[Amps] equalizing resistors

Vic Rosenthal rakefet@rakefet.com
Fri, 01 Mar 2002 07:54:06 -0800


Bill Russell wrote:
> 
> I am replacing the filter cap in the hv section of my Thunderbolt. I will
> be using 2 caps in series. The power supply filter is the choke input type
> using a swinging choke. It supplies 2200 volts. Do I need to add equalizing
> resistors across each cap. Depending on who I talk to, Ive been told I do
> need them and than again I dont need them. Which is correct. If I do need
> them, what size should they be. 100k at 10 watts is what Ive been told.

If you do not use equalizing resistors, the 2200 volts will divide across the
two caps in inverse proportion to their leakage resistance.  With electrolytics,
there often are wide variations in leakage resistance, so it's possible that you
could have much more voltage across one than the other.  I'm not sure about
oil-filled capacitors.

100K is good value.  If each resistor has 1100 volts across it, then 11 ma would
flow and the resistor would dissipate 12.1 watts.  

73,
Vic, K2VCO
Fresno CA