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.
September 2016 - Mouser Electgronics already has in stock the new moisture digital sensor HDC1010...
This circuit was found in a Radio Electronics of August 1952. The transistors are germanium types...
We found this Nicad cell charging circuit in an English publication from the 1970s. The circuit can...