The circuit shown was found in Intersil documentation from the 90s. The formula allows to calculate the voltage obtained as a function of the values of the resistors.
This circuit uses reed switches as sensors. We found it in a 1992 documentation. A float at a...
One of the problems with analog multimeters is the non-linearity of the resistance scale. This...
I found this circuit in an old English magazine from 1979, but it can be easily assembled with...