Dissipation factor of capacitors  is a function of temperature and frequency (of supply voltage). In the other words, capacitors’ losses vary with temperature and frequency. Dissipation factor of capacitors has three additive components. The first and second components are related to changing of capacitors’ parallel and series (ESR) resistances due to temperature. Since both of these resistances increase with temperature, so these two components always are positive. The third component is related to intrinsic characteristic of dielectric material. Dielectric dissipation factor may increase, decrease or even remain constant with increasing temperature. So, cleverly choosing of film capacitors may decrease the probability of capacitor overheating and extends its overall life.

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