This circuit is one of many that the reader can find in this section for testing crystals. The circuit uses an indicator LED. Transistor Q1 determines the maximum crystal frequency that can be tested.
With a touch of the push button the lamp is switched on. A new touch and the lamp go out, in this...
The LMV321 is a low voltage operational amplifier from ON Semiconductor. The following diagram,...
We find this circuit in an old American documentation. It can provide a 25 dB compression in a...