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Q: Can the polarity of an electric motor be switched during operation to create a braking effect?
thanks
How strong would the braking effect be? Comparable to disc brakes, or alot less?
Could you stop a car alot faster by switching the polarity and/or applying disc brakes?
Electric motors have alot of torque, maybe there could be a system if you slammed on the brakes it locks the tires with friction brakes and then spins the wheels in reverse to stop the car super fast.
I dont know, but I'm surprised I havent heard more about this possibility.
It would stop the car faster. By the same logic your using it would be equally hard to push a car backwards with the wheels spinning as it would with its wheels locked.If your tires are spinning backwards while you're moving forwards, that's not going to stop you faster. This is because the friction between the tires and the road is now kinetic instead of static. If you want to stop quickly, you don't want your wheels to skid. This is the whole point of ABS.
Would it work? I mean if it could work that would be a huge +1 for the electric car. Electronic braking, no more replacing brake pads or rotors. Along with no more oil changes, no emissions tests, no engine maintenance, no pumping gas. Imagine that banner at some future electric car dealership. I hope eestor comes through!TEG said:If you simply reversed the polarity and tried to run the motor in reverse you would have a "fight" on your hands with both the batteries and the motor (now generator) trying to push current into each other. Unless you have something to collect or dissipate that current somewhere you are likely to heat up and burn something out. You could fry your motor controller, motor, batteries, wires, etc.
... somebody should connect a heavy flywheel to an AC motor, switch polarity during operation and see what happens
OK, maybe polarity isnt the right word. If you switch the positive and negative terminals of an AC motor, it will reverse direction. EX: The roadster has 2 gears, the motor runs backwards for reverse. No reverse gear is needed.AC means alternating current. AC motors runs on AC current which is constantly switching its direction i.e. polarity. You must be switching the polarity for the motor to run at all. If you do not do it, motors doesn't turn. Your suggestion doesn't make any sense.
Go read TEG's post again.