Power Strip Manufacturer | Principle and method of LCD power board repair

Power Strip Manufacturer | Tell me about the principle of LCD TV power supply maintenance and some maintenance methods

The main components of the circuit

1. Incoming filter circuit This circuit is that the AC 220v voltage is filtered by several capacitors and inductances through the insurance, varistor, and the interference wave in the AC power is filtered out, also commonly known as the anti-interference circuit.

2. Rectifier and filter circuit This circuit uses the 220v voltage sent by the incoming filter circuit to rectify the 280-320v DC voltage through the rectifier bridge and store it in the large filter capacitor.

3. The auxiliary power circuit is composed of a power management chip, a switch tube and a transformer, and generates a standby voltage of +5vsb during operation.

4. PFC circuit PFC circuit is also known as power factor correction circuit; its function is to improve the efficiency of power utilization; after the second boot, the auxiliary power supply is the drive control circuit of the pfc circuit, which increases the 280v voltage to about 380v and improves the load capacity of the power supply .

5. Main power supply circuit After booting, the secondary power supply also provides vcc-on power supply for the main power supply drive sawtooth circuit, the main power supply starts to work, and the secondary output provides +24v and +12v voltages to the main board load circuit.

6. Voltage stabilizer circuit and overcurrent and overvoltage protection circuit These two circuits are mainly to stabilize the voltage output by the switch machine (mainly composed of stabilizer diodes, etc., generally there are several) and overcurrent and overvoltage at the output (mainly composed of optocouplers). and other components, through the optocoupler feedback signal), feedback information to the chip to make it stop working and turn off the output (which also plays a protective role).