bipolar 24 volt power supply

[Dougplo]

I used GGG bipolar schematic and modified it by using 7824 & 7924 regulators. my capacitors where rated 50v. and my transformer was rated 44 volts @ one amp. when I plugged it in the transformers primary & secondary heated up & the 1000uf capacitors smoked. any Idea's on where to start trouble shooting, and are my values correct?

[Coriolis]

Hmm...if the tranny heated up, you must be drawing a lot of current somewhere. Got a short somewhere? Solder bridge?
Also, did you have anything loading the psu - like pedals hooked up to it, I mean? I'm not sure, but if the tranny is rated 44V @ 1A, and your not drawing 1A, but less, then the voltage on the secondary could very well be higher than 44V - perhaps even higher than the 50V your caps were rated for...
Maybe go to 63V caps?

C

[Joecool85]

Sounds like you might have reversed polarity on one of your caps...

Can we see some pics of your board?

[Nasse]

I think the transformer secondary voltage is too much for the application, when rectified it is too much for the caps and regulator chips. Caps got too much voltage and exploded perhaps, dunno if 63 volts is safe enough, perhaps not, I believe they are dangerous too.

Perhaps you could use some high voltage caps and measure the rectified voltages with a multimeter. And I looked the 7824 datasheet it says 30 volts maximum input is specified.

I think the chips do enormous job transforming that extra voltage to heat. I would look for another transformer, something about 24... 30 volt I believe

Do a seek about EXPLODING CAPACITORS (wear helmet and safety goggles, more things "do not try this at home" at dudesons.com)

[BrianJ]

Does the transformer have multiple primaries for different countries? 

[Dougplo]

My transformer was blown, but the caps were ok. So I lowered the voltage to 27 volts and it worked perfect.
Thank You.