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.
One of the problems with common multimeters, especially analog ones, is that their low resistance scales...
This circuit was found in old documentation, but the setting applies to any operational. Resistors...
Vz determines the trigger point for this protection circuit. The SCR doesn’t need to be mounted on a...