Best Dc Motor Controller

OK. Here is what I have concluded from my research so far. Please correct me if I am wrong:

The main cause of noise/vibration I am experiencing is my selection of a SCR controller which is sending large amplitude pulses at 60Hz.
A PWC controller operating at 16KHz (stndard) would be much quieter .
A servo drive would work, but would require a more complex control system. This requires further research. It may be the ultimate solution.
I need a 4 quadrant controller to get the functionality I need.

I do not see that Dayton makes a controller that has 4 quadrant regen braking. Minarik makes one but it requires a large external resistor for brake energy dumping (not a deal breaker.) Also it is larger than my box (again not a deal breaker.) KB does not make one!? That chick in the Minarik video is kind of cute (except the voice.)

http://www.ebay.com/itm/MINARIK-NRG...869987?hash=item5d57cad863:g:EJkAAOSwNSxVMoWT

Robert
 
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Why do you need such a fancy controller? The Dayton one I use for my SBL does fine, speeding up or even slowing down. It handles dynamic braking ok. No instant stops, but quickly stops when you need it to do so. It has a forward reverse switch, but I use the old drum switch for reversing when needed. Ken
 
Ken- Please elaborate. What model controller are you using or at least what are it properties? PWC or SCR? Does it use a braking resistor? I admit reversing would be uncommon on my machine so perhaps I could just add a manual switch. I am concerned that all of the SCR controllers will be just as loud.

R
 
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I like the KB units. I found a new old stock KBIC-125 on Ebay for around 15 bucks, blew the dust out of it, wound up a .035 ohm "horsepower" resistor for it and it works fine. DPDT switch motor leads for reverse (with power off) Yes they do make the motor hum a bit, but I think they are more reliable than the mosfet "treadmill" types. Certainly easier to troubleshoot and repair- simple op-amp feedback, no digital jazz, tried and true. Daytons are similar.
My 2 cents.
Mark S.
 
Thanks for the replies. Mark- just so I am clear on the function. Does your KBIC brake the motor or does it just coast to a stop? If you reverse it with the motor running will it blow the controller?

Also- I just got this very informative email and I thought I would share it:

Hello Robert,

In regards to SCR 4Q drives, they are definitely audibly noisier than PWM drives. SCR drives switch voltage to the motor at 120Hz, so they produce a hum at lower speeds. PWM drives switch at over 16kHz and send filtered voltage to a motor. This makes the motor run very quiet.

SCR 4Q drive can provide braking without a DB resistor because the motor energy is fed back to the AC line. On PWM drives, the excess energy is fed back into the drives BUS capacitor. If the BUS capacitor becomes over charged, that’s when the DB circuit activates and bleeds off the excess voltage on the BUS cap.

I hope this helps.
Richard Lopez
Applications Engineer

Robert
 
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Hi Robert- No braking on my setup, and I don't reverse it under power- I probably should have a latching switch for the reversing function but I'm just careful, and the circuits are fuse-protected. I believe the controller has a "free-wheeling" diode which gives some braking after power down, I'll have to double check that.
Mark S.
 
I don't know about y'all but I am tired of trying to use a caliper while the chuck is still spinning! Stupid, yes but I know my limitations (patience). The dynamic brake is a real safety and convenience factor for me. Also, with the 8" 4 jaw the lathe takes about 30 minutes to coast to a stop.
R
 
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