ESC, adding an inductor, useful or not?

[spinningmagnets]

I recently bought a Miking 120A ESC, which is working well so far. It has what appears to be an iron doughnut-inductor (Toroid?) on the servo-wire. Since these components were designed to be used with model aircraft and helicopters, are they a waste of time for E-bike uses, or should I keep it on?



I have a low-amp 22V RC-Friction-Drive, using an Exceed 295-kV, and a Turnigy 280-kV. Rather than string several short pigtails together to reach from the rear wheel drive to the handlebar throttle, I intend to make a single long 3-wire servo-cable with no extra connectors in the middle. Heres the Wiki on "Inductors":

http://en.wikipedia.org/wiki/Inductor

If they are in fact useful to us, where should they be located in a long run? by what criteria do we select a new inductor to add? (they are very cheap) If I add a big enough doughnut-inductor so that I can fit a tiny servo connector through the center hole, will the larger size make the inductor performance better or worse?

Inductors come in many shapes, would the beer-can "choke" inductor (often found on laptop charger cords) or the Pizza-inductor work better for this application? I'll check back later, right now this thread is making me hungry...

http://endless-sphere.com/forums/viewtopic.php?f=14&t=10986&start=60#p239597
http://endless-sphere.com/forums/viewtopic.php?f=2&t=23205&p=342285#p342285

 

[Thud]

Spin,
The ferite torid on the servo wire acts as a choke to eliminate any (or most of the) back noise coming from the motor getting into the radio receiver.

A very good question though regarding inductors....like: what would the math look like to calculate a minimum inductor for a hyper wound motor to be handled by a simple controller...

I will let the experts chime in on the +/- of added inductors for our applications.

 

[texaspyro]

Frankly, a ferrite on signal lines is not going to do anything useful/noticeable in the real world. They appear when a device is just over some RF emissions limit during FCC interference testing and needs to have a couple dB of RF noise knocked off so that it can be certified.

 

[spinningmagnets]

Would a heavy PWM mode create a lot of RF, if yes, would that RF scramble some of the 0V-5V throttle signal? would RF contribute to sync loss by hurting the ESC-chips ability to sense the back-EMF? would inductors help any of that?