This approach alarm circuit was found in the September 1970 Radio Electronics issue. The 1 mH coil is wound on a ferrite rod. The relay is 12 V sensitive.
This microphone preamp found in a 1995 documentation offers stable microphone operation. The...
This high input impedance amplifier stage was found in a 1963 documentation. The transistor...
We found this oscillator in an English documentation from 1977. The symmetrical supply, in fact,...