Tricycle With Cabin charger repair

Since the input circuit of the Tricycle With Cabin charger operates at high voltage and excessive current, it has the highest failure rate. Such as high-voltage and high-current rectifier transistors, filter capacitors, switching power tubes, etc.; secondly, the more easily damaged are the rectifier diodes, protection diodes, filter capacitors, current-limiting resistors, etc. of the output rectification part; and then there are the feedback part and the pulse width modulation controller. Protection circuit part.

Generally speaking, 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 under high voltage and high current conditions for a long time, and the failure rate of internal components is high. In addition, fluctuations in grid voltage and surges will cause the current in the charger to increase instantaneously and cause the fuse to blow.
First, carefully check each component on the circuit board to see if the surface of these components is burnt or if there is electrolyte spillage, and if there is anything strange about the smell. Then measure the resistance value at the input end of the power supply. If it is less than 20OkΩ, it means there is a partial short circuit at the back end. Then measure the forward and reverse resistance values of the four rectifier diodes and the resistance values of the two current limiting resistors to see if there is any short circuit or burnout. ; If the above situation still does not exist, measure whether the input power line and output power line are internally short-circuited. Generally speaking, when a fuse blows out, the rectifier diode, power filter capacitor, switching power tube, and UC3842 are wearing parts, and the probability of damage can reach more than 95%. It is easy to troubleshoot these components by focusing on checking them.
Finally, measure whether the power supply filter capacitor 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 or burned out, etc. It should be noted that because it is measured on the road, the measurement results may be incorrect or misjudgment may occur. Therefore, the components can be soldered down for measurement if necessary.