Re: Correcting the Voltage on a Power Supply


Blair
 

You cannot provide a constant voltage drop for a varying current using a
resistor.
Best approach would be to put a few (nominally, 3) diodes in series with
the positive leg of the supply.. With a voltage drop of 0.6 V each, you
should have just about 12 V.

But. Make sure the diodes are rated for the full output of the supply.
If it's a 3 Ampere supply, use at least 3 Amp diodes.

Regarding the brick, what don't you know? Generally, they're constant
voltage, variable current supplies in the 16-20 volt range. They
usually have a rating on the ID sticker.
What do you want to use it for?
Blair Smith

On 07/07/2012 4:43 PM, Eric wrote:
I recently bought a used Tripp-Lite power supply at a trin show. It was listed at 12 vdc, but when measured with a volt meter, it is actually putting out 13.7 vdc. Since my Tortoise switch machines require NGT 12 vdc, what sized resistor should I use in my supply connection to the power distribution block to reduce the voltage? Or how do I go about reducing the voltage to a desired level?

A second question is how to use a laptop computer "brick" as a Power Supply?

RicZ



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