Found in the September 1982 issue of Radio Electronics magazine, this circuit triggers a relay intermittently. Triggering is done by a reed switch, but other types of sensors can be used.
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...