Restore Switch Excitation Circuit in Power Supply PCB Card can greatly increase the efficiency of medical instrument PCB board troubleshooting;
The switch tube, the positive feedback loop and the switching transformer can form a self-excited switch. This switching power supply is prone to malfunction in the capacitance and resistance existing on the positive feedback loop during device operation.
The logic processor, oscillator, and amplifier together form an excited switching power supply. The specific implementation of the control process depends on the integrated circuit, and some circuits require a monolithic thick film integrated block. This implementation method causes a high probability of failure of the switch tube .
At present, most of the switch tubes include N-channel high-power field effect transistors. During the fault controller board troubleshooting process, the quality of the N-channel high-power field effect transistors should be clarified, so that the power supply can be repaired well.
Voltage output circuit
The circuit formed by the secondary of the switching transformer after high-frequency diode and capacitor filtering is called a voltage output circuit. The faults that are likely to occur in the voltage output circuit are mainly the filter capacitor and the current limiting resistors in different parts
