Car windscreen wipers - Activity
A practical application of an AND gate controlling car windscreen wipers is shown.
- The circuit simulates car windscreen wipers
- One switch simulates the car ignition and the other the wiper switch
- The AND gate produces an output only when both of its inputs are high
- The motor simulates the wiper drive motor
- The switches are stable either on or off (high or low).
- Close both switches by left clicking each in turn with the mouse.
- Point out that the motor is rotating and this simulates the windscreen wipers.
- Open one switch and show that the motor stops.
- Repeat this for the other switch and then for both switches.
- Explain the motor only comes on when both switches - the ignition and the wiper switch - are high simultaneously.