Solid State Relay 24-380V SSR-90DA

Switches AC loads electronically rather than with mechanical contacts, which changes what it is capable of. There is nothing to wear out, no arcing, no clicking, and it can switch thousands of times per hour where a mechanical relay would fail within months — which is exactly what PID temperature control needs. Controlled by a 3-32V DC signal, so an Arduino pin drives it directly. Two things that catch people out: it needs a heatsink at anything approaching its rating, and solid state relays leak a small current even when off, so they must not be relied upon as an isolation or safety disconnect. No moving parts, nothing to wear out or arc; Switches rapidly and silently for PID temperature control; Driven directly from a 3-32V DC logic signal; Zero-crossing switching reduces electrical noise