Stepper Driver Questions

[Chuck in E. TN]

I purchased a 1 axis stepper driver board on e-bay. I expected it to come with an application data sheet or info on how to hook it up, but it didn't.
Picture here: Digital RT controller Photos by chucketn | Photobucket

On the left is the input from the control circuit from top to bottom +5v, Pul, Dir and EN. I do not know what values PUL, DIR and EN should be.
On the right from top to bottom: A+, A-, B+, B-, +24V, GND.

This driver is to become part of my Digital RT controller project.

Anyone familiar with this Stepper Driver? It's based on the TB6560AHO chip.

Can anyone suggest a simple test setup to see if it works?

I have a TEC CBA45-01101 3v unipolar stepper I want to drive with it.

I also have 5VDC and 12VDC wall warts to provide power for testing. I do know from the E-Bay listing it can handle 12-24v for stepper supply.How can I provide simple Pul, Dir and EN signals to the input? Can I safely drive a 3v stepper with 12v?


Chuck

[Kludge]

Okay, let me embarrass myself by trying to handle this.

First off, the TBB6560 data sheet is available via Google ... buuuttt ... because I'm such a nice guy, I've attached it.  (I hope.) 

PUL is pulse - one per step, voltage no higher than the power to the chip, DIR is Direction, same voltage restrictions, and EN is Enable, again same voltage restrictions.  They should operate from TTL levels - ie, somewhere in the 2.5-3.5v range.  +5 and GND are pretty clear.  +24 can actually be anything equal to or above the chip power voltage (+5v) with the chip being able to support up to 40v.  Why the limited it to 24v is known only to the driver manufacturer.  Anyway, it's the operating power for the motor.  The A+, A-, B+ and B- go to the motor windings with the "+24" going to the winding center taps or the closest local equivalent.  I'm hoping the wiring I have for the motor is the same as yours.  If it is, the black & white leads go to the +24v connection, Red to A+, Yellow to A-, Brown to B+ and Blue to B-. 

The motor power may be an issue even feeding it with only 5v.  Knocking that down to the preferred 3v would require a regulator in the power feed to the motor (the +24 connector) and I'd need to think about the best way to create one.  The chips exist up to around 3 amps but I'm thinking about the pulse current which can be several times the holding current. 

The switches at the bottom ... I'd leave them as is until you have a handle on getting the chip working according to Hoyle.  Or someone. 

Anyway, have I created enough chaos for you or are there still places that still aren't quite there yet?  :-)

[Chuck in E. TN]

Thanks Kludge. I was looking fpr more specific info on the whole driver circuit, not just the chip it's built around. I haven't completed the controller/display part of the project yet and wanted info on inputs and outputs for the Cinese Driver board the 6560 is on. I did finally get a response from the e-bay seller that provided enough info to test the driver board with the stepper it will controll. I filed the chip notes with my growing pile of motes on the project. thanks again Kludge.
 
Chuck

[John Swift]

Hi Chuck

the test circuit from gecko drive com will provide the step & direction signals to test the board

do you have any more information about the 3V steppermotors?

if not just measure the coil resistance , divide 3V by the resistance to find the current you need to set switches SW1 ,SW2, SW3   

I have found limited info for a board that looks like your board
my diagram shows the connections to the Gecko test circuit
   

http://www.ebay.co.uk/itm/CNC-Router-Single-1-Axis-3-5A-TB6560-Stepper-Stepping-Motor-Driver-Board-/170946672067?pt=LH_DefaultDomain_0&hash=item27cd3735c3

http://www.geckodrive.com/support.html

http://www.geckodrive.com/gecko/images/cms_files/Step%20Motor%20Basics%20Guide.pdf

http://www.geckodrive.com/support/application-notes/miscellaneous/step-and-direction-tester.html

http://www.cnczone.com/forums/general_electronics_discussion/110986-how_i_fixed_my_chinese.html



     John

[Chuck in E. TN]

John,
I had found the Gecko test Circuit. I in fact, hooked up the stepper to the driver with a 5v and 12v wall warts and got movement by jumpering the 5v to the pulse input, reversed movement by alternatly jumping the direction input to 5v and ground. I am convinced it works/ will work with the controller.
Chuck

[picclock]

Hi Chuck

hats an interesting stepper combination you have there. The driver board is a bipolar driver. This means that its for driving two coils which are isolated from the motor body. Bipolar motors are usually specified by their maximum current, although sometimes a breakdown voltage may be specified. Bipolar means that the current can flow either way in the windings which enables a fast changing magnetic field polarity.

Unipolar motors have center tapped winding(s) with the tap going to the supply. The motor is stepped by sequentially pulling the coli ends low, allowing a current to flow through them which creates the magnetic field. The problem with unipolar stepper motors is that there is no fast way to accelerate the magnetic decay. Additionally, as they are voltage driven, the current is limited by the winding resistance, which causes them to run much hotter for the same power.

If you increase the voltage on a bipolar stepper the current from the supply goes down and the current in the winding remains constant (or nearly so). On a unipolar motor the current increases pretty much in line with ohms law.

Not sure this post is helping you much. From a personal point of view, having used both types of stepper motor, I'd swap it out for a bipolar one and use a 12-24v supply.  Page 29 clearly shows the two bipolar motor windings on the right of the page.

Hope this helps a bit.

Best Regards

picclock
 


   

[Chuck in E. TN]

picclock, The stepper I have is a uni. I have wired it up to the driver as bi-polar. Seems to work o.k.
Chuck

[picclock]

Hi Chuck

I'm glad to see you dodged that bullet. It never occurred to me that you could do that, and I've never seen that done before. Presumably you can measure the resistance of the coil, work out the current at its rated voltage and set the driver accordingly. Once the current is set the driving voltage becomes relatively unimportant, so 12 - 30 V will likely make no difference, as the average voltage across the windings will be set by the current.

Is this to be direct drive to the worm gear of the RT ? I will be interested to see how it performs as I have a few unipolar motors in my junk box, which I've always thought of as junk which may have a new lease of life using this technique.

That's an Excellent solution 





Best Regards

picclock