Silonex Hermetically Sealed Photocell LED Opto-coupler. Opto-isolator.
Yellow LED and a single CdS Photocell in a sealed package.
A great item for experimenters and automation proto-typers. Also has applications in audio switching and effects.
Resistance of photocell measured between 470 and 490 Ohms when powering the LED with a single 1.5V AA battery.
Off resistance measured greater than 6 MegOhms.
Physically similar to NSL-32 coupler.