This amplifier was found in a 1970s documentation. Darlington transistors can be replaced for modern equivalents of at least 80 V x 2 A, equipped with good heat sinks.
This classic windscreen wiper interval setup was found in American documentation from the 90s. The...
This circuit, found in an American publication from the 1970s, produces an audible tone in a...
The circuit presented is a documentation for radio amateurs from 1978. Implemented with common CMOS...