Why car wheels are so flat these days

Re:Why car wheels are so flat these days by sbradford26 on Wednesday September 14, 2022 @08:56AM (#32836494)

So looking into it a bit there are what is called Eddy current brakes. In the section of disk eddy current brakes it talks about the power tool implementation where there is just a metal disk and the magnetics are pulled away from the disk when the device is powered on and passively return to the disk when power is removed. Something like that could work, but I am unsure of the size of magnets or disks necessary to adequately stop a vehicle. Most likely you could also add a normally closed relay hooking the motor to a resistor load. So when power is applied the resistor load is disconnected, and in a loss of power event the motor is directly tied to the resistor load.

https://en.wikipedia.org/wiki/Eddy_current_brake

[ Parent | on HN ]

Re:Why car wheels are so flat these days by hoosieree on Wednesday September 14, 2022 @12:38PM (#32839658)

Eddy currents develop in proportion to the speed of the moving magnetic field. So if you used eddy currents for braking, it would be most effective at high speed and gradually have no stopping power at low speed.

[ Parent | on HN ]

Re:Why car wheels are so flat these days by sbradford26 on Wednesday September 14, 2022 @02:57PM (#32841645)

That is mostly true about regenerative braking as well. Once you hit a certain speed the vehicle has to use some energy to get the motors to actually stop the vehicle. Usually EVs and such will just rely on the friction brakes for the last bit but some cars like the Bolt will automatically use some energy to slow the car to a stop so you can use do one pedal driving.

[ Parent | on HN ]

Re:Why car wheels are so flat these days by hoosieree on Friday September 16, 2022 @09:11PM (#32873906)

Good point, and a good reason to have friction brakes also installed.

[ Parent | on HN ]