Found in a documentation from the 90's, this circuit uses only one integrated circuit. The resistors in series with the LEDs depend on the power that can be between 5 and 12 V.
The purpose of this circuit is to sense the water level in the windshield wiper reservoir. The circuit...
We found this circuit in Popular Electronics from January/February 1969. The circuit must be...
This circuit shows how to interface a CMOS circuit with a microcontroller or other circuit using an...