The CR9421 Series is a low cost, self powered, fixed set-point Current Switch designed for applications that require an on-off indication of current flow. The normal state of the switch is On when the current level is zero. Current levels above the guaranteed full-off level will turn the output to Off. The Current Switch is recommended only for applications where the continuous operating level is above the rated full on level of 350 mA. Operation below this point will not drive the output device full-on and derate the output ratings. The unit available with ACA output for AC switching. Connections can be made directly to items such as a PLC or electro-mechanical relay. Note that connections made directly to an inductive device such as an electro-mechanical relay will require a customer supplied clamping diode for DC operation or a snubber network for AC operation.