dummy math question capacitance

[michaelj]

Dyslesics are us.. Could some one please answer the following I keep getting mentally turned around.

Two 150uf @350vdc electrolytics IN SERIES [w swamping resistors]??

What is the actual capacitance?

Is the voltage limit simply doubled / [700vdc]?

Looking at the power supply in a Bedrock 1200 with right at 600vdc after the diode rectifier. [before the first filter above]

Having trouble locating 150uf @ 350vdc[+] and wondering is there is another way to arrange this firsr filter with readily available electrolytics ?

I haven't been able to locate 150uf , certainly not in the voltage range 350 and up.

Thanks for answers, ideas and/or directions to find replacements.

Mike

[tboy]

Two 150uf @350vdc electrolytics IN SERIES [w swamping resistors]??

What is the actual capacitance?

75uf.

Is the voltage limit simply doubled / [700vdc]?

Yes.

[Steve Conner]

Yes. Also remember that the tolerances on electrolytics are -20%, +80%. So if you have a schematic there that calls for 150uF, it could have been anything between 120 and 270uF.

Capacitor values were standardized a while back, such that nobody makes 150uF any more. The preferred values are 100, 220 and 470, though you sometimes see 330 and 680 too.

I'd just use 220, since it's a solid-state rectifier, so there's no maximum capacitance to worry about.

[michaelj]

Thanks guys, MJ