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Confused: 12V AC to 12V DC, simple bridge rectifier? Answered

I have a 12V AC power block powering some lights, I want to take one channel off that block and power a 12V DC strip of LEDs, could I just use pretty much any single phase bridge rectifier? They all seem to be rated in the 100's of volts... I know I could do the same thing with a bunch of diodes, a zener and a resistor, but I'd like to just use a packaged chip (because I'm lazy...)?

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steveastroukBest Answer (author)2012-07-21

Yes, any rectifier will work just fine.

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csavage6 (author)steveastrouk2012-07-21

Thanks, appreciate it, it's been too long since I went through all the electronics theory, most days now it's pure 12v DC in automotive...

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nirala (author)2013-06-11

yes, you are right Mr. csavage6. I little understand because I am poor in English. my language is Hindi. Plz you use easy sentences.

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mpilchfamily (author)2012-07-21

Yes any rectifier will do but be aware of the voltage drops the rectifiers have. You could loss a volt or more to the rectifier. So you'll have 12VAC going in but only 10 or 11volts DC out.

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csavage6 (author)mpilchfamily2012-07-22

Ah yes, good point, thanks

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rangenmi (author)csavage62012-07-23

Also, dont forget a decent sized cap in parallel with your load. Itll minimize the ripple voltage giving you cleaner DC

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framistan (author)2012-07-21

AC voltage changes polarity (plus and minus) 60 times a second. DC stays the same polarity. A bridge rectifier will make all the AC "pulses" of voltage be POSITIVE pulses. However, the peak of those pulses may be about 18Volts. So your LED's will actually be getting pulsed by more than 12Vdc if you do that. The LED's may be able to handle it if you put a larger (more ohms) series resistor in your circuit. If you apply wrong polarity to LED's, you will burn them out. If you do not have a proper RESISTOR in series with the voltage, you will burn them out. There are many instructables on how to use LED's and DIODES on this site. You need to do a little reading of those before starting your project.

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csavage6 (author)framistan2012-07-21

Thanks for taking the time to type a reply.

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