline or base-forming foods are fruits and vegetables. This may help explain why, if you experimentally remove fruits and vegetables from people's diets, a mark of bone formation significantly drops, and a mark of bone loss shoots up. And vice versa when you add fruits and vegetables back into their daily diets. The greater the estimated ratio between acid-forming foods and alkaline-forming foods, the greater the risk of hip fracture. Supporting the rationality, less acidic diets, but this was based on observational data to prove cause and effect, two-year, double-blind, randomized controlled trials were performed, in which the three added servings of fruits and vegetables or the equivalent of six extra servings failed to have an effect. But randomized people did the equivalent of nine daily servings of fruits and vegetables worth of an alkaline-forming compound, and you do see a significant increase in bone volume and density in the spine, hip, and throughout the whole body. Are there any fruits and vegetables that are particularly good? That's the question. I'll address next.


In a previous video regarding injuries in the martial arts, I talked about recovering from foot surgery and how I coped with day-to-day challenges. In that video, I mentioned that I used the I Walk Free Knee Crutch. Now, I've had a lot of people ask me about the crutch, how it worked, how I liked it. Many people didn't even know it existed. I use it for six to eight hours a day, every day for six weeks. Everywhere I went, people were surprised to see it and had no idea what it even was. So, I thought I would take the opportunity to do a little bit of an in-depth review on it. This is just an earnest review for my own personal experience. This is not sponsored or paid in any way, so I'm going to tell you everything I liked about it and what I think can be improved and also who I think can benefit from it. I also have listed it below in the description, so if you are interested in picking one up, I highly recommend checking it out. So really quick to recap is back in 2015, I had a torn Achilles tendon in my left foot. The problem with that is I am very active in my work. I'm a video producer by trade, so I'm always doing studio work. I'm always on the field with cameras. I also teach part-time. There was no way I could afford to not work. And I can't run videos. I couldn't do any of this work on crutches. So I kind of panicked a little bit. I'm like, how am I going to do this? I have to have the surgery, but I cannot stop for three months. So I started to do a little bit of research. My first thought was, okay, well, they've got those wheelie scooters that people kneel on. Okay, that's an option. I looked at a few of them. They seemed pretty good, but there were still a few problems with that. One problem was, at the time, I lived in the second floor apartment. Wheels on stairs, those wheelie cars just don't work with stairs, and there were no elevators.  That's great, but that left me tied up. I needed my hands free. If I was going to run a studio camera, you know, I run a camera crane, a jib, and you need two hands with that, and you need to be able to stand independently. And the scooters, you can't really turn without guiding and steering it. So I thought that was a good option, but it wasn't going to fit my needs because it didn't fulfill all the challenges. So I started thinking about, could I build something? Could I construct something? Thankfully, I had a little bit of time before the surgery to do some research, and I considered actually building the crutch of my own. So before I started looking at materials, I'm like, well, let me just take another look, see if there's something out there. And I did a random search on Amazon for knee crutch, and I found this. So I looked at it, did a lot of research, watched a bunch of videos. They have a whole set of videos online if people try it out for the first time. My first initial thoughts when I got it, first, of course, it doesn't come assembled. You have to put it together. And it's not too bad. The assembly is fairly simple, although the instructions aren't the clearest. So it might take you a few attempts. You might end up putting some rods in place and realizing, ah, I shouldn't have done that first.  Overall, it should probably take you about 30 minutes. Once you have it all together, you need to do a fitting and adjustment. This is a great tool, but if you're off balance with it, if it's not set to the right height, you will shortly start to feel a lot of hip pain in your other leg. So what they recommend is, and they have a whole series of videos on their website as well, and also the instructions, how to adjust it for the right height, because you want to be at the right level. So the last thing you want to do is be up, down, up, down. It's going to be very jarring on your joints, and it's not going to feel good after a while. So walk around with it for a while. It's going to feel weird at first. It's a little bit mentally scary, because when you first take your first steps on it, you're depending on another object. It's kind of like crutches. You got to lean on them, but it's weird doing it without your hands. So it's actually recommended that you just, there's a nice handle right here. Easy to grab. So when you're kneeling on it, you just kind of walk with it. Definitely when you first start out, use that. Get used to it. And I would say maybe after an hour or two hours of really walking with it, it starts to become second nature. Now, when you're practicing on this, practice stairs. That was one thing that excited me when I saw this. I saw tons of pictures and videos of people going up and down stairs. Be careful. You're not going to go flying up and down flights. Make sure, since your hands are free, make sure you hold onto your railing if there are any. Go slowly. You will be able to use stairs on this. It's actually pretty easy, but you still have to be careful. It was a total game changer. I had the surgery, came home. I was using it that night. And I'm telling you right now, if it's something you're going to have ahead of time that you know you've got surgery and you plan for it, get this built, get used to it ahead of time because the day of you're not going to feel like putting it together. Have it ready. I still had to take it easy and be careful, but this made all the difference in my day to day activity. I could use stairs. I was able to go on video shoots, carry gear up and down stairs. I was able to run the camera. Everything I was able to do beforehand, I was pretty much able to do on this. Even teach classes. It even got to the point where teaching class, I was able to throw kicks with it. I really shouldn't have done that. But with the kids' graduation classes, I was able to do the ceremonial kicks just by balancing on this alone. As far as taking this on and off, it's actually a pretty good build. They have built-in quick release straps right here. You just kind of pop them on and off. That easy. I would say that with these straps, it takes about 30 seconds more or less to put the device on and it takes about five to take it off. Now it's really good that it's so easy to take on and off because you're going to be doing it a lot. That's the one downfall I had with this is that you really can't sit down with it. It is too cumbersome. I tried and with the days I had some schedules, I was up and down, up and down. Again, I would be in the studio doing work. I'd be teaching class. I'd be going back and forth, getting in and out of the car. Thankfully it was on my left foot, so I was still able to drive with my right foot. But I was taking this thing on and off every day, one to two dozen times. So that gets a little tedious. But thankfully it's a quick release system. But you're not really able to sit with this. It's too bulky. It's too cumbersome. Plus you've got the still part that will be sticking out.  So now let's get to the padding part and the comfort level of this. It's got a built-in knee pad right here. It's pretty good. It's a pretty durable pad. As you can see, this had a lot of use and it's taken some abuse, but it held up. The only thing is after a while, this padding gets compressed. And especially if you're using it every day like I did, I used it for six weeks nonstop. So at the end of those six weeks, the padding did start to feel a little compressed and hard. It's pretty easy fixed. Just honestly, if you feel it's getting too compressed, put a towel, something like that. It's easy to put other padding there. Although I do think that they should have made this a little bit more, maybe replaceable. Maybe it's like you could get a couple of replacement pads. It would have been nice to put in there or additional pads. That's my only real complaint is that after a while, it does get a little hard. Don't throw those crutches away. I would hold onto them because I actually found that they came in handy in conjunction with this many, many, many times.  You're not going to be very fast. It does get tiring. If you're going to cross an entire parking lot, or you're not going to be walking miles, obviously, but if you're doing a long distance trek, this is not comfortable. For those long distances, you will get exhausted. I actually kept the crutches with me, and if I was getting out of the car and I had to go across the parking lot, the crutches I was able to fly with, while wearing this, you just lift your leg up and you go with it. When you get to where you're going, you can just put the crutches in your shopping cart, or if you've got someone with you to hold them and you go about your day. Now let's talk about durability. This sucker is tough. I mean, it's plastic and metal, and the plastic is really, really thick and durable. This thing got knocked around, dropped, banged around. It's got a few scratches here and there and a few nicks, but you could easily use this several more times if you had to. I mean, this is actually really good construction. I was very pleased with it. If you put it together right, at no point does it feel rickety. I mean, everything's nice and tight fit. It locks down tightly, nothing wobbles.  So I give it A plus 10 out of 10 for construction and durability. You're going to feel very safe on this, and that is important.  It's unavoidable. It got old.  It's basically a peg leg. But on the funny side though is, and this was my favorite, you can really mess with people, because when you're wearing it and you're facing someone front on, your knee, your leg is behind you, so it actually looks like you lost your leg. That was a little bit of a morbid joke I had walking around. It was kind of funny to see reactions for the first time.  They'd be like, what happened? And the second I turned around, I could see that wave of release. It was funny, because it really does look like you had an amputation, which is really not funny, but when you're strapped into a device like this, you take the humor where you can find it. One of my favorites though was the first time I came to class here to teach. I was in the parking lot walking and I saw some of the kids in the background and they're all like, I can see them whispering to each other and they're pointing to me and they're like, miss, miss, miss, miss. And when I turned around, they went, he has a leg. So it was really funny. So you're gonna get jokes.  This is a bizarre contraption to most people. Most people haven't seen this. I went to a doctor's office and the nurses were like, what is that? That's awesome, it's amazing. So I'm actually surprised it's not more well known than what it is because, again, game changer. So that's my review on the I walk free knee crutch. This thing is tough, it's safe, it's comfortable enough and it will let you go about your day and minimize the inconvenience of being off your feet. So I have the link available in the description below. If you have any surgeries coming up or you've got any injuries, check it out. You won't regret it. Thank you so much for watching. And if any of you out there have any tools or martial arts products that you'd like me to review, please let me know and I'll check them out. I'm also really curious to know if anyone else out there has tried this and I would love to hear your thoughts. So thanks again for watching. Please be sure to subscribe and share.


Hello everyone, welcome to this material characterization course. In the last class, we just looked at the applications of X-ray diffraction and we looked at typically three cases. One is crystal structure determination and we also looked at how to look at the stress measurements that is a basic principles of stress measurements and also we looked at the phase identification in a phase mixture. We looked at all those very fundamental ideas behind application of this X-ray diffraction and it is how the intensity is calculated and so on. And today's class, I will just show you some demonstrations through the laboratory videos. I will take you to our XRD lab and then show the equipment details, how the X-ray diffraction equipment look like and what are the primary components and how one would perform an X-ray diffraction experiments in a polycrystalline material. So you will get a basic idea from this though you will not be able to do other detailed experiments since it is only a part of this material characterization course, I thought it would be a very nice idea if you have some detail about how the equipment will look like and what are the basic details about in XRD machines. So if you look at the screen where I started showing this is the Brooker X-ray diffractometer and you can see that it is all enclosed in a big box, you can see it in a long shot and you can also see our one of the scholars in our department is going to operate this machine for us and I will just show you the details one by one. So this is X-ray diffractometer and you have the power console here and on and off and everything so it is a long shot and what you are going to look at again from okay now we have opened this equipment now you are seeing the details of the diffractometer what you are seeing in the background I mean backside the big circular disk is a gonometer it is called a gonometer or and it is also referred as a diffractometer circle and then what you are now seeing is everything in a close-up shot and do not worry you will be seeing this for very long time so you get the details. Now this is the specimen stage where your specimens are kept whether it is a bulk sample or a powder sample a bulk sample is directly kept on this whereas the powder sample is mixed with some medium and it is kept on a glass slider something like that and this is a specimen stage we will talk about it much more detail. So what we need to know from this equipment is the basic components some of the basic components which you require is the x-ray source this is the x-ray source and from where we will talk about some slits and through which the x-ray beam comes out and then it is made fall on this specimen here so and this is a detector this is a detector again which has got lot of slits inside we will discuss about the role of slits and then you have an x-ray detector in this case. So the primary component is x-ray source a sample stage and a detector you can see that all these three are shown in this and one important thing you have to understand is the x-ray source and a detector is kept intentionally on the gonometer circle you just see that the x-ray source and the detector are going to be on the gonometer circle or you can say that diffractometer circle you just observe these details for some clarity these are all on x, y movement for the specimen stage we will discuss about the importance of this movement okay. The specimen also can go in that semicircle fashion in this manner so what I would like to do is before our scholar perform the experiments let me also explain some of the basic components like you can see that what I would like to explain here is you just I will just stop this video here this is the gonometer circle your x-ray source as well as the detector are kept in the diffractometer circle or gonometer circle and the specimen is always kept in the center here the center stage we will now just discuss the basic requirement of keeping the sample in the center of this gonometer circle and there is a we will talk about x-ray optics before we do that experiment so what I will do is let me draw a line diagram on the blackboard in order to appreciate what you are now seeing so I will draw a focusing geometry so what I have drawn is a focusing geometry for x-ray optics suppose if you have the source here and then it goes to the sample and get reflected here and this is a x-ray source which is falling on the sample in the point B and get focused here in F and you see that the angle between this is 2 theta and this is alpha and this is alpha and you can have the relation here with the circle inscribing the angle and what you have to keep in mind whenever you have the x-ray source which goes into the sample and get back to the point F that is the this is incident ray and this is diffracted ray are getting focused again at a point F so you can say that this is a source of x-ray and this is your detector and this is your sample for example so if you this geometry is maintained for all the scanning for all the scanning for variable 2 theta this is completely maintained for all the wherever you keep variable 2 theta this geometry is maintained and we can write so this is also called a Brantano diffractometer where this kind of geometry is used and then I will draw one more schematic which will show the the para focusing of the gonometer as well as the what the sample you are going to scan during various angles of 2 theta so I will draw two more figure then I will get into the discussion so what I have drawn here is two types of 2 theta angle how this Bragg Brantano geometry or I would say Bragg Brantano para focusing method which is being adopted in this particular diffractometer so you have this is a diffractometer circle or gonometer circle which I showed you in the video and this is your sample which I said that so these two there are we are talking about two circles here one is diffractometer circle or gonometer circle the other is a focusing circle so what is this focusing circle depending upon the 2 theta it is going to vary so you see that you see your as I said that your specimen detector and the source should be in a circle so assume that this is a focusing circle and this is your diffractometer circle depending upon the 2 theta it is going to vary at this way or this way so in this case you see that this is the specimen and the specimen normal and this is the incoming source and this is a diffracted beam which is focused and then you see that the specimen is kept in the circle on the perimeter of the circle of focusing so depending upon the 2 theta you can see that the 2 theta is becoming smaller then you see that the focusing circle is also becoming smaller as the theta 2 theta become bigger then you see that it is the you are focusing circle also so this geometry is preserved and that geometry is called Bragg-Brentano geometry and this kind of a focusing is called para focusing and which is being adapted in this particular diffractometer so with this background now you go back and look at the video you will be able to appreciate what I am trying to say now if you look at the video again what I will do is now you can see the goniometer circle and then let me finish that before I go goniometer circle and this is the source and this is a detector and this is a sample which is kept in the center of the goniometer circle in order to maintain this focusing circle which will be here depending upon it is going to vary right now it is small because now the 2 theta 2 theta is here this 2 theta 2 theta is this is a sample you draw a straight line and this is a diffracted beam so this angle is 2 theta so that is going to vary then you see that the focusing circle is also vary so now we will look at much more detail about this about this is about the basic components of the diffractometer we will now show some of the important components here okay this is what we are now seeing here in the screen is the x-ray tube what is the typical x-ray tube one would look at okay so now you have the better view this is an x-ray tube where in you have the target material which is inside and later we will also open this and then show you some of the details of the x-ray tube that this is how the x-ray tube will look like at least you have some idea and which will go into that source what we have just shown so of course this the whole tube is under the cooling system and then you have the beryllium windows through which the x-ray comes out beryllium windows are transparent to x-rays to that detail I would like to finish so have a close look at this x-ray tube so now we will move on to an experiment now before even go to the experiment let me stop here and then explain little more details about this so I said that the x-ray source is here and it is going to come out through this exit window and you remember the x-rays which are coming out of this window is completely divergent beam and it is divergent beam in all directions so it need to be controlled the one of the way to control this divergence is by through slits and we have a typical slits which are popular and then which are kept inside this and then it is being made to fall or collimated beam is made fall on to this specimen and similarly the detector also will have a lot of slits and filters please remember we are interested in taking only a particular x-ray beam for example k alpha and you will in generally if you without the slits you will also come across k beta and so on so the other radiations are blocked by this filters for example k beta is suppressed you cannot eliminate completely but it can be substantially suppressed as compared to k alpha radiation the filters are here and this is a detector it could be a semiconductor device as well so now I think that is the basic idea you should have about this x-ray diffractometer and then now we can even look at how experiment is being performed in this machine and please remember this stages is a rotating stage it can rotate 360 degrees and also it can move on a semi-circle in the stage which I have mentioned now you can see that a typical stage movement in order to save time I am just cutting some of the shots so that you will be able to see this you can see that the source and detector are moving but still that focusing circle is maintained here to in order to mention that I mean preserve that Bragg-Brentano geometry para focusing geometry you can see that the stage is moving it is measuring the beam with various angles 2 theta angles now we will see that the stage will also move in a semi-circle fashion in order to the one of the primary requirement or the use of this the stage movement is you will be exposing the sample in all possible diffracting planes for example if you are interested in particular plane or if it is a powder sample the statistical important statistically important data you will be able to generate if you are able to rotate this stage in all the three directions like this see that the sample sample is coming towards the front and x and y movement and you will you will be able to appreciate that now we will see that the sample will move in this direction it will rotate in this direction that also you can see yeah what you are now seeing is a top view the sample is now completely rotated you can see in that in that semi-circle stage it has moved now it is coming back you can see that and these rotations are completely exploited in the in the case of a texture measurements which we are not showing we are trying to just show the instrumentation detail and what are the possible you know tilt angles and so on and we will simply look at the basic diffraction data which comes out of this sample the sample which is being used as I think alpha silicon oxide powder and you will see that kind of diffraction data which will be obtained from this experiment you can see that the specimen rotation completely it is a 360 degree okay this is just for your information the x-ray tube which we showed earlier now it has opened up this is your anode material it could be you can change this target material based upon the specimen you are analyzing it could be a chromium or you know chromium target copper target and so on depending upon the type of sample you analyze and what the other dismantled part is okay this is a close up view of this anode just for your information and this is the that beryllium window which we talk about through which the x-rays will come out this is a dismantled part not just an important here but just to for an information how the x-ray tube parts are shown so we will now quickly do a one full set of complete experiment and then generate an x-ray diffraction pattern and then we will see what we get so the data collected from the instrument is completely analyzed by the interface software and we will show you how what kind of data you get and then how it is how the background everything is filtered by the software and then you can have a look at it so let the fresh experiment starts with all the possible 2 theta angles we will not hold this video for the complete experiment we will quickly go to that final results so you see that the sample is kept here and then it is being measured at various 2 theta angles I will skip that step because you have no you know you know that how this diffractometer functions I will quickly forward this video in order to save some time okay now you are seeing that how you are dynamically getting that signal we are viewing through a software you see that typical x-ray diffraction peaks are coming on the screen so all this 2 theta corresponding peak belong to a characteristic peaks of silicon alpha silicon oxide which I just said powder a polycrystalline diffraction pattern typical polycrystalline diffraction pattern will appear like this and you can compare this 2 theta value and go to a JCPDS database to identify particular crystal system of course you have a large number of software parameters to derive the data from I mean information from this basic data and this is a typical x-ray diffraction spectrum you will get I will finish this I will go to the another important aspect of the system whatever we are now seen as a powder diffractometer you see that another important source I would like to show is this the equipment which I am going to show you is another very important x-ray machine which measures the residual stresses in an or a stress measurement system which is industrially important the you can see that this is the equipment typical equipment you have a look at it and then we will discuss about the the function functionality of this equipment so this is an extended arm where you have this I will probably I will stop here and unlike the Bragg-Brentano geometry what we have just witnessed before which is not maintained here and here this is an x-ray source x-ray source are here it is not a diverged beam here it is a parallel beam parallel beam and the x-ray source straight away comes there and then you see that there is a typical connecting rod which is being measured which is clamped through a stand here and the x-ray beams are simply falling on this connecting rod and then you have the two detectors besides this in fact they you are looking at the side view so the detector will move on this the curved of of circle stage like this so the x-rays will come straight on the sample and then get diffracted into the two I mean detectors which is kept side by side to this source so the difference between the previous diffractometer and this is here the x-rays are a parallel beam and and you have the direct collection of the diffracted beam and then you try to analyze the x-ray data so now you can have a close look at this arrangement this is one of the unique facility of this our laboratory stress measurements using x-ray diffraction okay you have now better clarity here yes the source which I am talking about is this x-ray source and the two detectors are kept side by side the one advantage with the this kind of setup is you do not have any restriction on the specimen size any specimen which can be fixed into the stage can be brought you can see that now how the scanning is done the x-ray source can rotate and that off circle and then you can see that this is a source now very clearly source and the detectors are side by side the source in the center and two detectors yeah now it scans for all the two theta measurements here so this is a advantage of this particular mission of any component a big component can be scanned and then you will get the data so with that what I think is you have some basic idea if not very detailed idea how the x-ray diffractometer look like and then how the source and the specimens are kept and how the detectors are kept and what is the basic data you get out of this equipment and we also demonstrated to you the stress measurement equipment how it scans there is a big difference between these two equipments and most importantly the x-ray optics behind these two equipments are also quite different and I hope these equipments and this small demonstrations gave you some basic insight about x-ray diffraction laboratory if you are not able to access this laboratory at least you know now how these equipment look like and how what are the basic operations behind this we have not done elaborate experiment here due to the constraint of the time but I hope you had some basic idea and now you can connect what the what we do I mean theoretically what we study in the books and then what practically you can do it in the laboratory when you have an opportunity to look at these equipments in some other labs now you will have some idea how it is done and how the basic data is generated so that was my intention of doing this laboratory demonstration thank you.


And just this talk about, you know, bodies moving and this and that, you know, and you said it's like my whole world. It's like I have to give it my whole world. And from the ego's perspective, that's exactly how it could look. Because that's what the ego is. It's a sense of separate, as if one has a separate sense of self. And all the preferences and all the personal memories and all the goals and ambitions that seem to be private, that seems to be unique, separate than everyone else, that's all part of that concept. That's what I was thinking about was just this feeling that the ego is just kicking in with everything it has. The ego's just seeing more and more clearly what's going on here and it's just like pulling out all the stops. It just feels so strong and powerful at times and that happens. Well, let's look at that one. You know, that is the metaphor that we've used, certainly, that the ego's pulling out all the stops and the ego's having a backlash and so on and so forth and we're describing it in the metaphor as if the ego is an entity, as if it kind of has a life of its own and it exists. And that it has the power to do that. And that it has the power, but it only comes down to the idea that the ego is a decision and the Holy Spirit is a decision and that it comes down to I'm either an ego or I'm not an ego. I mean, it starts to come down to looking at it that way. You can see where that's going beyond the idea that the ego is kicking in. Because then you can see where you can get into talking about it and describing it that way and it just seems to give it a reality. So instead of describing it that way, it probably would be more helpful to just say, deciding for the ego. Everything is just a statement that the mind, by everything it thinks and says and does, it's teaching what it believes it is. You can't leave it at that. I mean, that has to be just a stepping stone or a metaphor because where are you if you say I am presently deciding for the ego? That's a definition of hell. Again, who is that I? And that's what you're getting at. So it's helpful, it's a helpful stepping stone to say I'm not upset because of what happened yesterday or what happened ten years ago or what I think will happen tomorrow. I'm upset because it's a present decision. Now, that would be a definition of wrong-mindedness. A present decision for the ego is wrong-mindedness. And wrong-mindedness is the problem. At one point Jesus said all sickness is wrong-mindedness. It doesn't seem that way to the deceived mind. It seems like there's many, many problems and many, many forms of sickness that don't have anything to do with wrong-mindedness. But Jesus says that decision for the ego for wrong-mindedness is sickness. Now, right-mindedness is the correction for wrong-mindedness. Therefore, we're back to the thing of discernment between the right-minded and the wrong-minded. That's the key, is discernment. The key is in coming to see that it seemed as when we were at Christus down in Cincinnati one day, we had this session somewhere and I remember there was this glee and this joy and the statement was made, I am the right mind. We trace it, trace it, trace it, trace it. You have to come to see that that's the only possibility. That is the only possibility. I am the right mind. I am right-minded. Not I am right-minded some of the time, but the period. And from that clarity, then the wrong mind is dissolved. Another way of saying it is that the right mind must be a constant state because in reality there is no vacillation back and forth between right mind and wrong mind. That's just a metaphor. And if the right mind is seen as a constant state, then the wrong mind is no more because, as we talked about earlier, these two thought systems are mutually exclusive. That is the awareness that they are mutually exclusive, that it can't be both. It never was and it never will be. Right. So that's what this immediacy of salvation is about, is really coming to see that there is no gap between me and my brother because there's just one mind. There is no gap between private minds. So maybe reword what I'm saying when I say I'm deciding for the ego. It's like saying I am the right mind and then tacking on the end of that but right now I'm denying it. I'm going to deny it in this instant. Which is meaningless. If you really look at it. It's like I'm right minded, I'm going to pretend I'm not. I can't say I am the right mind and not recognize it at the same time. A body can say the words I am the right mind. There's no doubt about that. A body can say the words I am as God created me. The thing about it is that's why we go into this so deeply when we talk about preferences, when we talk about ordering of thoughts, when we talk about judgments. Because the right mind is a state where there is no ordering of thoughts, where there is no preferences, where there is no judgment. Images are just seen as images. They aren't arranged. They aren't constructed and put together in a certain way. That's laughable. I mean that's seen as impossible. If ordering thoughts automatically seems to bring about pain and guilt and fear, what's the point? At one point Jesus says that those in heaven, so to speak, or even if you talked about it in terms of the real world, have seen the temptation but have seen the falsity of it. They see no value in judgment. And until I see that, I can't stop judging. You could say it that way or you could say I don't know who I am. So we just said until I see that. Here we are with the immediate salvation. Let's question that until. Salvation is immediate. Unless you so perceive it, you will be afraid of it, believing that the risk of loss is great between the time its purpose is made yours and its effects will come to you. In this form is the error still obscured that is the source of fear. Salvation would wipe out the space you see between you still and let you instantly become as one. And it is here you fear the loss would lie. Do not project this fear to time for time is not the enemy that you perceive. Time is as neutral as the body is except in terms of what you see it for. If you would keep a little space between you and your brother still, you then would want a little time in which forgiveness is withheld a little while. And this but makes the interval between the time in which forgiveness is withheld from you and given seem dangerous with terror justified. It gets to cause and effect. If a mind believes in the reality of the ego, it believes in a false cause. Or we could say a cause was a little C, a capital C for God. And it must be that the mind is holding onto that belief in that false cause now. Jesus is saying here don't project the error, don't project this fear to time. For time is not the enemy you perceive. The old cliches about time heals all wounds. It's not true. Time doesn't heal all wounds. As a metaphor you could say the Holy Spirit's use of time heals all wounds. And in that you have to see as a metaphor because the whole awareness that brings the release is that there is no linear time. There's only now, there's only the Holy Instant. Time is not in the healing. Time is in the sickness as it were. The belief in linear time is the sickness. It's the sickness. So how can what is sick contribute to healing? Does everyone have an understanding of what the word hypothetical means? Every thought that you hold in your mind right now is hypothetical. So even the thought that we're gathered here this morning for a teaching learning session is hypothetical. Anything related to time at all would be hypothetical. You've shared a thought about I have to end, it leaves a session at 12 to go on. That's the hypothetical. You've shared that you're off on Wednesday next week. That's hypothetical. We talked about looking for a job or this and that. That's hypothetical. Anything that you think you've done, experiences that seem to have happened in the past, that seem to be concrete experiences, real experiences, those are hypothetical. Is it the relationship to time that makes it hypothetical? Yeah, the whole projected world and the belief in linear time is what the hypothetical is about. So anything I could talk about or have talked about or think I can talk about is hypothetical. What else, what is there to talk about? If there's no time, there's no space, there's no images, there's no form, how do you talk about that? What we're back with is go for the experience. I know a lot of times to use the example of course groups where you go into the ideas, you go deeper, deeper, deeper, deeper. But, but David, what if you were at such and such a city at night and what if a man came up to you with a knife and said such and such and such and such, you know, hypotheticals, hypotheticals. You know, the mind wants to come up with a lot of hypotheticals. It believes in an objective world. But that's no more hypothetical than an experience that you seem to have actually had. I can't get that. I don't understand that. Well, the teachings that we're coming to is that now is all that there is. And now is free of images in form completely. We say now in the present moment, don't think that you know what that is. You know, we've heard these phrases for a long time, live in the moment. Be totally present. The deceit mind doesn't have a clue. So now doesn't mean just now the five of us sitting here. Right. Now is to the deceit mind unknown. And in the ultimate sense now is all it can be known because it is.  You know, in there as described is there are no bodies in the Holy Instant. At no single instant does the body exist at all. That's a direct line from the I need to do nothing section. Very interesting. At no single instant does the body exist at all. That's what makes this seeming perception as hypothetical as hypothetically going into mountain jacks that gives a different meaning to hypothetical than probably the meaning that you were thinking about when I asked the question. Another way of looking at hypothetical is the belief that cause and effect are a part or that there's a gap between cause and effect.  It's part of a fixed delusional system of distorted cause-effect relationships. The beginning of the psychotherapy pamphlet Jesus makes a reference to that. In the sense that time, the stepping stone to coming to the Holy Instant is to see that all the perceptions that seem to be occurring, that seem to occur as events and situations and happenings over linear time are simultaneous.


Hello and welcome to this presentation on the STM32 G4 High-Resolution Timer. It will cover the main features for managing the complex waveforms required for digital power conversion applications. The High-Resolution Timer essentially addresses digital power applications, such as switch mode power supplies that require high PWM switching frequencies. It allows the drastic improvement of the duty cycle resolution, typically for buck or boost converters. This results in a better output voltage resolution and regulation, and avoids the limit cycling issues which can happen with a regular resolution timer when the duty cycle accuracy is lower than the ADC accuracy. This also allows a finer frequency with phasing adjustments, which is a key parameter for resonant converters using LLC or full bridge phase shifted topologies. The table presents the differences between standard and high-resolution timer for a product running at 170 MHz for both the duty cycle and the frequency resolution. The high resolution is implemented using a delay locked loop, or DLL, which allows the division of the timer input clock period into 32 fractional steps. This DLL requires a calibration prior to the HR timer startup. It must be noticed that the DLL only operates between 100 and 170 MHz, yielding a resolution ranging from 312 picoseconds down to 184 picoseconds as the resolution is scaled with the input frequency. The high resolution is available for any kind of waveform adjustment, period, duty cycle, or PWM to PWM phase adjustment, but not for input capture, performed with the regular input clock from 100 to 170 MHz. Let's now have an overview of the HR timer architecture. Although we talk about a single HR timer, it is actually made up of 7 16-bit counters that can either be used independently or synchronized, each of them having an independent clock pre-scaler. It is equipped with a total of 28 compare and 12 capture units and can control up to 12 outputs. A large central crossbar unit allows the output pairs to be controlled not only by the related timing unit, for instance, timer A for output CHA1, but also by any external event, the other timing units, and or the master timer. A total of 32 set and reset events are available per output. The crossbar is followed by a versatile output management feature able to interface with any kind of gate driver, program the output polarity, the PWM idle and save state levels, insert a dead time, and or add a chopper modulation.  It also features an ultra-fast and asynchronous fault protection feature independent from the system clock. The HR timer is able to handle 10 external events for dynamically modifying a waveform in addition to six fault cycles for protecting power stages. The 10 events can be selected among external ones on inputs and internal ones, typically from comparators. The events allow performance of output set and reset to reset the PWM counters or capture external timings.  The HR timer is also linked with other timers as well as the DMA, ADC, and DAC peripherals via internal interconnections. Let's take a closer look at one of the high-resolution timers' five identical timing units. It is made of a 16-bit up-counter with a programmable overflow value to adjust the counting period. Four 16-bit compare units and two 16-bit capture units are linked to this counter, each with interrupt and DMA capability. A compare event is generated when the counter exactly matches the compare value. Several compare events can thus be generated during a single period to have the output set and reset multiple times per PWM cycle. The unit embeds all control features for a pair of outputs. It can eventually operate as an independent timer. Yet these outputs can also be controlled by other timers. The up counters can operate in three modes. In continuous mode, also called free-running mode, the counter rolls over to zero when it exceeds the value programmed in the period register or restarts counting if it is reset by an external event. This is the most common mode used for fixed frequency converters or for externally synchronized variable frequency converters. In single-shot mode, the counter is started by a reset event and it stops when it reaches the period value set in the HRTIM-PERXR register. Two options are available here. In non-retriggerable mode, the counter reset events are discarded if they occur before the end of the counting phase. Typically, this is to make sure an externally triggered pulse will always have the same pulse width. In retriggerable mode, the counter can be reset at any time. In this case, an externally triggered pulse may have an extended pulse width if it receives multiple triggers closely enough. Each timing unit includes a repetition counter similar to the ones available in standard STM32 timers. It allows offloading of the CPU by decoupling the switching frequency and the interrupt frequency. The counter rollover interrupt can be issued every single, second, third, and up to 256th PWM period. This feature is available both for continuous and single-shot modes. In this case, the repetition counter is decreased on each reset event. The crossbar combines the set and reset events to build the output waveforms, regardless of polarity programming. The events may come from the timing unit itself, from other timing units, from the master timer, or from external events. The timing unit contains two crossbar programming registers per output, one defining the set events, the other for reset events. Up to 32 events can be selected simultaneously. This allows building of periodical waveforms with multiple set and reset events per period. The programming registers are shadowed with preload registers so that the waveforms can be modified on the fly without any risk of having abnormal transient waveforms. In parallel with the compare units, each timer also embeds two capture units. The capture triggers the transfer from the current counter value into the capture register. This is useful for determining external timings and for the auto-delayed mode discussed on the next slide. Typically, it offers the possibility to measure the effective duty cycle in a cycle-by-cycle current-controlled converter where the PWM pulse is terminated when the current comparator trips. The capture triggers can be selected from among 28 sources. External events, adjacent timing events, adjacent output waveforms, as well as update and software events. It is possible to simultaneously enable several trigger sources. Half mode is a feature that allows reduction of computational burden when a variable frequency 50% duty cycle PWM waveform must be generated. This is typically the case for resonant converters where the operating frequency is continuously adjusted by the control loop while the duty cycle must be maintained at 50%. The half mode operating principle is to have a right access to the period register triggering a computation and an update of the Compare 1 register to half the value of the period. Let's consider a PWM signal set on the period event and reset on a Compare 1 match. As soon as a new period value is written into the period register, the Compare 1 value is also updated to the Period 2 value so that the output set event will still happen right in the middle of the PWM waveform. This is particularly useful for continuous mode fixed frequency operation, but it can be used in any other mode as long as the period register needs to be accessed. Auto-delayed mode offers the possibility to have set and reset timings referenced to external events and not only related to the internal time base. Still, a timeout mechanism can ensure a default waveform when the external event is not present or disappears. This HR timer computes a new compare value on the fly based on external event arrival time captured in a register as soon as the event arrives. The delay versus the expected event is programmed in the Compare register, but the Compare event is inhibited until the capture is triggered. When the timeout safety mechanism is enabled, the capture is forced when the counter equals the timeout threshold defined in the Compare 1 or the Compare 3 value. A new capture is possible once the auto-delayed event has happened or when a new period starts. This slide gives a practical use case of auto-delayed mode. The requirement is to build a waveform as follows. The output must be set on a Compare 1 match with a fixed timing versus the counter start value. Here, 2 clock cycles. The output must be reset 5 cycles after the external event falling edge. The output set occurs when the counter is equal to 2 and matches the HRTIM CMP1R register value. The HRTIM CMP2R register value is equal to 5 but is ignored until the external event falling edge occurs. The current counter value is 7. It is captured in the HRTIM CMP1R register and added to the HRTIM CMP2R preload value. This yields an effective Compare 2 value of 5 plus 7 equals 12. When the counter matches this Compare 2 value, the output reset event is finally generated. 5 cycles after the external event falling edge. The uncertainty of 0.5 cycle in the figure is the normal latency due to the capture signal resynchronization. The HRTIM CMP2R push-pull mode simplifies the management of push-pull and resonant converters. The two outputs of the timing unit are alternatively enabled and put in idle state to maintain the balance between the two PWM outputs. In this figure, two identical waveforms are programmed on output 1 and output 2. The push-pull circuitry disables the outputs every two cycles out of phase so that the signals can be built using a single compare value to set the PWM duty cycle. This is also possible without using the push-pull but it would be at the expense of two other compare registers and a larger CPU burden. Finally, it must be noted that it is possible to unbalance the signals and generate asymmetrical waveforms. For instance, a PWM using Compare 1 for output 1 and a PWM using Compare 2 for output 2. The HR timer counters can operate in up-down counting. This mode presents advantages for fixed switching frequency power converters and for motor control applications. The HR timer is able to control up to two three-phase brushless motors and three full bridge converters for driving steppers or DC motors. The up-down mode simplifies the ADC sampling implementation. At first, it allows a constant sampling period since the output pulses are symmetrical to the top of the counting pattern, also called crust of the counting. This is shown on the bottom part of the figure where we can see that the sampling frequency FS is constant from one cycle to the other while it is varying with the pulse width modulation using the up-only counting mode on the upper part. For many converters, the ideal ADC sampling point is in the middle of the output pulse to avoid any conversion error due to the ripple on the output current or voltage. This ADC triggering point positioning requires some calculation in up-counting mode. In up-down counting mode, this is not necessary as the ideal triggering point is always located on the crest, thus slightly reducing the ADC-related computational burden. The UDM bit enables the up-down mode. Most of the HR timer features are available in up-down mode at the exception of auto-delayed and balanced idle modes. The HR timer programming mostly differs with the crossbar programming. The events selected in the HRTIM SECXYR register are coding for both the output set during up-counting and the output reset during down-counting. This allows pulses centered in the counting period as shown on the figure for output 1. The events selected in the HRTIM SECXYR register are coding for both the output reset during up-counting and the output set during down-counting. This allows the creation of more complex waveforms as shown on the figure for output 2. A dead time can be inserted after the crossbar to generate quasi-complementary signals on the two outputs of a single reference, PWM. This allows safe driving of all topologies based on half bridges, including full bridges and three-phase inverters by inserting a dead time during which the two power switches are turned off. This avoids any problem of cross conduction and shoot-through. The dead time value can be individually adjusted for both the rising and falling edges, asymmetrically, to handle any kind of driver or propagation delay. For very specific cases, it is even possible to program a negative dead time and have some controlled outputs overlap. The dead time registers are pre-loaded so that the timings can be adapted in real time without any risk of spurious transitions. This is typically used for adaptive control to optimize the converter efficiency. Last, for functional safety purposes, it is optionally possible to write protect the values or the signs of the dead time with specific control bits. The master timer comes with the five timing units using the same architecture. Its programming is simplified since there are no directly associated outputs nor captures auto-delayed mode or external events management. The master timer primarily aims at synchronizing the five timing units for converters requiring more than two outputs. The six events from the master, period, compare one to four, and the global synchronization are available on all timing units and can be used to set or reset the outputs or reset the timers. The master timer also holds the counter-enabled bits from all timing units. This allows a synchronized start of all timers with a single write access. Last, it embeds the off-chip synchronization logic programming for interfacing with other HR timer instances in case of multiple MCU systems. External events play a key role in the HR timer. They dynamically modify the waveforms typically to implement a cycle-by-cycle current control or to restart the counter following a zero current detection. A set of 10 external events which can be chosen from among 30 on-chip or off-chip sources are used to set, reset, or toggle the outputs, reset the counters, and trigger multiple features such as the burst mode controller, the capture, and auto-delayed compare, the ADC start of conversion, or some protections. The 10 external events are available for all timing units while the conditioning, typically the edge sensitivity, is done globally event per event. A different event filtering scheme can be applied to each timer. The external event conditioning circuitry is a preliminary signal detection stage which is configured depending on the type of external interface or on the amount of noise and glitches present in the incoming signals. The first stage is a four-to-one multiplexer to select the source, usually an input pin or a built-in comparator. It is followed by the definition of the edge or level sensitivity. It must be noted that when the level sensitive option is chosen, the external events are continuously issued as long as the level is active. Last, a programmable digital filter stage allows removal of spurious transitions at the cost of a higher response latency due to the filter propagation delay. This feature is available for external events 6 to 10 only. In many cases, an active event coming out of the conditioning stage is not necessarily a valid event. This is typically the case for current feedbacks. The freewheeling diode's recovery current might be a source of spurious overcurrent detection. It is therefore necessary to apply a specific filtering scheme to the external events used in a given timing unit. Three filtering options are proposed. The blanking mode consists of masking the external events during a defined time window, defined within the timing unit itself or using the other timing units. This is typically the case for leading edge blanking. The windowing mode lets the external events go through only during a specified period of time, again defined within the timing unit itself or using the other timing units. An event postpone mode allows an event to be acknowledged and latched only if it occurs during a given time period and delayed to the end of this period. It is also possible to filter out events based on the number of occurrences. This is typically the case for valley skipping mode in flyback converters. A new period must be started only after a given number of oscillations or valleys. In this case, the external event counter allows the event to be taken into account only after a programmable number of occurrences from 1 to 32. Each timer unit has its own external event counter, which can be applied to any of the 10 available external events. Additionally, the external event counter has two operating modes. In the immediate mode, the event is generated as soon as n consecutive external events have occurred within a period. The event counter is reset at the end of the current PWM period. This mode can be used for implementing valley skipping, for instance. In the cumulative mode, the external event counter is not reset at the end of the period, but only if there's no event during a period. The event will be generated only if it has occurred during multiple consecutive periods, as shown on the right side of the figure after three rising edges on the EEV input. On the contrary, on the left side of the figure, the external event counter is reset after the third period, since there have been only two consecutive events without a third one. Each of the 10 HR timer outputs have three configuration bits. The output is enabled using the OEN bit and disabled using the ODIS bits. All bits are grouped in a single register to have the possibility to enable and disable multiple outputs in a single right access. A disable status bit ODIS indicates if the output was disabled because of a fault detection. The bottom figure is an overview of the whole output stage for a given timing unit. Following the set-reset crossbar, Output 1 and Output 2 reference signals can first be altered with the push-pull and dead-time insertion unit. In push-pull mode, Output 1 and Output 2 are alternatively in run or idle state. When dead-time is inserted, the Output 1 signal serves as a reference to build the quasi-complementary signals and the Output 2 signal is discarded. The burst mode controller allows both outputs to be automatically disabled and re-enabled for a limited period of time. The chopper unit can superimpose the carrier signal on top of the active PWM waveform. Finally, the fault stage can completely disable the output to protect the power switches. The polarity is programmed at the end. The entire HR-timer waveform can be programmed by just reasoning in terms of active-inactive switches, independently from the external gate driver and or interface sensitivity before the polarity is applied. The chopper unit superimposes a programmable carrier waveform on top of the active PWM signal. A carrier generator is started by the incoming pulse and added to the incoming signal by means of an AND gate. This allows interfacing with isolation transformer drivers without having to add external glue logic. The carrier waveform can be programmed with three parameters. The modulation frequency from 1.56 to 25 MHz, the first pulse length to adjust the settling time and the duty cycle to set the sustained current. Burst mode operation is commonly used in power converters when operating under light loads. The burst mode controller allows the outputs alternatively in idle and run states by hardware so as to skip some switching periods with a programmable periodicity and length. The burst mode controller can act on multiple timers in parallel. The outputs are disabled simultaneously with a programmable idle state and the possibility to have a dead time inserted upon burst mode entry to avoid any dead time violations. The burst length is programmable as well as the repetition period when the burst mode is enabled in continuous mode. The burst mode can be started on 32 events and it has multiple burst clock options either coming from the timer rollover event or from independent user programmable period based on the 400 MHz clock. In this example, once the burst trigger arrives, the PWM is active for three periods every eight cycles with pulses skipped for five periods. The burst mode controller counter is clocked and incremented on each timer rollover event. The fault management unit shuts down the PWM outputs and asynchronously forces a user-defined safety state. A software action is required to rearm the outputs. A total of five fault inputs are available each with a programmable polarity, an able bit and a digital filter. It is possible to have one fault input acting on multiple timers for converters requiring multiple synchronized outputs. On the other way round, multiple fault inputs can be merged to protect a single timing unit. The faults are coming from several sources the digital inputs, the built-in comparators for some channels only and the system errors. The system errors are indicating a chip-level abnormal behavior such as a clock security system error, an SRAM parity error, a Cortex-M7 core lockup or a potential brownout condition with the PVD detector. This helps to increase the functional safety level. Last, a global output disable register allows all the outputs to be disabled synchronously in a single right access for an emergency shutdown. The HR timer offers multiple fault protection options. Some are industry standard features. The analog fault uses a comparator. When reaching a user-defined threshold, the comparator tripping causes the PWM output shut down. In digital fault mode, the system is put in a safe state when receiving a digital fault trigger. For the cases where one of the output safe state is active, a dead time can be automatically inserted right after the fault to guarantee a safe transition to the fault state without a dead time violation. The HR timer, however, offers some unique protection features. For LLC converters, the delayed idle maintains the current pulse on the output and the fault state is entered only after it is completed. For the push-pull converters, the balanced idle mode guarantees a perfect balance between the two output pulse widths when a fault is triggered before the converter is actually entering the fault state. The output pulse, which is shortened by the fault, is automatically copied on the alternate output before stopping operation. The fault events can be filtered out by two means. It is possible to do fault blanking so that faults are ignored during specific periods. At the beginning of the PWM cycle, this is also called leading edge blanking or during a window with programmable start and width using the CMP3 and CMP4 compare registers. Another option is to do filtering with the fault counter. Do discard spurious fault information and consider only true errors. The fault counter can operate in two modes, similarly to the external event counter. In the immediate mode, the fault is generated as soon as n consecutive external faults have occurred within a period. The fault counter is reset at the end of the current PWM period. In the cumulative mode, the external fault counter is not reset at the end of the period, but only when there's no fault during a period. The fault will be generated only if it occurred during multiple consecutive periods, as shown on the right side of the figure, after three rising edges on the FLT input. On the contrary, on the left side of the figure, the fault counter is reset after the third period, since there have been only two consecutive faults without a third one. The HR timer has 10 ADC triggering channels with two channels per ADC for the regular and the injected sequencers. This allows up to 10 independent ADC processes in parallel for multiple converters. Each triggering channel has 32 sources, including five from the master timer, five from external events, and four or five for each timing unit. It is possible to simultaneously enable multiple sources for the triggers one to four, when the various trigger instance are clearly defined and do not overlap, as is typical in multi-phase converters. The triggers five to 10 only allow one event at once. Last, the triggering selection registers are pre-loaded for on-the-fly trigger source updates. The ADC triggering rate can be reduced with the ADC post-scaler. This allows the decrease of the number of conversions and ADC interrupt service routines for high PWM switching frequency applications. Each of the 10 ADC triggers can be reduced down to one conversion per 32 counter periods, as shown on the two figures. The right-side figure shows that the ADC triggers can also be positioned during the up or down phase of the counting period using the ADROM or 1 to 0 bits. The HR timer also offers DAC triggers. This allows the possibility to have the DAC values updated synchronously with the timer update events from the master and the slave timers. This is typically used for peak current mode where the DAC is used as a threshold for a comparator. It allows the new DAC value to be applied right at the beginning of the next switching period. Three DAC triggers are available and it is possible to have multiple concurrent sources for the same trigger. The HR timer allows the ease of implementation of slope compensation techniques. This is necessary for peak current mode converters. In this case, the PWM output is turned off by a comparator comparing the current level with a threshold set by the DAC. To guarantee the stability of the power supply in this configuration, it is necessary to apply a descending slope, a sawtooth, on the DAC output connected to the comparator as shown on the figure. This sawtooth must be synchronized with the PWM generation. This is achieved with two DAC triggers, one to reset the sawtooth signal, reloading a start value, and another one to regularly decrement the DAC values. The sawtooth start value and amplitude are defined in the DAC peripheral. The HR timer's dual channel DAC trigger circuitry can be programmed to adjust the trigger generation timings. In the default slope compensation configuration, the DAC reset trigger is sent on the PWM period beginning. The DAC step trigger to decrement the DAC output voltage is generated with the compare two matches the counter value. This register defines the number of steps during a period. The CMP2 value is automatically recomputed by the HR timer after each compare match as shown on the figure so that it can match multiple times per counting period. The compare two register value must only be programmed once, dividing the period value by the expected number of steps. Note that the staircase effect due to the small number of steps in the figure is not representative from a real application and is just for illustration purposes. The high speed DAC allows a much higher number of steps and quasi linear waveforms. All HR timer working registers are duplicated with a shadow register. This applies to the period and compare registers and numerous other configuration registers. It allows glitch free operation when updating multiple registers. The right accesses are done to the preload registers which are transferred in the active registers when an update event occurs, usually at the beginning of a PWM cycle. Two control bits allow handling of the preload mechanism. A preload enable bit preen in each timer globally enables the register shadowing. The update disable bits, MUDIS and TXUDIS can temporarily suspend the update event for complex HR timer updates or on the fly HR timer reconfigurations. Numerous update trigger sources are available within the timer itself from other timers such as master or timers A2F, other on-chip sources such as general purpose timers or following DMA burst mode. The HR timer is able to generate interrupts from a total of 100 sources. They are dispatched on eight interrupt vectors as following. One for each timing unit and the master timer plus one vector dedicated for fault management. The table lists all the sources and gives a brief description of each. The HR timer can also trigger DMA transfers from a total of 91 sources. They are dispatched on seven DMA channels, one for each timing unit and the master timer. The table lists all the sources and gives a brief description of each. The DMA can also be used to dynamically reconfigure the HR timer during converter run times. This is done using the DMA burst mode. Once it is triggered, the content of a table in the memory is transferred into the HR timer control and configuration registers. The DMA burst control registers specify the registers to be updated one by one. Once the transfer is completed, a global register update is issued to have the new values transferred from the preload to the active registers. The HR timer peripheral can be active only in run and sleep modes. In stop and standby modes, the HR timer must be disabled. This slide gives a practical use case of the HR timer. It shows how to generate the PWM signals for a triple interleaved converter. Three step-down converters are running in parallel with a 120-degree phase shift to minimize the output voltage ripple and to spread the input current demand. They must be synchronized to guarantee a constant phase shift and eventually switch off one phase, adjusting the phase shift to 180 degrees. This is done using the master timer. The events generated on master's period compare one and compare two, reset timers A, B, and C respectively. The pulse width on TA1, TB1, and TC1 outputs are then programmed using the compare one register of each of the timing units as per the control loop demand. If we consider the TA1 output, it is built with the output set on master period event, output reset on timer A compare one event. The output TB1 is set on master compare one event and reset on timer B compare one event. The output TC1 is set on master compare two event and reset on timer C compare one event. Note that it is very simple to have an ADC trigger issued in the middle of the pulse width using the spare compare registers in each timing unit. The peripherals listed here influence HR timer behavior. Please refer to the corresponding training for more information. Multiple application notes and user manuals are available for the HR timer for the STM32F334. They are partially valid also for the STM32G4 and can help developers better understand how to use the HR timer.