We find this circuit in American documentation from the 1980s. It consists of a frequency folder using a varicap. The capacitors and coils depend on the frequency of operation.
We found this transistorized circuit in a 1985 documentation. The circuit can operate with...
We found this circuit in a Motorola documentation from 1978. The circuit is based on the LM324...
We found this simple alarm circuit in a 1981 documentation. As we can see, it is a car alarm...