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Old 03-02-2021, 10:09 PM   #2
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Default Re: An old dinosaur bench top power supply - help needed

The control is used to vary the ground of the 7805 so the output voltage will vary from +5v to something higher 12~20v
There looks like a burnt resistor above the switch? or is it just a black shadow?
Something like this: The component values are different but it shows the general idea of how it works.
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Last edited by R_J; 03-02-2021 at 10:15 PM..
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