How can i find that my stepper motor is not running?

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Thread Starter

raj

hi friend

i am working on stepper motor control. how can i find that my motor is not run or run at any time? how can i sense running conditon of motor?

thank you
 
P
Just try using an optical encoder or less sophisticated "zero Position" counter (every time the servo revolves through 360 degrees a counter counts up one).

Paul Pierce
 
R

Rokicki, Andrew

You can put a shunt resistor on each phase.
This will allow you to look at the current.
And can be measured as voltage across the resistor.
 
M
A current sensor can be installed with c/w a set of dry contacts which could be taken back to your input card.

~Mista Mark
 
Hello raj,

I agree with what paul has suggested. If the driven part is a ferrous material then you can just try putting procimity pickup to get signals while the motor shaft is in motion... and same can be further utiilised...

regards

Pravin
 
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Robert Scott

It is hard to tell when a stepper motor fails to move. If you monitor the current very precisely you will see a subtle difference between a running motor and a stalled motor, but that difference is small and would have to be customized for each motor and application. I doubt that you can make it work reliably in production. The most reliable way to know for sure is to use external position feedback, such as an optical encoder.
 
Don't waste your time trying to sense changes in current/motor back emf for stall detection. Companies like IDC and Compumotor have been playing around with this and it only works above 0.5 rps or 1 rps....and they had Engineers work on this for years to get to work reliably.

Like the others have mentioned, probably the easiest thing to do is put an incremental encoder to detect if the motor has stalled. You can also use it for position verification if you want.

-Cameron Anderson
 
If not for a electronic problem, a stepper moter will run and advance steps properly if the load and the motor are matched correct. So usually people do not add the feature in the drive even if the probability of load fluctuating is serious.

They change the motor to higher capacity.

regards
Sekar
 
S
I've had good experiences using the Computmotor Gemini GT Steppers for this. If the motor is jammed (locked rotor), and you ramp your command to greater than ~3 rps, the drive can be configured to alert you of a stall condition - even if the stall occurred at speeds lower than 3 rps.

Obviously detecting a static stall (displaced rotor) is a different story.
 
hi friend

just to get common terminal of all coils in stepper motor
then connect each coil one by one, then see the rotation torque check if field effect presentation on each turn of coils.
 
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