Can I substitute a slightly different HV capacitor for a blown one?
It is not always possible or convenient to obtain an exact replacement high voltage capacitor. What will the effects be of using one that is a slightly different value? First, the voltage rating must be at least equat to that of the original. It can be higher but never never lower or you will probably be replacing it again in the very near future. Now for the uF rating: Unlike a conventional power supply filter capacitor, the capacitor in a microwave is in a voltage doubler and effectively in series with the load (magnetron). Therefore, its value **does** have an impact on output power. A larger capacitor will slightly increase the output power – as well as heat dissipation in the magnetron. Too small a capacitor and the doubler will not produce full output. As an example, the impedance of a 1 uF capacitor at 60 Hz is about 2.5 K ohms. The cap is in effect in series with the magnetron. A 1 kW magnetron running on just over 3 kV RMS is about 10 K ohms. These are really really rough calc
Related Questions
- Another, but slightly different example, might involve GCSE Geography students who are required to collect extra fieldwork data over the summer holidays?
- Why did my piece of handmade jewelry look slightly different in color, size or shape from the picture I saw on the website?
- Can I substitute a slightly different HV capacitor for a blown one?
