A circuit board relay is a component that is mounted on a board and used to turn ON / OFF and switch the electric circuit based on the received electric signal. The circuit board relay consists of an electromagnet and a contact mechanism, and the contact mechanism operates using the electromagnetic attraction generated when current flows through the electromagnet. There are three types of circuit board relays, which are further divided into contact and non-contact types depending on the connection method. Signal relays have the function of transmitting ON and OFF, and power relays are relays mainly used for switching high-voltage and high-power loads of 3 A or more. Signal relays and power relays are contact relays that ensure insulation between the input and output sections. The SSR (for circuit boards) is switched ON and OFF by a semiconductor element without contact. The SSR (for circuit boards) is a non-contact relay and switches electronically. Features include low noise, impact resistance, high-speed response, etc.