Yh-305d Power Supply Schematic -

Based on technical discussions and teardowns at the EEVblog Forum and Scribd , key parts include:

: An L7805CV is often used to provide a stable 5V rail for the digital display and microcontroller.

: Upgrading the internal cooling fan for quieter or more efficient operation. Yh-305d Power Supply Schematic

: Precision operational amplifiers compare the output voltage and current against the levels set by the front-panel potentiometers, adjusting the pass transistors to maintain a Constant Voltage (CV) or Constant Current (CC) state. Common Components in the Schematic

: The final regulation is handled by high-power pass transistors (often 2N3055 or equivalents) mounted on a large internal heatsink. Based on technical discussions and teardowns at the

: To minimize heat dissipation across the pass transistors, the circuit uses relays that switch between different transformer taps at specific voltage thresholds (e.g., 8V, 16V, and 24V).

The YH-305D's narrative includes frequent user reports of quality control issues, particularly with overheating. Many hobbyists choose to modify their units by: Common Components in the Schematic : The final

: A low-resistance shunt resistor is used to measure current, with adjustment trimmers (like VR10 for offset and VR11 for gain) allowing for calibration.