This frequency triple oscillator circuit was found in an American publication in 1967. The FET is current and more detailed information about the coils is not given.
This circuit was found in a 90s Hands On Electronics. It monitors the presence of voltage in a...
This circuit for TTL probes uses a 7400 as the main element. The circuit memorizes the signal...
This circuit was obtained from a 1985 Electronic Desing. The circuit uses a Darlington which may be...