What is the structural principle of a motorcycle charging system?

[StSamantha]

There are three structural principles of a motorcycle charging system: AC charging and AV charging. AC charging: After inserting the charging gun into the vehicle's charging port, the detection point can detect that the 12V voltage passes through RC and the S3 switch to ground. At this point, the voltage at the detection point is no longer 12V, and the vehicle can detect through detection point 3 that the charging gun has been inserted into the port. The R4 resistor is used to check whether the charging gun is fully inserted. If it is not fully inserted, the switch (located on the charging gun) opens, and the resistor is connected in series into the circuit, allowing the charger to be informed via the detection point. Additionally, the voltage detected at detection point 3 can determine the RC resistance value, thereby identifying the charging gun model. After the charging gun is inserted into the vehicle's charging port, the 12V voltage passes through S1 and R1, reaching detection points 1 and 2 in sequence, and then grounding through R3 to complete the circuit. At this point, the voltage at detection points 1 and 2 is no longer 12V. Due to the voltage division by R1=1000 ohms and R3=3000 ohms, the detection point voltage is 9V. When a voltage of 9V is detected, the S1 switch changes from 12V to a PWM signal connection. At this point, detection points 1 and 2 will display a duty cycle signal that changes from 9V to -12V, confirming the charging gun connection. Then, the S2 switch closes to provide feedback to the charging equipment. After S2 closes, R1 (in series), R2, and R3 (parallel resistors, R2=1500 ohms, parallel resistance value of 1000 ohms) are added to the circuit, changing the circuit voltage from 9V to 6V. At this point, the charger can approve charging. AV charging: When the power plug is inserted into the power supply equipment, the PWM inputs a low level. At the same time, the 5V voltage completes the circuit, causing the photodiode to emit light, and the 12V voltage circuit is connected, providing a forward bias voltage to T1. The 12.5V above passes through T1's collector and emitter, outputting to CP. The voltage on the CP output side is a 12V high level.

[VanMariana]

I've been riding motorcycles for ten years, and only recently learned about its structure when the charging system had issues. The motorcycle charging system mainly relies on the magneto to generate electricity, which is a small device driven by the engine rotation. It contains magnets and coils, producing electricity when the engine runs. However, this electricity is AC (alternating current) and cannot directly charge the battery, so it is converted into DC (direct current) through a rectifier. A voltage regulator then controls the voltage to ensure the battery doesn't get damaged. Finally, the electricity is stored in the battery for starting the engine and powering the lights. My issue back then was due to a faulty rectifier, which prevented the battery from charging, causing the headlight to suddenly go out at night—very dangerous. For regular maintenance, I often check if the wiring and connectors are loose. After riding in the rain, I make sure to dry the electrical components. Periodically testing the battery voltage to ensure it stays around 12 volts is sufficient. Don’t underestimate this system—without it, the battery can die during long rides, and pushing the bike is exhausting. I recommend beginners always carry spare fuses.