[Amps] Shorting Sticks

TexasRF@aol.com TexasRF at aol.com
Sun Apr 24 17:57:29 EDT 2005


There was one more "gotcha!" failure mode that comes back to mind: My 2m 8877 
PA hv power suplly uses two 100uf 3000v oil filled caps in series. The big 
power bleeder resistor had gone open as mentioned previously so the shorting 
device was applied to the plus and minu terminals to discharge the caps.

Imagine my surprise when after shorting them, I found both capacitors still 
had a hv charge on them! The shorting stick just made all those stored 
electrons divide between the two caps.

So, not only should the B+ to B- be discharged, each series capacitor should 
also be discharged.

You just can't assume anything when working with these hv circuits.

73/k5gw


More information about the Amps mailing list