In a relay, a flyback diode is used to protect the circuit from voltage spikes that occur when the relay coil is de-energized. When the relay coil is energized, it creates a magnetic field that pulls the relay contacts closed. When the coil is de-energized, this magnetic field collapses suddenly, inducing a high voltage spike in the opposite polarity across the coil terminals. This spike can potentially damage sensitive electronic components in the circuit, such as transistors or microcontrollers. The flyback diode, also known as a freewheeling diode, provides a path for this induced voltage spike to dissipate harmlessly, protecting the rest of the circuitry from damage.
The primary purpose of a flyback diode in a relay circuit is to suppress the voltage spike that occurs when the relay coil is de-energized. When the relay coil is energized, it builds up a magnetic field. When the coil is suddenly de-energized, the collapsing magnetic field induces a voltage spike of reversed polarity across the coil terminals. This spike can reach high voltages and potentially damage semiconductor components in the circuit. By placing a flyback diode across the relay coil terminals in reverse bias, the diode conducts when the voltage spike occurs, providing a path for the current to circulate and dissipate the energy safely. This protects the rest of the circuit from the harmful effects of the spike.
The purpose of a flywheel diode, also known as a freewheeling diode or a snubber diode, is to protect electronic circuits from voltage spikes and transient voltage surges generated by inductive loads. When inductive loads, such as relays, solenoids, or motors, are switched off, they generate high-voltage spikes due to the sudden collapse of the magnetic field around them. These spikes can damage semiconductor devices in the circuit by exceeding their voltage ratings. A flywheel diode is placed in parallel with the inductive load in reverse bias. It conducts when the voltage spike occurs, providing a path for the current to circulate and dissipate the energy harmlessly. This protects the rest of the circuit components from the damaging effects of the voltage spike.
Flyback refers to the sudden reversal of voltage that occurs when the magnetic field around an inductive load collapses. In relay circuits, when the relay coil is de-energized, the collapsing magnetic field induces a voltage spike of opposite polarity across the coil terminals. This flyback voltage spike can reach levels that exceed the voltage ratings of other components in the circuit, potentially causing damage. A diode used in reverse bias across the relay coil provides a path for this flyback current to circulate and dissipate, thereby protecting the circuit from the harmful effects of the flyback voltage.
A diode is used in a relay circuit primarily to protect the circuit from voltage spikes generated by the relay coil when it is de-energized. When the relay coil is energized, it creates a magnetic field that closes the relay contacts. When the coil is de-energized, the collapse of this magnetic field induces a high voltage spike in the opposite polarity across the coil terminals. This spike can damage sensitive components like transistors or microcontrollers in the circuit. By placing a diode in reverse bias across the relay coil terminals, known as a flyback diode, the diode conducts when the voltage spike occurs, providing a path for the current to dissipate safely. Thus, the diode protects the rest of the circuit from the harmful effects of the voltage spike generated by the relay coil.