This circuit with germanium transistors is from 1960 and was found in Mullard's transistor application manual from 1960. The circuit can be adapted to use more modern transistors.
This circuit with unijunction transistors was found in a documentation from the 80's. The trigger...
We found this alarm in an English publication from 1978. Although the original power supply is 3...
This TTL circuit was found in the February 1973 issue of Radio Electronics magazine. The power...