# 12vdc transformer



## Just Cliff (Nov 27, 2008)

I need to find a transformer for 12vdc. The 12v motor is rated at 14Adc. Anyone know where I can get my hands on a 15 to 20adc transformer.....Cheap?


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## TnAndy (Sep 15, 2005)

You need a power supply, not just a transformer, assuming you are coming from 120v AC to 12vDC.

Use the power supply out of a junk computer ( 200w or more ) and these instructions:

http://www.wikihow.com/Convert-a-Computer-ATX-Power-Supply-to-a-Lab-Power-Supply


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## Just Cliff (Nov 27, 2008)

Thanks! Might have one of those about somewhere


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## Jim-mi (May 15, 2002)

Ahh . . no such thing as a DC transformer.........


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## idahodave (Jan 20, 2005)

Might not get the 14 [email protected] from a computer supply.


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## Birdman Jack (Feb 2, 2011)

Power supply from a computer will start smoking drawing that much amperage. You could run it off a battery. What does it run?


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## mightybooboo (Feb 10, 2004)

Is this it?

http://www.google.com/products/cata...irefox-a&cid=16403546719006166978&os=sellers#

or this?
-----------------------------
MAX BURTON 6993 15 AMP 200 WATT AC / DC 12 VOLT POWER CONVERTER
INSTANTLY CONVERTS 12 - VOLT APPLIANCES AND ACCESSORIES FOR USE WITH A STANDARD 120 VOLT OUTLET
WORKS WITH ALL BRANDS OF 12 VOLT PRODUCTS
POWER SWITCH ON THE CONVERTER WILL SHUT POWER OFF TO THE APPLIANCE

200 WATTS / 15 AMPS

120 VOLT AC INPUT

12 VOLT DC OUTPUT

LED INDICATOR LIGHT

MOUNTING BRACKETS

ETL LISTED
*

WEIGHT: 1.75 LBS
*

1 YEAR WARRANTY
*

DIMENSIONS: 8"L X 4.4"W X 2.6"H

http://compare.ebay.com/like/220682762164?ltyp=AllFixedPriceItemTypes&var=sbar


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## wy_white_wolf (Oct 14, 2004)

I salvaged an AC-DC convertor out of an old camp trailer for my setup. Steady 13.8VDC output to run 12VDC items when the batteries are low. Also works as a charger to bring the batteries up to about 80% charge. Handles 60A on the DC side and cost $5 and couple hours digging in the salvage yards.


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## MichaelK! (Oct 22, 2010)

TnAndy said:


> You need a power supply, not just a transformer, assuming you are coming from 120v AC to 12vDC.
> 
> Use the power supply out of a junk computer ( 200w or more ) and these instructions:
> 
> http://www.wikihow.com/Convert-a-Computer-ATX-Power-Supply-to-a-Lab-Power-Supply



Oh, thank you! I saved an old power supply, so now I know why. This will be a fun project to try!


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## TnAndy (Sep 15, 2005)

Dave and Jack:

Maybe I'm wrong....haven't tried it, but wouldn't a 250-300watt computer power supply be 250w / 12v = 20+ amps ?

Am I missing something ?


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## JohnP (Sep 1, 2010)

I've got a 200 watt PC power supply sitting here and it says 6 amp on the 12vdc output rating. Also, I wouldn't try pulling 14 amps through that small gauge wire. You can try here, http://www.powerstream.com/12-volt.htm
but I don't think you'll find anything "cheap" to do the job. When I was kid, I used to run a car cb radio in the house and radio shack made a 12vdc regulated power supply. It sold for $25 back in the 70s. Just checked their site and don't see them anymore. (they've turned into cellphone shack) An RV 12 volt power converter would work well. Inverter for going from 12vdc to 120vac, Converter for going from 120vac to 12vdc.


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## Just Cliff (Nov 27, 2008)

The Motor is on a 12v vacuum pump. It is not used in a continuous application. It will be turned on and off, maybe 20 to 30 seconds on then off. 

I do have one of the an old Clifford power supply that I use to test auto components. It isn't near stron enough. 
I didn't really want to run it off a battery. I wanted to keep it neat and clean. If worse came to worse I would definitly run it off a battery. Thats why I got a 12v. I had a 120vac and managed to screw it up three days from sunday.


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