This circuit uses a common multimeter on the voltage scale. The calibration of the scale should be done based on transistors with known gains.
For analog lines, this circuit was found in the August 1994 issue of Electronics Now magazine. The...
This circuit has a traditional configuration often found on this site. The transistor must be...
This 4-digit counter, using CMOS technology, was found in a 1997 documentation. The circuit is...