Using an analog microamperimeter this circuit has a phototransistor adapted to the wheel as a sensor. The circuit is from American documentation from the 1980s, but the components are common today.
This circuit measures alternating voltages on 5 scales and its accuracy depends on the tolerance of the...
This circuit was obtained in an American documentation translated in the 80's. The circuit can be...
Figure bellow shows another configuratíon for a Iow-frequency sine wave oscillator using CMOS...