This circuit for the 60 kHz range was found in 73 magazine and published in 1995. The circuit uses a ferrite rod. Note the direction of the coil windings.
This conventional slow-moving circuit uses incandescent light bulbs, but can be changed to use...
This TTL dice is from an old publication from 1978, but it can still be assembled, as the...
The purpose of this circuit is to control magnetic door locks activated by the power grid. The...