This 40-second delay switch was found in a 1965 Electronic Design. The unijunction transistor might be the 2N2646 and the SCR a sensitive modern equivalent.
This circuit was found in an American documentation from 1970. We can increase the number of...
This amplifier with the RCA CA3018 integrated circuit was found in the August 1970 issue of Radio...
This three-transistor circuit can control 3 V relays or servos from 17 MHz modulated transmitters. The...