We found this circuit in a Radio Electronics magazine from November 1976. The clock frequency is divided by 10 and the maximum value depends on the integrated circuits used.
This circuit using only transistors was obtained from Ferranti's 1969 documentation. It can be...
This sensitive circuit can be designed with FETs such as BF245 and MPF102. The sensor is a silicon...
Found in Popular Electronics from the 90s, this circuit generates two tones that are selected by a...