This circuit was published in the July 1993 issue of Electronics Now magazine. It uses a sensor from the time and triggers a buzzer with a Sonalert-type oscillator.
In the figure we have a simple signal tracer circuit to be coupled to the volume control of an AM...
This circuit was found in documentation from the 90s, using components from that time. The...
This circuit, obtained from old documentation, allows the recovery of sulfated batteries. The...