Rotating RV1 changes the division ratio, adjusting output from ~1.2V to 36V.
The is a widely used industrial switching power supply (SMPS) designed to convert AC mains (110V/220V) into a regulated 12V DC output with a high current capacity of 30 Amps . Its internal architecture typically utilizes a half-bridge topology controlled by a TL494 PWM controller IC. Circuit Overview and Topology s36012 power supply circuit diagram