Voltage Doubler Capacitor Voltage Rating (Best Practices)
« on: November 27, 2020, 05:48:33 PM »
I'm recapping a power supply with a voltage doubler, and the can caps had been replaced at some point with 150V rated parts. I don't know what they were originally spec'd at, but I've always just looked at max HT and selected the next highest voltage rating for safety margin. It will be a PITA to fit anything larger than a

Looking at the schematic, I see that either of the 80uF caps in the doubler only see half of HT, but if one failed short, the other's going to explode, and either may take out my power transformer. Whats the safe voltage rating to use for these 80uF caps?


abbey road d enfer

Re: Voltage Doubler Capacitor Voltage Rating (Best Practices)
« Reply #1 on: November 27, 2020, 06:24:26 PM »
ILooking at the schematic, I see that either of the 80uF caps in the doubler only see half of HT, but if one failed short, the other's going to explode, and either may take out my power transformer. Whats the safe voltage rating to use for these 80uF caps?
If on egoes short, one of the rectifiers or the xfmr will give up anyway, but there is no way the other cap gets double the voltage.
Who's right or wrong is irrelevant. What matters is what's right or wrong.
Star ground is for electricians.

Re: Voltage Doubler Capacitor Voltage Rating (Best Practices)
« Reply #2 on: November 27, 2020, 06:36:34 PM »
Ah...of course. Thanks!

ruffrecords

Re: Voltage Doubler Capacitor Voltage Rating (Best Practices)
« Reply #3 on: November 28, 2020, 04:11:49 AM »
150V rating is a bit on the shy side. 117V times root 2 is 165V and that is with nominal mains. Good design practice would allow for 10% above nominal mains so I would rate them at 200V to be safe.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'


 

Related Topics

  Subject / Started by Replies Last post
10 Replies
4293 Views
Last post November 12, 2005, 02:37:45 PM
by smallbutfine
21 Replies
1687 Views
Last post February 23, 2019, 12:43:49 PM
by rollmottle
8 Replies
1398 Views
Last post March 12, 2019, 05:10:55 AM
by abbey road d enfer
7 Replies
517 Views
Last post April 28, 2020, 04:55:43 PM
by substitute