Found in a 1980s manufacturer documentation, this circuit can be used as an optical shield. The integrated circuit is from the era and modern equivalents can be tried out.
This circuit allows you to read temperatures with a common digital voltmeter. We found it in the...
This circuit for the 1.5 to 15 V scaled ranges was found in a 1982 documentation, but uses current...
The integrated circuit of this 1976 configuration is the 7400 and the type crystal in televisions of the...