Audio Optocoupler / Opto-Isolator - LED/LDR package, "vactrols", Circuit Bending


-Tiny audio optocoupler is about the size of a pencil eraser and has 4 leads.
-These are used extensively in audio compressors, audio level controls, audio limiters, expanders/noise gates, guitar tremolo effects, guitar amplifiers and music effect boxes.
-Inside the black epoxy case is a 2 lead photocell (not a photodiode or photo-transistor) and a 2 lead LED.
-This is why the device finds extensive use in audio applications (photocell instead of photodiode).
-The LED requires about 10-16mA current and the resistance of the photocell varies from 150K up to megohms when the LED is off to under 400ohms when the LED is on.
-Brand New.
-Sold as Package of 2pcs

 *NOTE: Dot on case marks the cathode (-) lead of the LED.