Eaton’s Solid-State Relay offering consists of 42 catalog numbers in three different form-factors: the traditional “hockey puck” style, compact DIN rail mounted style, and a DIN rail or “panel mount” style with an integrated heat sink. These relays provide a full range of solutions for applications requiring high switching cycles and/or low noise. All of the products carry full UL and CSA certifications and are RoHS compliant.
A solid-state relay (SSR) can perform many tasks that an electromechanical relay (EMR) can perform. The SSR differs in that it has no moving mechanical parts within it. It is essentially an electronic device that relies on the electrical, magnetic, and optical properties of semiconductors and electrical components to achieve its isolation and relay switching function.
Solid-state relays are similar to electromechanical relays, in that both use a control circuit and a separate circuit for switching the load. When voltage is applied to the input of the SSR, the relay is energized by a light-emitting diode. The light from the diode is beamed into a light-sensitive semiconductor that, in the case of zero-voltage crossover relays, conditions the control circuit to turn on the output solid-state switch at the next zero-voltage crossover. In the case of non zero voltage crossover relays, the output solid-state switch is turned on at the precise voltage occurring at the time. Removal of the input power disables the control circuit and the solid-state switch is turned off when the load current passes through the zero point of its cycle.