The audio track is encoded as a translucent strip ... with a light source to decode the optical signal. She tried to use a photoresistor and a discrete photodiode, but neither had the required ...

[Fjord Carver] brings together an RGB LED and CdS Photoresistor to make a color sensor. Those Cadmium Sulfide lights sensors usually have a very wide swing of resistance when exposed to varying ...

Keypad & Audio Vandal Resistant: Yes No of Call Buttons on Panel: 1 call buttons Hands-free video intercom communication Supports two door stations in the intercom system Self-adaptive IR supplement ...