Braking
How eddy-current braking works
Magnetic drag slows a moving conductor without contact. This guide explains the principle, field-source options and limits.
Motion becomes heat
A conductor moving through a magnetic field develops circulating currents. Their magnetic field opposes the motion, producing a braking force across an air gap. The absorbed energy becomes heat.
Force depends on speed and the magnetic and conducting geometry. It falls to zero at standstill and need not keep increasing at high speed.
Slowing is not holding. An eddy-current brake cannot hold a stationary load. The system must provide separate low-speed stopping and holding arrangements where required.
Permanent magnets or powered coils?
| Design choice | Permanent magnets | Powered coils |
|---|---|---|
| Supply | No electrical supply needed for the magnetic field. | Electrical supply and control required. |
| Control | Field remains present while the magnet and conductor are engaged. | Excitation can be controlled or switched. |
| Typical fit | Passive braking, including duties where loss of supply must not remove the field. | Applications requiring commanded excitation. |
Axis supplies the permanent-magnet option. A passive field is useful during power loss; the complete braking and holding system still needs its own safety assessment.
Where it fits
- Transit: supplementary dynamic braking for repeated service stops.
- Launch and test systems: high-energy deceleration of rides and sleds.
- Industrial handling: controlled slowing of carriages and conveyors.
What sets the rating?
There are no friction pads to wear, but the energy still has to be dissipated. Plate and magnet temperatures, cooling between stops, gap and alignment determine usable performance.
Specify the load mass, speed range, braking distance, repetition rate and holding duty. Model the complete cycle rather than assuming that contactless means maintenance-free or unaffected by heat.
Discuss a braking duty
Send the load, speed range and repetition rate.