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Regulated 12v Supply, Hum reduction

bigkim100

Apr 17, 2013
270
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Apr 17, 2013
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270
Ok, so I have my old 12Vdc 6 amp power supply, with TONs of fresh electrolytic capacitors, but Im still getting a bit of 60cycle hum. I doubt that I will ever be pulling more than 2 amps from it, but it is rated at 6 amps.
Can someone suggest a choke, capacitor combo that will finish off the last bit of hum...something I can get from EBAY.
I remember back in the 70s when I had a power supply for my Radio Shack CB Radio with a bit of hum, I pulled a random choke out of a box of military surplus components from POLY PACKS (remember them). I had no idea of its rating, but I had zero hum from then on.
15 years later I sold it, and it was still perfect, and I never knew what the hell the choke was.
 

Audioguru

Sep 24, 2016
3,656
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Sep 24, 2016
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3,656
Most power supplies use a full wave rectifier bridge that produces 120Hz, not 60Hz. Then one or two of your rectifier diodes do not work.
 

bigkim100

Apr 17, 2013
270
Joined
Apr 17, 2013
Messages
270
Its only a slight hum, but noticeable. I did not realize that the bridge rectifier changed it to something other than 60 hz.
This does use a big, chunky full wave diode bridge module, mounted to the case for heat dissipation, I can only guess.
This is all followed by several high value electrolytics.
I changed the electrolytics to fresh ones, since I had them kicking around.
 
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