Dynamo

A red mechanical dynamo device enclosed in clear pespex sits on a black bench, that is surrounded on two sides by brown and white information panels.
A red mechanical dynamo device enclosed in clear pespex sits on a black bench, that is surrounded on two sides by brown and white information panels.

Combining magnets, copper and iron bars creates an electric field.

How it works

Spin a magnet past an iron bar wrapped in copper wire to generate an electric field and illuminate lights on a meter.

Things to try or ask around the exhibit

  • How many lights glow on the meter?
  • What difference do you notice when the magnet is spinning and the magnet is stationary?
  • If you substituted a plastic bar for the iron bar, would you get the same result?
  • How is your home's electricity generated in a power station?

Background

Together, the magnet, iron bar and copper wire coils make an electric dynamo. The strong magnet spins past an iron bar wrapped in copper wire coils. The magnet causes a pulse of electric field as it moves past the copper coils.

The faster you spin, the stronger the electric field becomes and more lights are illuminated.

Finding the science in your world

While dynamos have been studied since the 1800s, they now tend to be restricted to low voltage battery 'wind up' gadgets such as hand powered flashlights.

Most power stations that generate electricity for a town or city burn fossil fuels to release energy that is then used to spin giant dynamo-like generators as well as turbines.