This circuit can be used to test crystals from 1 to 20 MHz and also has an output to measure their frequency. We found it in the November 1998 Electronics Now magazine.
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...