The MODDA four-channel solid-state relay (SSR) module can be used to quickly and efficiently switch AC loads on and off without the need for moving parts, as found in a traditional electromechanical relay. The SSR module utilizes a phototriac to provide galvanic isolation between the logic level and the AC load side. All four channels can be activated with a high logic level signal (3 - 5 V) by providing a low logic level signal (0 - 1.5 V) at its corresponding channel signal input. Please note that this module can only switch AC currents up to a maximum of 2 A with a maximum voltage of 240 V AC. Attempting to use this module to switch DC loads or exceed the specified limits may damage the module and/or your connected devices.