Keyestudio eight-channel solid state relay is active at HIGH level, that is to say, the input control signal is the high level (3.3-5 V), the relay is on; while the input control signal is low level (0-2.5 V), the relay is off.
Solid State Relay is a new kind of contactless switching device, which is composed of all solid state electronic components.
Compared with the electromagnetic relay, it has higher reliability, with the features of non-contact, long service life, fast speed and less outside interference.