DescriptionHigh voltage level trigger refers to a forward voltage between signal trigger end(IN) and power cathode, is a trigger way of connecting anode of power with trigger end. When there is forward voltage or the voltage reaches to a certain trigger amount at the trigger end, relay is actuated. Low voltage level trigger refers to the voltage between signal trigger end and power cathode is 0 V, or voltage of trigger end is lower than that of power anode, and relay is actuated. Usually connect power cathode with trigger end.