This transistor tester with different gain ranges was found in documentation from the 1980s. The circuit can still be implemented with more modern components and used with general purpose transistors.
This is a voltmeter with high input resistance. The transistor is germanium. We found it in an...
In this circuit, the relay remains closed by activating a lamp, for a time that depends on the...
The frequency depends on C, which must have the indicated value ratio, and also on R, which can be...