Author Topic: 12 vdc wallwart  (Read 1495 times)

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bigdan

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12 vdc wallwart
« on: December 29, 2008, 07:14:33 AM »
I have a 16vac 4 amp wall wart.What do I do to convert the output to dc. Where do I place the diodes? Thanks in advance. Bigdan
« Last Edit: December 29, 2008, 07:14:33 AM by (unknown) »

Norm

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Re: 12 vdc wallwart
« Reply #1 on: December 29, 2008, 07:25:31 AM »
I'm just reading this post and observing....be nice

to have a few more details...what was it

originally for? and what do you plan to use the

thing for...a battery charger?...or to power a

12 volt device that needs how many watts to

operate it ?
« Last Edit: December 29, 2008, 07:25:31 AM by (unknown) »

CmeBREW

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Re: 12 vdc wallwart
« Reply #2 on: December 29, 2008, 03:25:24 PM »
Use a Full-wave Bridge rectifier like:


http://www.forcefieldmagnets.com/catalog/product_info.php?cPath=22_30&products_id=98


Simply hook the two AC lines to the two 'Wiggly' symbols (don't matter which way) on the Rectifier and the Positive is usually marked on it also-- and the negetive is diagonally across from the positive. Sometimes there is a 'Notch' out of one of the corners of the rectifier-- that is the positive.


But like Norm said, it would be nice to know what you are using it for because things like electronics likes to be more Regulated (pure and stable) DC than just a bridge rectifier.  


 

« Last Edit: December 29, 2008, 03:25:24 PM by (unknown) »

hiker

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Re: 12 vdc wallwart
« Reply #3 on: December 29, 2008, 10:45:28 PM »


« Last Edit: December 29, 2008, 10:45:28 PM by (unknown) »
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terry5732

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Re: 12 vdc wallwart
« Reply #4 on: December 30, 2008, 12:38:09 AM »
This is a typical bridge from a wall wart




The cap smooths the output some

« Last Edit: December 30, 2008, 12:38:09 AM by (unknown) »

CmeBREW

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Re: 12 vdc wallwart
« Reply #5 on: December 30, 2008, 07:21:42 PM »
Or you can make your own 'rectifier' (AC to DC) with 4 diodes like on the following page:


http://www.otherpower.com/rectifier.shtml


But they must be appropriate Amp capacity for whatever you are doing. And a DC capacitor (MF?) across the leads to smooth it out like Terry said would be better.  

But a pre-made rectifier is cheaper and better since you can hook it to a decent aluminum heat sink.  

BTW, Radio shack sells 25amp Rectifiers (but only upto 50v max) for only a few bucks each.

They work for simple projects. I'm using 3 of them on my Pedal generator screwed to a piece of aluminum. But I have no Capacitor hooked.

« Last Edit: December 30, 2008, 07:21:42 PM by (unknown) »