: The mechanical selector toggle configures two large bulk electrolytic filtering capacitors (typically rated at 200V,
(Inductors and Capacitors) ensure a clean 12V output with minimal ripple. Feedback & Regulation:
On the secondary side of the transformer, the low-voltage high-frequency AC is rectified by a set of , which are chosen for their very low forward voltage drop and fast switching speed, leading to high efficiency. This rectification turns the AC pulses into a pulsating DC. This is then passed through an LC filter , consisting of a series inductor (coil) and parallel output capacitors, to smooth the voltage. This filter is responsible for reducing the output voltage ripple to a maximum of just 150mV peak-to-peak, ensuring a clean DC supply for sensitive electronics. s36012 power supply circuit diagram
Limits the "inrush current" when you first flip the switch.
Because the switching frequency is incredibly high, the main step-down transformer can be physically small compared to traditional 50/60 Hz mains transformers. It provides galvanic isolation between the lethal high-voltage primary AC side and the safe low-voltage secondary DC side. 5. Secondary Output Rectification and Filtering : The mechanical selector toggle configures two large
An (inductors and X/Y capacitors) prevents high-frequency noise from feeding back into the mains. Rectification & Bulk Filtering:
Often caused by a blown fuse, failed NTC thermistor, or shorted switching transistors. This is then passed through an LC filter
The switched pulses from the MOSFET are then applied to the primary winding of a specially designed high-frequency power transformer. Unlike bulky, low-frequency transformers, this ferrite-core transformer is compact and highly efficient. It performs two critical functions: it steps down the high-voltage pulses to a much lower voltage (around 12V AC) and, most importantly, it provides between the dangerous high-voltage primary side and the safe, low-voltage output. This isolation is a vital safety feature.
When set to 220V, the bridge rectifier acts conventionally. When flipped to 110V, the switch alters the circuit trace into a voltage doubler network utilizing two massive high-voltage electrolytic capacitors, ensuring a stable DC bus across both configurations. 3. Half-Bridge Inverter Stage
Suppresses high-voltage transient spikes from the AC grid.
: Dual Pi-filters, consisting of safety X/Y capacitors and a dual-winding common-mode choke coil, prevent high-frequency switching noise from feeding back into your household mains grid. 2. Primary Rectification and Voltage Selection