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 circuit was found in the February 1981 issue of Radio Electronics magazine. The circuit uses...
Found in American documentation from the 90's, this circuit oscillates up to 150 MHz. The...
This circuit can work with power voltages from 6 to 35 V, being suggested by the Motorola Linear...