• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Built-in bleeder in ASC?

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
I connected my DVM to the second cap in my PSU and powered up and after five or so minutes powered down. The voltage quickly dropped to zero without a bleeder resistor installed. I then did the same check on the first cap with the same result.

Questions-
1- Is there a bleeder resistor built into ASC caps?
2- If "No" to question 1 then is the rest of the circuit acting as a bleeder and discharging the caps?
3- If "No" to 1 and 2 could the 8H choke between the caps be acting as a bleeder to discharge them?
4- If "No" to 1, 2 and 3 what the heck is discharging the caps? Do ASC caps just discharge quickly when power is removed?

Enquiring minds want to know. I was apparently doing nothing when I thought I was discharging the caps using my 220K "Resistor-on-a-stick" custom made cap discharger :D .
 
dshortt9 said:
Sherman, I just did the same thing and my ASC caps discharged as if all by themselves. Never saw this before. Half wave rect, choke filtered, through a 15K resistor.
By the way, I tickled mine up to 1000v without failure, and less than 1ma of current.


1000V? Wow, I don't know that I would have tried that. My caps are rated at 370VAC so I figured they'd be fine at a ~400VDC.

My PSU is tube full wave rectification (5U4-G), 40uF ASC cap, 8H choke, 100uF ASC cap.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.