Door Contactor Toggle Reed
Door contactor toggle trigger relay
Switching power supply maintenance can be divided into two steps:
In case of power failure, "see, smell, ask, and measure"
Look: Turn on the power supply enclosure and check if the fuse is blown. Then observe the internal conditions of the power supply. If you find that the PCB on the power supply has burned spots or broken components, you should check the components and related circuit components. asset Management
Smell: Smell the inside of the power supply for smells and check whether there are scorched components.
Q: Ask if the power supply has been damaged and whether the power supply has been violated.
Quantity: Before the power is turned on, use a multimeter to measure the voltage across the high voltage capacitor. If the switching power supply does not start to oscillate or an open-circuited switch causes a fault, in most cases, the voltage across the high-voltage filter capacitor is not discharged. This voltage is more than 300 volts. Be careful. Use a multimeter to measure the forward and reverse resistance of both ends of the AC power cord and capacitor charging. The resistance value should not be too low, otherwise there may be a short circuit inside the power supply. The capacitor should be able to charge and discharge. Disconnect the load and measure the resistance of the output of each group. When it is normal, the hand should have the capacitor charge and discharge swing, and the final indication should be the resistance of the bleeder resistance of the road.
After power-on, observe whether the power supply has burn-in insurance and smoke on individual components. If there is any problem, the power supply must be cut off for maintenance.
Measure whether there is 300 volt output at both ends of the high voltage filter capacitor. If not, check the rectifier diode and filter capacitor.
Measure whether the secondary coil of the high-frequency transformer has output, if it is not necessary to check whether the switch tube is damaged, whether it starts to vibrate, and whether the protection circuit operates, if any, check the rectifier diode, filter capacitor, and three-way stability of each output side. Pressure tube and so on.
If the power supply stops, the power supply can be directly measured and the voltage of the PWM chip protection input pin can be directly measured. If the voltage exceeds the specified value, the power supply is in the protection state, and the reason for the protection should be checked.