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.
Found in an American documentation, this circuit shows how an interface should be made for...
We found this circuit in an old American documentation from the 70s. The Triac can be of any type...
The operating principle of this circuit, from a 1956 publication, is simple to understand. The...