This circuit was found in a 90's Electronic Design. The circuit can be adapted to use modern components. The power supply is made with 5 V which allows its use as a shield sensor.
This circuit determines the frequency of a signal by beating with a known signal. The circuit was...
With the values of the components indicated, this timer controls intervals from a few seconds to a...
The purpose of this circuit is to automatically turn a water pump on and off. Sensor 1 is the...