Maintenance method of bridge power supply circuit failure.

Last Update Time: 2019-04-27 15:32:59

Step 1. test whether the power supply circuit is burned or missing, whether the capacitor is bulging and leaking liquid, if there is any above phenomenon, replace it first.

Step 2. measure whether the bridge power supply to the ground is short-circuit, no short-circuit can be determined if the ground-to-ground value is not 0.

Step 3. measure the damage to the power supply MOS transistor.

Step 4. distinguishes the power supply mode of the power supply circuit.

Step 5. measure the working conditions according to the mode of power supply.

Operational amplifier + MOS tube: measurement of MOS tube D-pole power supply, G-pole control signal voltage, normal replacement of the MOS tube. No control signal check operational amplifier in-phase input signal and signal source.

Switching power supply: measurement of VCC, BOOT pin voltage should not be less than 5V according to the definition of power supply control chip pin, and whether the EN pin is higher than 0.4V voltage. Abnormal voltage check pin external resistance and control circuit.

Step 6. after normal working conditions, replace the control chip, output MOS transistor and filter capacitor.

This article is from Allicdata Electronics Limited.

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