Yp-05 Schematic

Almost every Yp-05 schematic terminates with:

| Reference | Typical Value | Function | Failure Indicator | | :--- | :--- | :--- | :--- | | F1 | 2A – 5A 250V | Protection | Open circuit (no continuity) | | RT1 | 5D-11 | Inrush limit | Cracked, high resistance (>50Ω) | | C1 | 100µF/400V | Bulk storage | Bulging top, low capacitance | | Rstart | 150k-300k | Startup | Open circuit (no P_IC VCC) | | Q1 | 600V N-MOSFET | Switching | Shorted G-D-S | | U1 | UC3844 | PWM control | No oscillation on pin 6 (Gate) | | U2 | PC817 | Feedback | Low CTR (output can’t pull low) | | D5, D6 | UF4007 | Rectification | Shorted or open | | U4 | 7815/7824 | Linear reg | Input voltage present, output zero |

(This section should be populated based on the specific header labels on the schematic) Yp-05 Schematic

| Pin Number | Function | Voltage/Logic Level | | :--- | :--- | :--- | | 1 | VCC_In | 12V | | 2 | GND | 0V | | 3 | Data_Out | 3.3V Logic | | 4 | Control_In | 3.3V Logic |

Post-inductor, the Yp-05 schematic includes: Almost every Yp-05 schematic terminates with:

This is where most users modify the Yp-05 for custom voltages. The output voltage is set by:

VOUT = 0.8V (for newer ICs) or 1.25V (for XL4015) × (1 + R2 / R1)

On the Yp-05 schematic, you will see:

Mod tip: Replace R2 with a 20kΩ potentiometer (trimpot) for an adjustable 1.5V – 28V output. Just be careful not to exceed the 5A current limit.

The designation “YP-05” most often refers to a power supply or driver board found in certain audio amplifiers (notably some vintage Japanese integrated amps) or, less commonly, a prototyping/development board for a specific IC. If you have a specific device (e.g., Yamaha, Sony, or a DIY project), clarify for a more tailored guide. | Reference | Typical Value | Function |

Assuming the common case of a power supply/regulator or protection circuit (YP-05 as a PCB assembly), here’s what to look for on the schematic:

Modify the Yp-05 schematic by adding an OP-amp (e.g., LM358) that senses voltage across a 0.1Ω shunt resistor on the output low side. Feed that voltage into the FB pin, overriding voltage control. You now have a 5A constant-current LED driver.