I need 5 or 6 X2 caps of .01uf at somewhere around 400v value with long leads. does anybody have a source?
400V (not 400v) is probably a DC voltage rating, not a value. X2 caps are AC rated, not DC rated - although they may sometimes have a DC rating too.
0.01uF (not .01uf) is a typical X2 value so you should find them in any decent electronics catalogue.
Long leads might be a problem. Why do you need long leads?
0.01uF (not .01uf) is a typical X2 value so you should find them in any decent electronics catalogue.
Long leads might be a problem. Why do you need long leads?
You could add some extra wire, or use a small subsidiary PCB or tagstrip.
Sadly, long lead components are becoming more rare.
Sadly, long lead components are becoming more rare.
Bummer, I'll probably have to solder some lead on to make them longer although I don't like doing that.
Digikey has plenty of Kemet and Panasonic X and Y caps with long leads. An example:
http://www.digikey.com/product-detail/en/PHE820MB5100MR17/399-7601-ND/3465773
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Actually I could have used less but I wanted a safety margin and you get wide gaps in the VR of these caps ie 275, 305, 310 but after that its hard to find anything until you get to 400V or 440V. I just settled on the highter number rather than the lower one.
The design of an X2 cap already includes a safety margin, so you don't have to include one too. You just pick one appropriate to your mains voltage. They are failsafe, which often means that they slowly lose capacitance over a number of years.
I hope that the bridge rectifier is on the secondary side of the transformer. A typical X2 capacitor is on the primary side of the transformer.
You don't need an X2 cap on the secondary side, as failure here has less catastrophic consequences than a short across the mains. Just pick a cap with DC rating about twice the peak AC voltage.
What is the secondary voltage of the transformer?
What is the worst case (highest) voltage that one could get from that transformer?
Multiply that worst case value by sqrt(2).
Select a capacitor that can take that 1.4times highest voltage.
eg dual secondary 25+25Vac, has a worst case output of ~254/230*(25+25)*(1+regulation) ~ 60Vac
Times 1.4 equals 85V
Select a capacitor that can take >=100V
It will never fail due to overvoltage.
What is the worst case (highest) voltage that one could get from that transformer?
Multiply that worst case value by sqrt(2).
Select a capacitor that can take that 1.4times highest voltage.
eg dual secondary 25+25Vac, has a worst case output of ~254/230*(25+25)*(1+regulation) ~ 60Vac
Times 1.4 equals 85V
Select a capacitor that can take >=100V
It will never fail due to overvoltage.
O.K. guys, this is across the secondary and I have those caps handy, I will use them. I added something new to my quite limited electronic knowledge.
I couldn't see why it would make any difference as to cap quality because AC noise is AC noise but I see now.
You want to parallel the x-cap to your anode winding of mains transformer? Why that?
Our poster has not told us he has an anode.
He has not told us what he needs.
He has told us what he wants.
Combining this with the first posting I conclude this is the high-voltage winding of some tube amp mains transformer. Ok?
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