Tips for repairing Tricycle Motorcycle chargers

Since the input circuit of the Tricycle Motorcycle charger works under the condition of high voltage and too much current, the failure rate is the highest. Such as high-voltage and high-current rectifier transistors, filter capacitors, switching power tubes, etc., and the rectifier diodes, protection diodes, filter capacitors, current-limiting resistors, etc. of the output rectifier part are more easily damaged, and then the feedback part of the pulse width modulation controller and Protection circuit part. In general, a blown fuse tube indicates that there is a short circuit or overcurrent fault in the internal circuit of the charger. This is due to the high failure rate of internal devices due to the high voltage and high current of the charger when it works for a long time. In addition, the fluctuation and surge of the grid voltage will cause the current in the Gasoline Tricycle charger to increase instantaneously and cause the fuse to blow.

First of all, carefully check the various components on the circuit board to see if the surface of these components is burnt or the electrolyte is overflowing, and smell-whether there is any difference. Then measure the resistance value of the input terminal of the power supply. If it is less than 20OkΩ, it means that there is a partial short circuit at the rear end. Then measure the positive and negative resistance values of the 4 rectifier diodes and the resistance values of the two current limiting resistors to see if there is a short circuit or burnt out. If there is still no above situation, then measure whether the input power line and output power line are short-circuited internally. In general, in the fuse blown fault, the rectifier diode, three-wheel motorcycle power supply filter capacitor, switching power tube, and UC3842 are vulnerable parts, and the probability of damage can reach more than 95%. It is very important to focus on checking these components. Easy to troubleshoot.
Finally, measure whether the filter capacitor of the Gasoline Tricycle power supply can be charged and discharged normally, whether the switching power tube is broken down and damaged, whether the UC3842 and surrounding components are broken down, burned out, etc. It should be noted that because of the on-road measurement, the measurement result may be wrong or cause misjudgment, so the components can be soldered down for measurement if necessary.