Specifications: The APV412E is the through-hole DIP-6 version of a Normally Closed (1 Form B, SPST-NC) PhotoMOS SSR. It is rated for 500mA at 60V AC/DC. It has a 1Ω on-state resistance, provides 5000Vrms isolation, and features switching times of 200μs (turn-on, opens) and 500μs (turn-off, closes). It operates from -40°C to 85℃ with a 1.2-1.4VDC input. Application Scenarios: Designed for fail-safe applications where through-hole mounting is preferred. Common uses include safety interlock circuits, emergency stop (E-stop) systems, alarm system triggers, and watchdog timer circuits in industrial control panels, prototype safety systems, and any application requiring a guaranteed default conductive path that can be actively opened by the control circuit.