Electromagnetic Marble-Run Gate

Press the switch to complete the circuit. The electromagnet pulls the metal pin upward, compressing the return spring and opening the gate. The marble then rolls down the ramp.

Electromagnet status
OFF — circuit open

Interactive labelled diagram

Electromagnetic marble-run gate A battery and switch power a coil around an iron core. The electromagnet pulls a vertical metal pin upward and compresses a spring. The pin clears the sloping ramp, allowing the marble to roll down. When the circuit opens, the spring expands and pushes the pin down again. Pin pulled up Spring pushes pin down Marble rolls down ramp POWER SOURCE − + Press switch Electromagnet Copper coil around an iron core becomes magnetic when current flows Moving metal pin Moves up to open the gate Compressed return spring Mounted at the end of the magnet and compressed when the pin rises Marble Waits uphill behind the gate pin Sloping ramp Gravity makes the marble roll down What turns it ON? Pressing the switch closes the circuit. Current flows from the power source through the coil. OFF: release or reset the switch

The marble is held uphill by the lowered gate pin. Press the switch to begin.

Offline interactive model for classroom demonstration. Open index.html in any modern browser.

← Simulations