1 Answer
A basic flyback diode is used to protect circuits from **inductive kickback**, which is a high-voltage spike caused when the current through an inductor is suddenly interrupted. Inductors (like relays, motors, or solenoids) store energy in their magnetic fields when current flows through them. If the current is suddenly turned off, the collapsing magnetic field generates a high voltage in the opposite direction to keep the current flowing, which can potentially damage other components in the circuit.
### Here's how the flyback diode works:
- **When the switch is closed and current is flowing through the inductor**: The inductor is storing energy in its magnetic field.
- **When the switch is opened suddenly**: The inductor tries to maintain the current flow, causing the voltage to spike (this is the inductive kickback).
- **The flyback diode comes into play**: The diode is placed **in parallel** with the inductor but oriented in such a way that it doesn't conduct while the switch is closed and current is flowing normally.
- **When the switch opens and the inductive kickback occurs**: The voltage across the inductor tries to rise to dangerous levels, but the flyback diode provides a path for the current to circulate through the inductor and the diode, instead of creating a high voltage spike. The diode "clamps" the voltage to a safe level, typically to the forward voltage of the diode, preventing damage to other components in the circuit.
So, the flyback diode essentially **redirects** the energy stored in the inductor safely back through the inductor, preventing the high-voltage spike that could damage sensitive components like transistors or microcontrollers.
### Here's how the flyback diode works:
- **When the switch is closed and current is flowing through the inductor**: The inductor is storing energy in its magnetic field.
- **When the switch is opened suddenly**: The inductor tries to maintain the current flow, causing the voltage to spike (this is the inductive kickback).
- **The flyback diode comes into play**: The diode is placed **in parallel** with the inductor but oriented in such a way that it doesn't conduct while the switch is closed and current is flowing normally.
- **When the switch opens and the inductive kickback occurs**: The voltage across the inductor tries to rise to dangerous levels, but the flyback diode provides a path for the current to circulate through the inductor and the diode, instead of creating a high voltage spike. The diode "clamps" the voltage to a safe level, typically to the forward voltage of the diode, preventing damage to other components in the circuit.
So, the flyback diode essentially **redirects** the energy stored in the inductor safely back through the inductor, preventing the high-voltage spike that could damage sensitive components like transistors or microcontrollers.