Voltage Regulator 7812a - 12v [Archive] - Duramax Diesels Forum


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03-30-2008, 10:02 PM
I thought this would drive a sensor at 12v.

Yes and no. If truck volts fall below 12.9, the output voltage of the regulator drops. Why is this important? It is normal for your truck to be at 12.5v with the key on but not running. So the guage will not read right until you start it. It will be at 11.5v to the gauge.

From 13.0 to 19.0 volts it works VERY well. Keeps 12.0 steady as a rock with little "noise". Your truck is about 14.5v when running.

These are available at Radio Shack.

With writing facing you, and leads down:

Left lead is input voltage positive (truck battery)
Center is ground (truck battery)
Right is 12.0v for feeding a gauge. Use same ground as center.

04-04-2008, 03:05 PM
If you are looking for a solution to work at a broader input voltage look for a DC-DC converter. There are many types available, you just need to define input voltage range, output voltage and power.
Here is a link: