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 configuration is from a 1964 US documentation valid for any FET. The range of power voltages...
Only the right combination of the positions of the 6 rotary switches of 1 pole x 10 positions of...
Another of the many anti-bounce circuits that we have in this section of our website. This one...