caps: volts and watts

[Somicide]

I have an over abundance of hi volt caps, like 120V and 250V; does this mean i can't use them?  and what about wattage?  is there a recommended wattage to use?  Thanks, i realize i've been asking stuff nonstop.

[ethniccheese]

Are these electrolytic, polyester, ceramic...?  Voltage ratings should not matter as long as they are over the maximum voltage they will be subjected to.  Size may beome an issue with electrolytics and some film caps that have these ratings, however.

[smoguzbenjamin]

Questions are good things.

If you don't mind HUGE caps on your fx board then it's fine I'm not sure about watts... I only look at if the rated voltage is sufficiently over the voltage I'll be putting through it.  :? Shouldn't be a problem though.

[petemoore]

Don't know that I've seen any watt ratings

[smoguzbenjamin]

Yeah I was surprised too, I've also never seen a wattage rating but then again I've never thoughroughly examined a cap, only looking for a number ending in V or uF So I thought I wouldn't make an ass of myself and take a look first

[Peter Snowberg]

Capacitors with watts ratings are intended for ballast applications. They are commonly used for AC motors and HID lighting.

Watch out for these. If they were made in the US prior to 1979, they may contain PCBs, not the printed circuit boards we know and love, but Poly-Chlorinated Biphenyl oils, which are carcinogenic and cause liver and central nervous system damage. I don't know when and if their manufacture was made illegal in other countries.

Be safe,
-Peter

[Somicide]

thanks for the heads up on the cancer-caps, i have this huuuge assortment i found from an old TV/Radio repairshop.  no transistors or diodes that i need, unfortunately, so small bear's gonna get some business.  hopefully my trans-BMP will work well.

[acromarty]

Large electrolytic capacitors used in power supplies and other high speed switching circuits have power ratings. The power is dissipated by the capacitor's own internal resistance as it charges and discharges. The larger the capacitor and the faster the charge/discharge cycles, the more power it needs to dissipate. Most switching power supply caps are "low ESR" types (ESR = equivalent series resistance) to minimise this power dissipation. It also makes them better at filtering.