In the field of medical equipment, the equipment has strict requirements of frequent and precise operations, so the components of medical equipment should have nice performance (high precision, durability, etc.). Solid state relays can meet these demands of most medical devices. For example, the infrared radiation devices have a huge thermal inertia, but by connecting the solid-state relay to the radiation plate, it becomes very easy to control the temperature of the infrared radiation device through the SSR relay.