Bouncing ball analog computer


[Eric Archer] constructed an analog computer to model the physics of a bouncing ball. The core is a TL074 opamp that does all the integral math. He had no trouble finding descriptions of analog computers, but how to set the initial conditions was rarely covered. The controls include potentiometers to set the initial velocity, force of gravity, and coefficient of restitution (how much energy is lost in the bounce). The output is displayed on an oscilloscope. He mentions that this output could be used in electronic music, citing Aphex Twin’s Bucephalus Bouncing Ball. Watch the video below for a demo of all the features.

13 thoughts on “Bouncing ball analog computer

  1. That’s really, really cool. Analogue circuits are hard to find these days, much less ones that do math!

    also, I’ve never tried lone star beer. I can only hope that drinking it makes me half as cool as this guy.

  2. Well that’s a pretty, excuse me
    (takes a pull on beer)
    -a pretty interesting project.

    If anything I liked the beer in there just because it’s probably what would be happening if you were over visiting some evening anyway.

    I love analog.
    (and a good beer doesn’t hurt when the workin’s done either friends)

  3. That guys work bench would look exactly like mine if he had a few empty beer bottles laying on the ground underneath it! But the analog computer is cool though, I’m forwarding this page on to my grandpa who is an old school mad scientist electronics guy. The only digital stuff he touches is the 4017 cmos decade counter, and refuses to use any other digital stuff. He’ll like this.

  4. @Mike c:

    That’s not unusual.
    My Rad Shmack has a few analog heads that are always coming in for parts to keep older gear running or to mod it in some way.

    I always have to ask what they’re building and if it’s diabolical.
    If so the better of course, but hope springs eternal.

  5. That’s really cool. I actually know that guy, but I haven’t seen him in probably almost 2 years. I used to just hear talk of how he’d been to Space Camp as a kid, but on his website THERE IS ACTUALLY A PICTURE.

  6. I tinkered with analog computing many years ago, including some ballistic and orbital simulators. I also worked on hybrid computers when digital was too slow or expensive to get decent simulation data, and the core was all analog with digital inputs and outputs. Using that method, you can program the parameters from a digital system and run the simulation in analog, then “harvest” the results to digital files. Great for heat flow and thermodynamics as well as flight paths and characteristics of weapons systems.

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