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 small receiver uses CK722 transistors and was found in a documentation by Hugo Gernsback from...
Using this circuit the lamps glow in sequence in a speed given by the capacitors. The SCRs present a...
This circuit generates short pulses. The transistor can be a 2N2222 or BC548 and the frequency is given by...