The WLX-896B is a multi-port USB smart charger (often branded under names like Sunshine, Mechanic, or Wylie) known for its integrated LCD display that monitors real-time charging metrics. Circuit Overview & Schematic Logic
The device functions as a Switching Mode Power Supply (SMPS) designed to convert AC mains (100–240V) into a stable 5V DC output. Its schematic typically consists of three primary functional blocks: AC Input & Rectification:
Protection: Includes a fuse, NTC thermistor (for inrush current protection), and a filter (EMI/X capacitors and common-mode chokes) to prevent interference.
Rectifier: A bridge rectifier converts AC to high-voltage DC, smoothed by a primary bulk electrolytic capacitor. DC-DC Conversion (Primary Side):
PWM Controller: A high-speed switching IC (often an All-in-One PWM chip) drives a power MOSFET to pulse energy through the high-frequency transformer. wlx896b schematic work
Feedback Loop: Uses an optocoupler and a TL431 precision reference to monitor output voltage and adjust the PWM duty cycle for stability. Output & Monitoring (Secondary Side):
Synchronous Rectification: Uses diodes or MOSFETs to rectify the transformer's output to 5V DC.
Current Sensing: Each USB port often has a low-resistance shunt resistor (e.g., 0.1 ohm) in the ground path to measure the current draw of individual devices.
LCD Controller: An onboard microcontroller (MCU) reads these shunt voltages, calculates the wattage, and displays it on the LCD screen. Key Specifications Input: AC 100-240V, 50-60Hz. The WLX-896B is a multi-port USB smart charger
Total Power: Typically rated at 40W to 87W depending on the specific "B", "+", or "P" sub-model.
USB Output: Standard 5V ports (up to 2.4A or 3.5A each) and often one QC 3.0 (Quick Charge) port that can negotiate 5V/9V/12V. Common Faults & Repair Tips
Pulsing Display: Often caused by a short circuit on the secondary side (e.g., a shorted Schottky diode) or a failing feedback optocoupler, causing the PWM chip to enter "hiccup mode".
No Power: Usually a blown input fuse or a failed primary MOSFET. Always check the main bulk capacitor for charge before handling. Locate the feedback resistor divider on your schematic
Inaccurate Readouts: This is often due to tolerances in the shunt resistors or the MCU's internal calibration.
For detailed visual layouts, users often refer to Sunshine SS-304Q or Mechanic V-Power documentation, as they share nearly identical board designs with the WLX-896 series.
Are you troubleshooting a specific component failure or looking for a component-level layout of the PCB? Fixing a faulty USB power supply.
Based on the typical hardware configuration for devices utilizing the WLX896B model number (commonly associated with Winstars display modules or similar Wi-Fi/IO controller boards), here is the operational schematic description and technical work text:
With your multimeter in continuity mode, find the input connector (e.g., VIN+ and GND). Follow the thick copper traces:
The feedback network determines output voltage. Find the trace from VOUT+ going through a resistor divider (two resistors in series) to ground. The middle point connects to the controller’s FB (feedback) pin.
Vout = Vref * (1 + R_top / R_bottom).