Wannien 101v0 Power Supply Schematic
While a complete, official schematic for the Wannien 101V0 (E88653)
showing where these diagnostic LEDs would sit in the circuit? Wan Nien 101V0 Power Supply Schematic - Expert Q&A wannien 101v0 power supply schematic
- Primary overcurrent detection: sense resistor (Rshunt) or totem-pole sensing inside controller.
- Secondary overcurrent: foldback or hiccup implemented in controller or via TL431.
- Overvoltage protection (OVP) detecting excessive secondary voltage, often by clamping via zener or crowbar.
- Thermal protection: thermostat or built-in thermal shutdown in controller.
4. If you’re troubleshooting without a schematic
Use these steps:
: Small, low-power LEDs tied to each major voltage rail. A glance at the board would immediately reveal if a specific rail is dead, which is a major time-saver for repair technicians dealing with "no power" symptoms. Standardized Protection Circuitry : Enhanced over-voltage (OVP) short-circuit protection (SCP) While a complete, official schematic for the Wannien
- Observation: In many "Wannien" or generic 101v0 schematics, the input filter is minimal. You will often see a single fuse and perhaps one X-capacitor.
- Critique: There is frequently a missing Common Mode Choke (the toroidal inductor). This component is usually removed to save $0.05.
- Result: The power supply will work, but it will inject significant electrical noise back into your wall outlet. It will likely fail FCC/CE emissions testing. It makes the unit susceptible to damage from grid surges.
B. Output Voltage Fluctuating (5V–12V cycling)
- Check: TL494 Vcc (Pin 12). Should be stable ~15V. If jumping, the auxiliary winding diode or startup resistor (150k) has drifted high.
- Fix: Replace the 150k 2W startup resistor and the 47µF/50V cap near Pin 12.
