Series connecting PS caps?

[jevs]

Anyone used caps in series to get a higher voltage rating for their filter caps?
I am having a hard time finding any reasonably priced caps for over 100 Volts with a decent uF rating. I was thinking of buying a couple 80 Volt caps and setting them up in series to get 160 Volt rating and half the capacitance. Just wondering if anyone has done this for filter caps.

[limbo]

Yes, that can be done. You need to place a resistor (say 22k/0.5W)) in parallel to each capacitor to define the DC voltage in the middle. Without these resistors the mid voltage would be floating and only defined by the difference in leaking of both caps.
If one cap is leaky and the other very good, the good one could get too much voltage.

John

[JRoque]

Do these help?
http://www.halted.com/ccp18261-cap-1...0ja-rep300.htm
http://www.mouser.com/index.cfm?hand..._pcodeid=59805

JR

[jevs]

Too small, I need like 17,000 UF and 33,000 UF. It would take too many of those and cost as much as finding a bigger one.

[fyffe555]

I know it's old but have you tried Ebay. There's a seller 'capacitor12' who sells just that. I got some 100v 33,000uf and some 250v 12,0000uf for under $30 a pair a while back, quoted as 'computer bus grade' - his stock changes and I don't know if he has 160v, maybe drop him a message.

160v and 33000uf, that must be heck of a PS!

Andrew

[Bloy2004]

Jevs,
Have you tried ebay? I picked up a lot of four 20,000UF 100V (150surge) for 17 bucks plus shipping. I don't know how old they were, but they look and act like new.

Set one of your ebay searches to the electrolytics and check often. Deals come up all the time. Some are buy now.

Bloy

[fyffe555]

Another thought; Is the PS going to supply more than one motor driver? You can get very good results putting a smoothing cap across the input supply of each driver. Some drivers recommend an additional smoothing cap there anyway..

Andrew

[jevs]

I have been searching ebay. I have found a few that will work on my 56 volt supply, but the 112 volts supply is harder.