The ports used in this ultrasonic remote-control transmitter are TTL, requiring a 5 V supply. The transducer is a piezoelectric type, not very common today.
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...