This circuit was found in a 90s Popular Electronics. It also serves for the analysis of microcontroller signals. The power comes from the circuit under test.
The purpose of this 1985 circuit is to make the sound test of type 106 SCRs (MCR106, TIC106,...
Using the CMOS 4001 we found this circuit in the October 1974 Radio Electronics magazine. The...
We found this circuit in a 1957 Raytheon transistor publication. The circuit can be assembled with...