Official schematics are rarely public. However, you have three viable paths:
Warning: Avoid scam "schematic download" sites asking for credit cards. Legitimate schematics are shared freely in repair communities.
The A20112 power supply schematic is a textbook example of a flyback converter with primary-side PWM control and secondary-side TL431 regulation. Whether you are repairing a dead monitor or designing a custom 12V power source, understanding this schematic gives you a massive advantage.
Key takeaways:
Final advice: Download a generic UC3842 flyback reference design from Texas Instruments; it will match 90% of the A20112’s topology. Then, adapt based on your specific board’s component callouts. a20112 power supply schematic
If you have a specific A20112 variant or an unusual failure, post clear photos of both sides of the PCB on electronics repair forums – with the knowledge from this guide, the community will help you map out the exact schematic.
Repair safely – always discharge the bulk capacitor (310V DC) with a 10kΩ resistor before probing.
The "A20112" identifier is most commonly associated with a 12V 10A (120W) switching power supply board often found in DIY 3D printers, CCTV systems, and universal AC-to-DC converters . The "Story" of the A20112 Power Supply
In the world of hobbyist electronics and repair, the A20112 serves as a "workhorse" component. It is frequently the core power unit for devices like the Tronxy X-3 and FLSun i3 clone 3D printers . Official schematics are rarely public
The Component's Journey: Unlike proprietary power bricks, the A20112 is a bare-board or aluminum-cased switching mode power supply (SMPS) designed for integration into larger projects . It is prized for its 120W capacity, allowing it to handle high-power demands—like heating a 3D printer's bed or running multiple security cameras—without failing .
The Schematic Context: While a specific "A20112" schematic is often sought by repair enthusiasts looking for "PCB0100B-V07" board layouts , its design follows the standard SMPS anatomy:
Input Filtering: Protects the circuit from power line spikes .
Rectification: Converts AC mains voltage to high-voltage DC . Warning: Avoid scam "schematic download" sites asking for
High-Frequency Switching: Uses a transistor to "chop" the DC into high-frequency AC for efficient transformation .
Final Rectification & Filtering: Outputs a stable 12V DC signal . Key Technical Specifications Output Voltage Output Current Total Power Enclosure Typically an aluminum "mesh" case for cooling Common Uses 3D Printers, CCTV Monitor Systems, LED Strips Common Identification Errors
If you are searching for this part, be aware that "A20112" is also used for unrelated items in different industries: Switching Power Supply Technical Manual - ADM and MEAN WELL
However, I can offer some general guidance on how to find or work with power supply schematics:
Insert a low-value sense resistor on the output return path and use an op-amp to feed back into the optocoupler. Refer to the schematic’s primary-side current sensing as a model.
The A20112 is a switch-mode power supply (SMPS) designed for the Namco System 246 and 256 arcade motherboards. Unlike standard PC ATX power supplies, the A20112 utilizes a custom form factor and a dedicated single-row output connector to interface directly with the arcade I/O board. It is a high-efficiency unit capable of delivering substantial current on the +12V rail to power the console's cooling fans and disc drives, while maintaining stable low-ripple voltage for the sensitive CPU and RAM (+3.3V and +5V).