This is a circuit for receiving signals from the previous transmitter. The circuit uses a common phototransistor. It was found in the August 1984 issue of Radio Electronics magazine.
This SCR relaxation oscillator was found in an 80's Electronic Design. It flashes a small...
We found this shield circuit in a 1991 technical documentation. The phototransistor can be...
This circuit for old photo enlargers was found in a 1970s RCA manual. The components are from the...