Advantages of Solid state relays
Most of the relative advantages of solid state and electromechanical relays are common to all solid-state as against electromechanical devices.
• Slimmer profile, allowing tighter packing.
• Totally silent operation.
• SSRs switch faster than electromechanical relays; the switching time of a typical optically coupled SSR is dependent on the time needed to power the LED on and off – of the order of microseconds to milliseconds.
• Increased lifetime, even if it is activated many times, as there are no moving parts to wear and no contacts to pit or build up carbon.
• Output resistance remains constant regardless of amount of use.
• Clean, bounceless operation.
• No sparking, allows it to be used in explosive environments, where it is critical that no spark is generated during switching.
• Inherently smaller than a mechanical relay of similar specification (if desired may have the same “casing” form factor for interchangeability).
• Much less sensitive to storage and operating environment factors such as mechanical shock, vibration, humidity, and external magnetic fields.