What is the working principle of a voltage regulator?
2 Answers
Voltage regulator working principle: Since the transmission ratio between the generator and the engine is fixed, the speed of the generator will vary with the engine speed. During vehicle operation, the engine speed varies over a wide range, causing the generator's terminal voltage to fluctuate significantly as well. Both power supply to electrical equipment and battery charging require stable voltage. To maintain the voltage at a constant level, it is necessary to regulate the generator's output voltage. The voltage regulator (abbreviated as AVR) is specifically designed for AC brushless generators equipped with fundamental/harmonic compound excitation or permanent magnet generator excitation (PGM system).
Since childhood, I've loved dismantling machinery. The voltage regulator in a car acts as the control brain of the generator. It senses voltage changes in the circuit, aiming to stabilize it around 14 volts. When engine speed variations cause power generation fluctuations, the regulator achieves balance by fine-tuning the generator's excitation current: reducing output to lower generation when voltage is too high, or increasing current to boost generation when voltage is too low. This prevents battery overcharging or component failures like burnt-out headlights, while also extending the generator's lifespan. Modern vehicles mostly use electronic regulators for more precise real-time monitoring; if it fails, you might notice flickering lights or a battery warning light. When repairing cars, I often remind friends that regularly testing the regulator can prevent unpleasant surprises, especially since maintaining an efficient electrical system is crucial during long-distance drives.
