Found in the October 1979 Radio Electronics magazine, the purpose of this circuit is to monitor the coolant level in a car's radiator. The circuit is based on the LM1830.
In the figure we have the use of one of the four existing amplifiers in the LM2900 and LM3900 as a...
We found this circuit in a 1975 publication. The power supply must be symmetrical, but other...
This circuit was found in old documentation. PUTs are uncommon components today. The circuit...