Eddy current brake with Cobra DigiCart

Principle

If a change in the magnetic flux is caused in a conductor, a voltage is induced in the conductor according to Farady's law, which leads to so-called eddy currents. These eddy currents in turn generate their own magnetic field, which, according to Lenz's law, counteracts its cause. If the change in flux in a metal is triggered by the passing of a magnet, magnetic fields are created in the metal which inhibit the movement of the magnet and cause it to slow down.

Benefits

• Free measuring software DigiCartAPP for all mobile devices and all operating systems (Windows, Android, iOS).
• Especially understandable and didactically prepared test description can be called up in the DigiCartAPP.
• Complete evaluation function for the measured data directly in the DigiCartAPP.
• DigiCart:
  • Long-life lithium-ion batteries with charge protection function
  • Transmission of measurement data via Bluetooth 4.0
  • Integrated sensors (force, speed, acceleration and position sensor)
• Digital measured value acquisition:
  • Future-oriented teaching: Integration into digital science lessons with tablets or smartphones.
  • Increased student motivation by using the intuitive DigiCartAPP.
  • Increase of media competence.

Tasks

Let the DigiCart with a mounted magnet move along an aluminium plate which is mounted on the side of the track. Study the braking behaviour within the different zones of the aluminium sheet.

Learning Objectives

In this experiment the students learn something about the eddy current brake. It enables wear-free braking and represents an application of Lenz's rule.