This highly sensitive light sensor was found in a 1970 General Electric documentation. The circuit can use the 2N2646 for the UJT and the phototransistor can be of any type.
This simple experimental circuit using only transistor produces a tone given by C1 and C2. Tone is...
This circuit was found in Popular Electronics from 1993. The 1458 consists of a double 555. The...
This signal amplifier for ATV in the 427 to 439 MHz band was found in a magazine 73 for radio...