5V regulator gives 6.3 volts

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i have an L7805CV regulator and istead of taking out 5V it takes out 6.3V!, i have 15 of the same chips and all takes out the same. i am puting in 14V from a power suply but i also tried an input from a power supply.

i have some ideas but i would like to hear your thoughts.

Thanks and Regards, Ran.

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1. Is the ground pin connected properly?
2. Input and output decoupling capacitors?
3. Pin configuration? Read the data sheet. The 78L series have a different pin out from the TO220 types.

If you think education is expensive, try ignorance.

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i found the problem, it is my multimeter, i cheked with a fluke and it is 5V constant.

Thanks emuler for the response.

Regards, Ran.

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Run the multimeter over with your car!!

jim

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jgmdesign wrote:
Run the multimeter over with your car!!

jim

And after you do run that old meter over with your car, buy a good Fluke meter.

You can avoid reality, for a while.  But you can't avoid the consequences of reality! - C.W. Livingston

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I would try replacing the battery in the multimeter first. It is real easy to forget that they have a battery!

Might save you the cost of another multimeter.

Ross McKenzie ValuSoft Melbourne Australia

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valusoft wrote:
I would try replacing the battery in the multimeter first. It is real easy to forget that they have a battery!

Might save you the cost of another multimeter.

That's good advice. I know I was surprised the first time my Fluke starting giving incorrect readings and it only turned out to be the battery.

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Also open the case and look for a calibration potentiometer. I got half a dozen cheapies from Harbor Freight that were up to 15 percent off. For $4 I'd guess there wasn't much time to adjust each unit!

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ranc80 wrote:
i found the problem, it is my multimeter, i cheked with a fluke and it is 5V constant.

Thanks emuler for the response.

Regards, Ran.

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