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 useful power supply can provide voltages from 0 to 12 V with currents up to 2 A, set in...
This circuit of old documentation can be implemented with modern operational amplifiers. The...
The base of this circuit is 1/4 of an integrated circuit 4136 which consists of a quadruple 741....