Will the flyback diode circuit formed when the relay opens damage the power supply? 2

The function of a freewheeling diode is essentially to transfer the energy generated in the relay to other circuits to prevent damage. When the current in the inductive component decreases and induces a reverse voltage, the freewheeling diode conducts to release this energy into other circuits. Since the freewheeling diode is reverse-polarity, it only conducts under reverse voltage conditions and not during normal operation.

Now let's discuss the topic: Could the freewheeling diode circuit formed when the relay opens damage the power supply?diode

The answer is no. The circuit formed by the freewheeling diode is a closed local loop, primarily serving to provide a path for the induced current in the FQD4P40TM relay coil to dissipate. The current in this loop is driven by the induced electromotive force generated within the relay coil, not by the power supply. Therefore, the current in the freewheeling circuit does not flow back into the power supply and thus poses no damage to it.

In fact, using a flyback diode not only does not damage the power supply but also serves as a protective measure. Without a flyback diode, the back electromotive force may generate unpredictable high-voltage pulses through the power supply circuit, posing a potential risk to both the power supply and the entire circuit system. The flyback diode mitigates this risk by providing a safe discharge path.diode

In summary, the freewheeling diode circuit formed when the relay opens is a crucial and effective protective measure. By providing a closed local loop to dissipate the inductive current in the coil, it prevents arcs and voltage spikes caused by high back EMF, thereby protecting components in the circuit, including the power supply. Therefore, using a freewheeling diode does not damage the power supply but rather serves as a protective measure for it.diode