5N10.90-EM wave production

5n1090 5n1090c 5n1090b

Description: An electrostatic generator creates EM waves that can be viewed on the oscilloscope


  • Wimshurst’s Machine
  • Discharge Y wand
  • Large helmholtz coil (“receiver”)
  • Oscilloscope
  • Wires to connect the oscilloscope to the receiver
  • (Optional) Video Camera

Setup Procedure:

  1. Connect the oscilloscope to the receiver.
  2. Set the oscilloscope settings to match those in the third picture.
  3. If the video camera is needed, connect it to the AV equipment and focus it on the scope.
  4. Set the wimshurt’s electrodes to about 3cm apart.
  5. Make sure all 4 brushes are touching the wheels!
  6. When the professor is done, discharge the wimshurst’s machine and both capacitors.
  7. Move the electrodes together so they are touching.
  8. Take off the belts on the wimshurst’s machine.

Demonstration Procedure:

  1. Turn on the oscilloscope if it’s off.
  2. Start turning the wimshursts machine. You have to accelerate very slowly or the gears will skip.
  3. When the wimshurst machine discharges, you see the wave pattern on the oscilloscope being picked up by the helmholtz coil.
  4. Explain that this is a very elementary radio.
  5. When finished, discharge the wimshurst’s machine using the discharge Y wand.

High Voltage
Use caution when using this machine. High voltages are produced.
Always discharge the capacitors after use by touching the metal “Y” wand to both electrodes and both capacitors.
When discharging, do not touch any part of the metal on the “Y” wand (common mistake). If you do, you risk getting a large shock.