This circuit uses a transistor to trigger the alarm from a low quiescent current sensor. The relay is 12 V. The circuit is from Radio Electronics magazine, April 1975.
We found this ladder-shaped signal generator circuit in Radio Electronics magazine from August 1966....
This powerful regulator, shown in the figure is for 5V (TTL) is suggested by Motorola and makes use...
The L3 coil is what basically determines the resonant frequency, around 1 MHz, in this oscillator found...