treadmill motor choke

[Chuck in E. TN]

I have asked this question before, but I can’t remember where or when, nor can I remember the answer.
I have acquired 4 treadmill dc motors from ˝ to 2 hp. All were from
“Freecycled” treadmills. Out of the group, I have only 3 working controllers. The larger motors had large chokes inline with the motors. What is the choke for?
I have a MicroMark 7x14 lathe and an HF X2 mill. Neither has such a choke for their motors.
I started collecting the motors and controllers for spares in case anything happened to my lathe or mill, and to power other equipment as needed.
If  I  adapt one of these motors for use, would I need to incorporate the choke?
Can I just swap out motors on the lathe and mill for one of these?

Chuck in E. TN

[Bluechip]

Chuck

There for R.F.I. ( Radio Frequency Interference ) supression usually. On a commutator motor anyway.
Typically around 100-300uH, amps to suit motor.

Maybe in conjunction with a capacitor, or capacitor delta network, across the brushes.

Some small lathes etc. achieve the same end by putting a couple of turns of the the mains lead through a ferrite toroid, or passing it through a clip-on core.

Dave BC

[andyf]

Chuck

There for R.F.I. ( Radio Frequency Interference ) supression usually. On a commutator motor anyway.
Typically around 100-300uH, amps to suit motor.

Maybe in conjunction with a capacitor, or capacitor delta network, across the brushes.

Some small lathes etc. achieve the same end by putting a couple of turns of the the mains lead through a ferrite toroid, or passing it through a clip-on core.

RFI/EMC suppression, certainly. But I wonder if a choke also serves to stop feedback from the motor making the controller a bit unstable.

Andy

[crabsign69]

dont mean to sound dumb but what is a choke on these and what does it look like.  if you please


EDIT :never mind i found it )  choke :...

(Choke coils are inductances that isolate AC frequency currents from certain areas of a radio circuit. Chokes depend upon the property of self-inductance for their operation. They can be used to block alternating current while passing direct current (contrast with capacitor).
Common-mode choke coils are useful in a wide range of prevention of electromagnetic interference (EMI) and radio frequency interference (RFI) from power supply lines and for prevention of malfunctioning of electronic equipment. They pass differential currents (equal but opposite), while blocking common-mode currents.[1 )