How to protect a linear power supply from overcurrent?

The occurrence of overcurrent, overload, and short circuit conditions can damage the linear power supplies and affect the total useful life of the power source. Several current limiting techniques are commonly employed to protect the linear power supplies from such faults. Foldback current limiting method is one such overcurrent protection scheme.

Does a power supply have a current limiting circuit?

Most power supplies already have current limiting circuits in them as it is. However it may be supply as the sensitive circuitry. Computers are a good example of the application of current limiting circuitry. In a computer, multiple voltages and amperages are needed.

What happens if a power supply is overloaded?

When the power supply is overloaded, the output current increases and can go beyond the maximum current rating of the supply. When the power supply comes with the constant current limiting feature, the power supply moves from constant voltage to constant current mode under overloads.

Why should a voltage limit be exceeded?

In addition, the voltage should exceed certain limits to prevent electrical shocks for the end user. Limiting power, current and voltage also has a multitude of associated benefits, which include reduced wire gauges for output interconnections, reduced component stress for downstream converters, reduced system cost and increased system reliability.

How does a constant current limiting protection scheme work?

In the constant current limiting protection scheme, the supply will move back to constant voltage mode once the overload is removed. Under short-circuiting conditions, the current drawn from the power supply is not linearly reduced in the constant current limiting method, and this leads to large power dissipation.

What is constant current limiting mode?

Under constant current limiting mode, the power supply never gets tripped down to zero. The foldback current limiting method trips down the power supply and the voltage output will be equal to zero under this condition. The major share of our voltage requirements are fulfilled by Switch-Mode Power Supplies (SMPS).