Solid State Relays

Solid state relays employ electronic components (MOSFETs, Triacs, etc.) in place of mechanical parts to control the on/off state of a circuit. Unlike electromechanical relays which can have a service life in the millions of cycles, solid state relays have a virtually infinite lifespan and will not wear out over time.

Available switching types include:

• DC switching for low-voltage DC loads
• Zero-cross switching for resistive AC loads - zero-crossing solid state relays wait for the AC signal to cross zero before energizing, ideally suited for most commercial and industrial loads such as resistive heating elements, lamps and ballasts, and any other load with low initial impedance or capacitive characteristics. They are preferred in applications with some level of capacitance as they can minimize surge currents during the first conduction cycle.
• Random switching for inductive AC loads - random turn-on (asynchronous) solid state relays do not wait for the AC signal to cross zero before energizing and are commonly used with inductive loads (motors, contactor coils, transformers), where the phase shift between voltage and current would be an issue with zero-crossing relays.

Solid state relays are available in several form factors and ratings:

• Panel mount relays, hockey puck style
• DIN-rail mount relays
• Socket mount relays
• Hazardous location (HAZLOC) relays

For part listings and specifications, go to Shop Now