This commercial 6-digit clock circuit was found in August 1976 Radio Electronics magazine. Note the supply voltages and the use of a period module.
This circuit converts BCD inputs to analog voltages. The operational amplifier must be powered...
This circuit is suitable for the calibration of old analog oscilloscopes. It was found in...
This is the circuit of a hearing aid amplifier manufactured by Sony in the 1960s. The circuit was...