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200V cap w/110vac safety margin?

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HellTriX

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I'm just making a simple filter for my pwm circuit so I can do some better measurements of my circuit and wanted to know the safety margin for caps.

I don't really know what is the safety margin so I just sort of wing it. But, this time, I got some pretty huge caps and if they explode they could do some serious damage. Therefore I seek advice.

The caps in question are 200VDC 2000uF Electrolics (Sprague Powerlytic). And just wanted to make sure I can use them behind my full wave bridge rectifier, from a 110VAC source (118.8VAC measured). This gives a peak voltage of 202.79V which would usually be less do to voltage sag, wire resistance, and diode losses. The 200V caps should be slightly under rated so technically they should handle a bit more then 200V.

What do you guys think? Is it safe to use these? (was thinking of building a nice shield to put them behind just-in-case :p

TriX
 

tcmtech

Banned
Most Helpful Member
You should only get a 170 volt peak with a 120 VAC line sourse. 200 volt capacitors are commonly used on 120 VAC line rectification applications. As long as you dont hook them up backward you will be fine.
 

Hero999

Banned
400V is used for the filter capacitors here in Europe (230VAC) so 200V will be fine for 118.8VAC.
 

HellTriX

New Member
Thanks guys. I am gonna use them.
Almost done building the new circuit then I will design the filter and add the caps and try it all out and maybe even give a report back of how it went.
 

Mike_2545

Super Moderator
You should only get a 170 volt peak with a 120 VAC line sourse. 200 volt capacitors are commonly used on 120 VAC line rectification applications. As long as you dont hook them up backward you will be fine.
Backwards? We are talking about AC not DC, right?
 

HellTriX

New Member
Backwards? We are talking about AC not DC, right?
Eh? AC into bridge, DC out of bridge.


Hopefully this capacitor is downstream of the bridge. Otherwise it will blow up.
Yip, not quite that noob here :p
Then again I forgot a resistor before my zener and gave my 12v reg a full 110V, that was some nice magic smoke.


The cap bank is built and tested. I still have to test it under load. Got the zener thing almost sorted, but I cant find any more 12v regs so might have to delay till tomorrow. I may have damaged the zener too as I'm only getting .07V when I should have 12v. So gonna swap zeners and check.

*EDIT* Yip, just checked with a new zener and got 11.7V. Now just to find another 12v reg.
 
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