Specifications: The APY277G1E is a through-hole DIP-4 PhotoMOS SSR, a 1 Form A (SPST-NO) device rated for 700mA at 200V AC/DC. It features a low 0.5Ω on-state resistance, 5000Vrms isolation, and switching times of 800μs (turn-on) and 50μs (turn-off). It operates from -40°C to 85℃ with a 1.2-1.5VDC control input. Application Scenarios: A compact through-hole relay for medium-current, higher-voltage switching. Common applications include industrial control of 3-phase monitoring relays, HVAC compressor and fan controls, appliance motor control, power management in renewable energy systems, and as a reliable interface in professional audio/video equipment, offering a balance of performance and ease of manual assembly or prototyping.