Suggested by a 90s Popular Electronics this circuit is intended to receive volleys or whistles from thunderstorms in the wave range below 20 kHz. The coil consists of 300 turns of wire 26 in a ferrite rod.
We found this circuit in an old neon lamp application manual. The circuit stores a call. The...
Poptronics recommends this circuit for use in the car when the headlights are left on. The circuit...
We found this circuit in a 1981 publication, when it was still possible to find 22.5 V batteries (used...