+--------------------+ | HT2812H | | | +-----------+---HV VCC---+---> To VCC Supply | | | | | | Pri. Winding | | of Transformer | | | | | +-----------+CS FB---<-----+ From Aux. Winding | | +---CS (Sense) | | | [Rcs] | | | GND | (Primary GND) | | +-------------------+ | | Secondary Side | (Isolated Output) | +-------------+-------------+ | | | +-------+ | +---+D1 (Schottky)+-----> +5V Out | +-------+ | | | | | +-------------------+ | | | +----------+ | +---+C1 (390µF)+---+ | | +----------+ | | | | | | | +---L1 (Inductor) | | | | | +----------+ | +-------+C2 (Cap)+----+ | +----------+ | | | | | GND GND GND (Secondary GND) | | AC Input | | | +--+---+ | | F1 | | +--+---+ | | | +-----+-----+ | | MOV EMI | | | (Varistor)| | +-----+-----+ | | | +-----+-----+ | | Bridge | | | Rectifier | | | (MB10F) | | +-----+-----+ | | | +-----+-----+ | | Bulk Cap | | | (Filter) | | +-----+-----+ | | | +-----+-----+ | | Snubber | | | Network | | +-----+-----+ | | | +-------------------------+ | | | +-----------------+ | Primary Winding of Transformer | To HV Pin of IC
: Maintain a mandatory safety gap of at least 6mm between high-voltage AC primary traces and low-voltage DC secondary traces. Do not run any copper traces underneath the isolation transformer body.
Usually a 4.7µF 400V electrolytic capacitor that smooths the rectified DC. The Controller IC:
Observe proper safety rules: Never probe or measure the high-voltage primary side of an active WX-DC12003 circuit without using a dedicated isolation transformer on your oscilloscope. Share public link wxdc12003 schematic better
: Add a secondary 100µF low-ESR capacitor on the clean side of the inductor to establish a pristine DC voltage supply rail. 3. Integrate Modern CAD Models
A bridge rectifier converts AC to raw high-voltage DC ( 170V170 cap V 380V380 cap V DC, depending on input voltage).
The included thermistor might be insufficient, leading to blown fuses or tripped breakers on startup. Do not run any copper traces underneath the
Uses a compact high-frequency transformer to provide galvanic isolation between the high-voltage AC input and the low-voltage DC output. Output Section:
: The 5V output lines carry up to 700mA. Keep those paths short and use copper trace widths of at least 0.8mm (approx. 30 mils) to minimize impedance and prevent voltage drops.
In conclusion, the claim that the "WXDC12003 schematic is better" is not merely subjective preference; it is an objective assessment of engineering quality. By enforcing a logical signal flow, embedding design-for-testability features, and meticulously separating power and analog domains, this schematic serves as a benchmark for power supply design. For the junior engineer, it is a masterclass in best practices; for the seasoned professional, it is a reliable template that reduces risk and shortens development time. Ultimately, a better schematic does not just describe a circuit—it elevates the final product, and the WXDC12003 does exactly that. Share public link : Add a secondary 100µF
Lack of proper output filtering can introduce switching noise into sensitive electronics, such as microcontrollers or audio circuits. Output Ripple: The 12V12 cap V rail can have excessive ripple ( ), affecting ADC measurements or sensor data stability.
This public link is valid for 7 days and shares a thread, including any personal information you added. This link or copies made by others cannot be deleted. If you share with third parties, their policies apply. Can’t copy the link right now. Try again later. 85~265V AC to 5V 3.5W DC Isolated Power Supply Module
: You can find a dedicated WX-DC12003 KiCad library on GitHub , which includes footprints and 3D models for PCB design.
: Research on All About Circuits indicates at least two distinct versions: the original WX-DC12003 and the JL-AD3W-HT-V3 .