3000W Chinese Gensets Info.

That's correct. The charged cap can pit the points as the points close. It all depends on the size of the cap and how much energy it can hold. The condenser is sized so that it's large enough to prevent a spark as the points open, but small enough to prevent point damage when points close.

In the design I described, I added a resistor and diode across the despiking cap. After the relay contacts open, the cap gets discharged through the added diode and resistor. The cap will be discharged whenever the relay closes again.

BTW, there are different types of capacitors, some having extremely low failure rates. The military also uses a stringent component derating criteria. In the case of capacitors, actual current and voltage seen in the circuit is well below max component ratings. Not like in commercial usage.

Sal

N9WOS wrote:

And a snubbing capacitor is far from ideal. If it is a low value cap then it will have the same effect as a cap/condenser in an ignition. It will hold off the voltage spike long enough for the points to open (not arc) but the peak voltage spike will potentially damage the insulation on the inductor the contacts are driving. If you use a large capacitor to absorb the energy and prevent the large voltage spike, then your contacts will be subjected to a very large current spike when they engage. The cap is completely discharged. So it is almost like closing on a dead short. It doesn’t do the contacts any good.