Energy-saving motorcycle rectifier regulator circuit

　　The circuit of this device is shown in the figure. The AC voltage output by the magneto is rectified by diodes D1~D6 and becomes a pulsating DC voltage, which is output in two ways. One way is a typical transistor series voltage regulator circuit composed of Q1, Q2, Q3, R1, R7, DW1, and C2, and then outputs a 16V voltage after voltage regulation, which is used to charge the battery through D8; the other way is isolated by D7, filtered by C1, and regulated by IC1 to obtain a 12V DC stable voltage to power the operational amplifier IC2, and connected to the ② pin of IC2 through resistor R6 as a reference voltage. The battery voltage is divided by R4 and R5 and sent to the ③ pin of IC2 as a comparison voltage. When the battery voltage is lower than 14.4V, the comparison voltage added to the ③ pin of IC2 is lower than the 12V reference voltage of the ② pin, the operational amplifier outputs a low level, Q4 is cut off, and Q1~Q3 work normally and output 16V voltage. When the battery voltage is higher than 14.4V, the comparison voltage of IC2's pin 3 is higher than the reference voltage of pin 2, IC2 outputs a high level, Q4 is saturated and turned on, shunting the current flowing into the base of Q3, causing the output voltage of Q1Q2 to drop significantly, D8 is cut off, and the battery charging and electrical power supply to the appliance are stopped. At this time, all the electrical appliances in the car are powered by the battery. When the battery voltage is lower than 14.4V again, IC2 outputs a low level again, and Q1 and Q2 output normally again. Obviously, when the battery is fully charged, the magneto works almost in a no-load state, unlike the conventional silicon rectifier regulator, which is in a large load short-circuit state, thus achieving the purpose of energy saving. In the circuit, R3 is the positive feedback resistor of IC2, R7 is used to trickle charge the battery when Q1Q2 is cut off, and the role of D9 is to ensure that the slight zero drift output of some operational amplifiers will not cause Q4 to turn on and cause malfunction.