Instructables

Can an ir transistor(fototransistor) detect a narrow range of frequency??

i am making wireless controlled led suits for dance show so i want to know if such transistors exist

iceng10 months ago
YES, you can use an 8 pin IC that strobes an IR LED and reads a synced photo detector.
IF the LED pulsing matches the gated photo sensor
Then it flags a line.

Obviously this ignores stage lights even if they are incandescent IR sources.
Further adding a FET gain stage the IR strobe can drive a power IR LED and
the Si1102 can drive a detection range in meters.
steveastrouk10 months ago
Do you mean optical frequency (colour, Thz) or transmission frequency (Khz?
Yes IR phototransistors and Pin diodes have a frequency they work best in if you look at the datasheets in them you will find “Relative Spectral Sensitivity” graph. That is what you are looking for.
steveastrouk10 months ago
Yes, easily. The harder problem is getting good modulation to the SOURCE of light, if the bandwidth is wide.

Steve