This circuit is from an American manual from 1975. The transistors are types of the time, but equivalents can be used, as well as the relay that can be according to the supply voltage.
This circuit was found in a 1968 RCA documentation. The circuit can be designed with operational...
This resistance meter with the CA3130 was found in an English publication from 1977. The circuit has...
This is the 1968 MR480 commercial cassette recorder circuit. The circuit was fully transistorized and...