BUY P627-1 https://www.utsource.net/itm/p/1712550.html

The P627-1 is a 4-pin DIP (dual in-line package) optocoupler manufactured by Vishay Intertechnology. It is an optically coupled isolator consisting of an infrared light-emitting diode and a silicon phototransistor. The device is designed to provide electrical isolation between two circuits while transferring a signal from one to the other. The P627-1 has a maximum isolation voltage of 5000 Vrms and a minimum CTR (current transfer ratio) of 50%. It is designed for use in low-voltage applications and is suitable for use in logic-level and power-level isolation applications. It is also suitable for use in applications such as motor control, power supplies, and industrial automation. (For reference only)