Author Topic: pwm into another pwm motor controller?  (Read 801 times)

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Offline mstachoTopic starter

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pwm into another pwm motor controller?
« on: June 14, 2011, 09:09:54 AM »
We have a black box motor controller that takes a 0-5V analog signal and turns it into (I think) a PWM input to a 48V, 60A motor.  Suffice it to say the motor needs enough power to make it impractical for me to just make my own controller.

We have another system that generates a PWM motor control signal.  So here's the question:  can I just hook the PWM output of this system into the analog input of the black box?  Will that work just like if we had supplied the actual analog voltage?

If not, is there a particularly easy way to turn PWM into an analog voltage?

MIKE
Current project: tactile sensing systems for multifingered robot hands

Offline newInRobotics

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Re: pwm into another pwm motor controller?
« Reply #1 on: June 14, 2011, 10:43:59 AM »
Hi there.

can I just hook the PWM output of this system into the analog input of the black box?  Will that work just like if we had supplied the actual analog voltage?
No it would not work, it would still be PWM instead of analog voltage.

If not, is there a particularly easy way to turn PWM into an analog voltage?
Yes there is. You need to use resistor in series with PWM output followed by a capacitor (Low Pass filter). Use Sabertooth 2x25 User’s Guide, page 11, as a reference.
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Offline mstachoTopic starter

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Re: pwm into another pwm motor controller?
« Reply #2 on: June 14, 2011, 02:41:50 PM »
Um...this might get posted twice, sorry if it does:

Awesome, that's just what I needed.  thanks.

MIKE
Current project: tactile sensing systems for multifingered robot hands

Offline newInRobotics

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Re: pwm into another pwm motor controller?
« Reply #3 on: June 15, 2011, 09:30:49 AM »
No problem at all  :)
"Computer games don't affect kids; I mean if Pac-Man affected us as kids, we'd all be running around in darkened rooms, munching magic pills and listening to repetitive electronic music." - Kristian W

 


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