The switched high-voltage pulses are fed into the primary winding of a high-frequency ferrite-core transformer. This transformer serves two critical functions:

Two large electrolytic capacitors (typically 200V 680µF) smooth the DC. A 115V/230V selector switch determines if these capacitors act in series or as a voltage doubler. 2. The PWM Controller (The Brain)

A trimmer potentiometer is wired into this feedback divider, allowing users to tune the exact output voltage between roughly 10.8V and 13.2V. service manual - s-360-12 12v 30a power supply sch

Uses a current-sensing resistor (shunt) or current transformer to instantly drop the duty cycle to zero if a direct short is detected.

The TL494 controller IC monitors the 12V output and adjusts the pulse width (duty cycle) of the switching transistors to maintain a stable output voltage under varying loads. 3. Repairing and Troubleshooting the S-360-12

Converts AC input (typically 110V/220V) to high-voltage DC.

Look closely at the secondary side of the circuit diagram, and you will find a small variable resistor (potentiometer) labeled or V+ ADJ . This component tweaks the voltage divider feeding the TL431 reference chip. Turning this physical screw on the power supply casing allows users to safely calibrate the output voltage within a standard range of approximately 10.5V to 13.8V . Cooling Fan Control Circuit