The is one of the most ubiquitous industrial switching power supplies on the market. Rated for 12V DC at 30A (360 Watts) , it is the "workhorse" for 3D printers (like the Creality Ender series), CCTV systems, and amateur radio setups.

Usually a pair of 13009 NPN power transistors. These turn the high-voltage DC into a high-frequency AC signal (usually 50kHz–100kHz).

Usually two large 470µF or 680µF electrolytic capacitors that smooth the ripple. 2. The PWM Controller (The Brain)

An output inductor (toroidal coil) and several low-ESR capacitors smooth the final DC output to minimize "ripple voltage." Critical Component Values for Repair

It monitors the output voltage and adjusts the "width" of the pulses to ensure the output stays at a steady 12V, regardless of whether you are drawing 1 Amp or 30 Amps. 3. Switching & Transformation