Motorcycle battery charger circuit diagram

The 555 time base circuit and external resistors, capacitors and potentiometers form a thyristor trigger circuit. It is actually an astable multivibrator. After the power is turned on, C1 and C2 are charged at the same time, and the potential of pin 5 of 555 quickly rises to 2/3Vcc. At this time, the voltage on C1 is about zero, that is, the voltage of pins 2 and 6 is slightly greater than 2/3Vcc, and the output terminal 3 pin is low. The discharge tube inside the 555 is saturated, that is, pin 7 is low level, so C1 discharges, causing the potential of pins 2 and 6 to gradually drop to 1/3Vcc, and pin 3 outputs high level. This forms an oscillation, and the output of pin 3 controls the charging of the thyristor. W can adjust the charging current. When a short circuit occurs at the charging terminal, T1 is saturated, LED2 light-emitting tube lights up, the voltage at pin 4 of the forced reset terminal of 555 is approximately zero, and the trigger circuit is closed.