12V Switched-mode Power Supply Reverse-Engineered, Modified for 5-15V Variable Output with Voltmeter Display
This video – and accompanying blog post – by Lindsay Wilson is impressive. In it he shows and explains the steps for modifying a SMPS to deliver variable voltage, with an extensive analysis of the power supply circuit, along with reverse-engineering the PCB, removing native components, adding a new feedback divider, fitting a voltmeter display onto the supply chassis, and more.
I’ve taken a 12V 33A power supply and modified the feedback network to provide a fully adjustable 5-15V. I’ve also traced out the entire schematic. A full description of operation and details of the modification are available on my website at the link below.