Current noise coming from Step Motor
Current noise coming from Step Motor
(OP)
We are currently using the A3959 chip from allegro. But we hear a noise coming from the end cap of the motor. It's sounds like the current circulating through the windings. This noise causes vibration in our machine when it's in holding mode. Does anybody know how to get rid of this noise and where it's coming from. We lowered hold current this helped but we can't lower hold current in our application.
http://www.allegromicro.com/sf/3959/
http://www.allegromicro.com/sf/3959/





RE: Current noise coming from Step Motor
It is something that you can change by adjusting the PWM frequency. You probably have the oscillator running at 4 MHz and your carrier frequency is a small fraction of that - so it is usually in the audible range. It is also possible that mechanical resonance amplifies the sound level. Try to change the Rosc (pin 4 in the DIP version). You can take it down 50 percent or up more than 100 percent by varying the Rosc value from 20 kohm to 100 kohm.
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: Current noise coming from Step Motor
RE: Current noise coming from Step Motor
Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: Current noise coming from Step Motor
I was doing some development work on a 3900 pound cast iron EDM machine and that would certainly shake it at different stepper speeds. Haven't seen this when one is "stopped." When you say you are holding, is your position determined by an external encoder? This may be caused by a control loop problem as well as the chopper speed.
RE: Current noise coming from Step Motor
RE: Current noise coming from Step Motor
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Current noise coming from Step Motor