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Adjustable Voltage on PSU ATX Answered

I have an old Rockford P450.4 amplifier that I salvaged an LM317T and LM337T from. It also had some two (2) potentiometers that I salvages as well. I have a 400W Coolamx PSU ATX that I turned into a bench supply. I have read that people have been using these two (2) IC's to maintain a constant voltage through variable adjustment. I have seen several tutorials on instructables, but that all lack clarity, instruction and do not provide enough detail. I could really use a good tutorial, but have failed to find one of great interest.


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5 years ago

Where are you getting confused at? The basic schematic should give you all the information you need. There is a Voltage in, Adjustment and Voltage out pin on the LM317. Have the positive of the power supply connect to the Vin. Depending on the resistance of the POT will determine the resistor you wire in line with the pot. So you wire the POT from ground to the Adjustment pin. And then between the adjustment pin and the Pot your wire the resistor from there to the Vout pin. That's pretty much it. Just google LM317 and you'll find all the information you need.