regulate 12 battery to 9 volt supply
This is a response to Mooneyguy on the "How to read mv output voltage" thread in the sensors forum, but it belongs here so as to not cross post or hijack the thread.
I made this simple circuit so long ago, I don't know where I got the design, but it has always been reliable for me for running anything in the car up to 4.5 amp draw. It has only 8 components.
You set the desired output voltage, anything less than 12 volts by adjusting the 5K mini pot. I usually have it set for 7.5 volts for a laptop computer.
Use (3) LM317T voltage regulators, each puts out 1.5 amps. Heat sink them well
I made this simple circuit so long ago, I don't know where I got the design, but it has always been reliable for me for running anything in the car up to 4.5 amp draw. It has only 8 components.
You set the desired output voltage, anything less than 12 volts by adjusting the 5K mini pot. I usually have it set for 7.5 volts for a laptop computer.
Use (3) LM317T voltage regulators, each puts out 1.5 amps. Heat sink them well
![voltage regulator.jpg](https://forums.parallax.com/uploads/attachments/65872/86218.jpg)
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That's probably not the best design to use. The reason is that the regulators' internal voltage references will vary by a little. With paralleled outputs, what will happen is that the loads will not be shared equally among the three regulators, with one of them supplying the bulk of the current, while the other two loaf.
BTW, in your schematic, the battery is reversed. The plus side gets the long bar; the minus side, the short one.
-Phil
By all means, welcome Lightfoot54! We certainly welcome and admire your enthusiasm and desire to help. My own posts often get "corrected" by heads much wiser than mine. It's both humbling and inspiring to be a part of this well-informed group. We all like to help out wherever we can. Keep up the good work and Merry Christmas!
erco