Protection Circuits in Regulators- The series regulator using transistors has no short circuit protection. If the load terminals are shorted accidentally then,
- Large amount of load current will flow.
- The pass transistor Q1 will get destroyed.
- The diodes used in unregulated power supply, supplying the input voltage Vin
to regulator circuit may get destroyed.
To avoid all such possibilities some sort of current limiting must be provided to the series regulator.
The various protection circuits used for the series voltage regulators are,
- Constant current limiting (Short circuit protection).
- Fold back current limiting.
- Overvoltage protection.
- Thermal shutdown.