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12volt power supply - Printable Version

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12volt power supply - David - 04-18-2014

Picked up a 2amp 12volt power supply figured i could use the transformer for bucking line voltage. Open the unit up very basic on/off switch plus pilot light on primary side. Secondary 24volts out center tap, 2 didoes 4700uf 16 volt ecap 150ohm bleeder resistor ok that looks real simple. looking at the center tap there a small tube about one inch long one fourth inch dia. What the heck is it? I replaced the diodes ecap and bleeder just to see if it works. Output 16volts dc no load. two little wires in the tube glow down at the base. The thing was made in Japan guess late 60's early 70's. Sorry not able to find a model number name American Electric. David

RE: 12volt power supply - morzh - 04-18-2014

Why make us guess when a picture always speaks louder than words.

RE: 12volt power supply - David - 04-19-2014

Sorry about no picture my cameria died about 2 weeks ago. The one in my phone will not do close up. David

RE: 12volt power supply - morzh - 04-19-2014

You have no cam....your computer has no cam either?

Could the tube be a.....fuse?

RE: 12volt power supply - codefox1 - 04-19-2014

Depending on the application current needs, a wall wart innards might work out. Who doesn't at least a shobox full of these critters?

RE: 12volt power supply - morzh - 04-19-2014

Yeah, those tend to multiply. I have some from 10 years ago. Icon_smile

RE: 12volt power supply - jerryhawthorne - 04-19-2014

If the intended purpose was to salvage a transformer for use in bucking as David indicated, I doubt a wall wart is going to hack it. Radio Shack sells or use to sell cheap a 115V to 12V center tapped transformer that many have used for that purpose dirt cheap. I suspect more compact than a full blown power supply transformer.
Jerry

RE: 12volt power supply - David - 04-20-2014

Thanks folks for the replies. I only paid one dollar for the thing plus about seventy five cents for the diodes and ecap. Those parts I will remove and use the unit as a bucking transformer for small AA5-AA6 radios. I will take the glass tube thing by a friends and let hin take a picture in the next few days. David

RE: 12volt power supply - morzh - 04-20-2014

Many wallwarts have switching topology. The switching transformers cannot be used for bucking or for that matter for anything other than switching. They differ in principle, they are flux storing devices, not simple impedance matchers like regular step up/down transformers.