12 to 8VDC Converter


Thread Starter


Need a simple diagram for 12 to 8 VDC Converter for 10 w power consumption, No heat !!



You can easily build such a supply using the "Simple Switcher" chips available from National, Linear Tech, Maxim, and a number of other manufacturers. If you only need to build one, you should be able to find an evaluation board that will do what you want.


Willy Smith
A simple voltage divider will work, that is if you can find 10W resistors, another thought is a 2/3 gain opamp circuit.

Curt Wuollet

For little heat, a switcher is your only option. Anything linear or passive will generate heat. Check with the IC manufacturers they make chips that with a few reactive components will do what you want with high efficiency. You could do this with a 555 and an inductor and clever circuitry, but the chips have better specs and aren't very expensive, they make it simple because they are dedicated to that purpose. These small switchers are used a lot for handhelds and other battery operated stuff.


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> For little heat, a switcher is your only option.

Be careful to smooth it, though - the DV camera may or may not like dirty power...

> Anything linear or passive will generate heat.

Yup; and it'll also run the output voltage down as the battery runs down; a car battery is 12V nominal, but it gets charged at 13-14V when the engine is running, and can run down to 10-11V easily.

If you're not going to be using the battery for starting the car, make sure you get the right kind of battery, otherwise it'll die fairly quickly.

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