substitute cap for 680uf

[t.j.]

local store does not have 680's in any voltage. or any 340 polymers! what is the closest i can get that might work for what i need! have friend in big city going to store for me! have been doing search on it, but runnen out of time, please an tanks!

[Uranium-235]

Re: substitute cap for 680uf

eh, if its not a circut on a motherboard VRM, I would not recommend going half with a polymer. a 680 or 820 polymer should be fine

a 820 lytic should be fine to, just make sure the esr the same or lower, unless its a general purpose circut (not one that needs like computer-like power filtering)

oh yeah and make sure the voltage is the same or more. It can be more. even double most of the time

[t.j.]

Re: substitute cap for 680uf

sorry, should have stated was out of rca 51 inch lcd psu. on the out side to main! they sit under a heat sink so size may be issue! will call store an see what they have, thanks for your time!
the store caries nicolson an illinos caps! went through bad cap/company list an did not see them listed, so here's hopen.

[t.j.]

Re: substitute cap for 680uf

we only have 3 stores in edmonton i guess that suply components an none have 680 or 820 or any polymers! bs i say!! lol. online i go! o wait i here! haha going shopping!

[t.j.]

Re: substitute cap for 680uf

caps needed are
1000uf 16v 105c 10-15,, checked badcaps stoock an have nichicon h2 1000uf 16v 105c 10-16. should do!
1000uf 35v 105c 12-25. in stock are rubycon zlh 1000uf 35v 105c 12.5-20. will the 5 mil on height matter?
680uf 25v 105c 10-20. in stock are rubycon zlj 680uf 25v 105c 10-16, again, will height matter? thanx for your time!

[selldoor]

Re: substitute cap for 680uf

We dont know if height will matter - only you can tell the space they have to fit in. As a general rule you get the largest size that will fit in the available space for the uf and voltage required.

[t.j.]

Re: substitute cap for 680uf

thanks Selldoor, they under heatsink! so will fit better then the last ones! lol.
peace

[Uranium-235]

Re: substitute cap for 680uf

ok, NEVER use polymers like this on that type of circuit. In addition, the half rule DOES not apply cause tv/monitor type power circuits usually too much voltage. The only times you'll usually run into polymers that high a voltage are ones with low uf, like 330 max, You might be able to get away with using 16v 820's polys to replace those 16v 1000's though. But iv'e heard bad stories about using polys on 120 AC->DC filtered circuits resulting is very poor performance

the rest of them, use lytics only. And don't use crap ones. General purpose lytics on these types of circuits don't last long, if work properly at all.