Indicated by Texas Instruments, this 1968 circuit measures the duration of a light pulse captured by a phototransistor. Equivalent phototransistors and transistors may be used.
This circuit was found in an American documentation from the 80's. The components are from that...
The circuit shown is from the Texas Instruments optoelectronics manual. It is intended for audio...
This circuit drive an LED with constant current determined by the values of the resistors of 10...