Electric car chargers often burn input insurance because:
Under normal circumstances, a blown fuse tube indicates that there is a short circuit or overcurrent fault in the charger's internal circuit. This is because the charger works in the state of high voltage and high current for a long time, and the failure rate of the internal components is high. In addition, the fluctuation of power grid voltage and surge will cause the current in the charger to increase instantaneously and blow the fuse.
maintenance methods
1, first carefully look at the various components on the circuit board to see whether the appearance of these components is burned or there is electrolyte overflow, smell - smell no ambiguity.
2, then measure the resistance value of the power input, if less than 20OkΩ, it indicates that there is a local short circuit phenomenon at the back end, and then measure the positive and negative resistance value of the 4 rectifier diodes and the resistance value of the two current limiting resistors to see whether there is a short circuit or burned out; Finally, measure whether the power filter capacitor can be charged and discharged normally, whether the switching power tube is broken down and damaged, whether UC3842 and the surrounding components are broken down and burned out.