This circuit, found in a 1958 magazine, is for reference only, since the components are not easy to find today. The transistors are germanium types and power supply is made by common cells.
We found this logic level tester in a 1976 documentation. The circuit is powered by the voltage of the...
This sophisticated power supply for the laboratory of the maker or professional repaired was found...
Common diodes when forward biased present a voltage fall of about 0.6 to 0.7 V. This voltage fall...