Operating at a frequency of around 180 kHz, this transmitter was found in a Science & Electronics of 1970. The coil has 34 turns of 22 wire. The transistor can be the 2N2222.
This circuit, found in a 1991 documentation, doubles the frequency of a TTL signal. The maximum...
This 4-20 mA current interface was found on a 90's EDN. The components used are not common today and...
This different power control circuit with SCR was obtained from a 1967 magazine. The SCR can be...