TL494 switching power supply module

This project is used to verify the solution verification board design of the Lichuang Mall switching power supply chip TL494CDR (product number: C19882, etc.).

This verification board is the switching power supply module of TL494. The E1 and E2 pins of the chip jointly drive the IRF540 to turn on and pinch off the input voltage. The inductor and capacitor form a Buck topology with the MOS tube.

** Feedback method: **

1. Voltage feedback: divide the voltage with a potentiometer and a 1k resistor, input the feedback voltage into IN1+, and adjust the voltage through the potentiometer;

2. Current feedback: Convert to constant current mode through relay, but the feedback voltage is 0.5 times the current value.

** control method: **

The external resistors and capacitors of PT and CT determine the switching frequency of the PWM wave, and the output duty cycle can be controlled through the external input reference voltage.

** Current limiting protection: **

The feedback current can be collected through AD, and when the current exceeds the set value, the relay is controlled to shut down the circuit.