Inrush Current Limiter Circuit. Such inrush current could come from motor start up dc. Inrush current limiter circuits icl with triacs and thyristors scr and controlled bridge design tips introduction at application start up a high current can be sunk from the mains due to transient energy demand to start the system.
This type of ntc inrush current limiter circuit can be commonly found in power supply units like ac dc converters or smps circuits. An inrush current limiter circuit limits the input current and keeps the source and the host device safer. To avoid possible component damage caused by inrush current an inrush limiting circuit is generally required for an ac dc power supply.
Inrush current is harmful because of the following reasons high inrush current affects the source power supply.
Inrush current limiters are typically installed in either locations a b or c d and depending on applications sometimes only on location a or c. To limit inrush current an ntc thermistor is placed between the power supply and system see figure 1. Advantages of ntc thermistors ntc thermistors are temperature dependent resistors that employ special semiconductor ceramics with a negative temperature coefficient ntc. The value of the inrush current is much higher than the steady state current of the circuit and this high current can damage the device or trigger the circuit breaker.
