We found this circuit in the November 1975 issue of Radio Electronics magazine. It uses a digital module from the time with several adjustments. The power supply must have the indicated voltage.
This circuit is from 1983 documentation. The author shows us an experimental circuit of a siren...
This simple circuit indicates whether at a point in the wiring of a car 12 V is present. The clip...
This oscillator employs a Motorola operational amplifier common in the 70s. We can implement the...