Go Down

Topic: Selecting the right darlington arrangment for Stepper Motor (Read 2772 times) previous topic - next topic

IsaiasCtz

Hello everyone, Im having some trouble on selecting the correct driver to control my Stepper motor.
My stepper motor is a Model 57BYGH420 and it consumes 2A.
Right now im using a L293B but with no succes, the Stepper wont move, Im guessing that it is because it
dosent provide enough current to move it.
 :smiley-sad-blue:

Robin2

Post a link to the datasheet for your motor.

Have a look at stepper motor basics. It may answer your questions.

...R
Two or three hours spent thinking and reading documentation solves most programming problems.

IsaiasCtz

Post a link to the datasheet for your motor.

Have a look at stepper motor basics. It may answer your questions.

...R
Here is the datasheet:
http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Robotics/57BYGH420.PDF

and about your link I already read it.

Chagrin

If you're using L293's then you're wiring your motor in bipolar mode. If you want to use discrete transistors then you're either trying to wire it in unipolar mode or you're trying to build two H bridges to keep it in bipolar mode. You'll need to explain.

With the L293 wiring it should move even if you're not able to supply it with the 2A it needs -- it just won't have its full torque. More than likely you just have the wiring wrong, but if you did have it correct then you probably burnt the L293 when the stepper tried to draw its full 2A of current.

...and so that refers to your questions, but here's your advice:

Using transistors (or an L293, which is transistor based) is using 1990's technology; there are much more modern solutions available. For example, a module based on the DRV8825 is cheap and capable of 2.2A when using a heatsink, but those modules allow you to ramp down the current to keep the heat in check. It really comes down to how much power you need from your stepper motor as to what you should be using but you'd need to give a full description of your project for that type of advice.

 


Robin2

I find it hard to understand how you are thinking of using an L298 if you had read stepper motor basics. Use a Pololu DRV8825 stepper driver. The Pololu A4988 and the BigEasydriver would be struggling with a 2 amp motor and the DRV8825 has a little more headroom.

The title of your Thread is also rather irrelevant to your problem.

...R
Two or three hours spent thinking and reading documentation solves most programming problems.

IsaiasCtz

I find it hard to understand how you are thinking of using an L298 if you had read stepper motor basics. Use a Pololu DRV8825 stepper driver. The Pololu A4988 and the BigEasydriver would be struggling with a 2 amp motor and the DRV8825 has a little more headroom.

The title of your Thread is also rather irrelevant to your problem.

...R
the reason on why im still using the L293b is beacause were i live it aint easy to get a pololu driver, it will get me a month to get it, and i need it quick, so i guess i'll try again with an L299n. :(

Chagrin

Stepstick-style drivers like the Pololu DRV8825 drivers are extremely common in generic versions. If you can tell us what side of the planet you're on someone might be able to point out a local shipper. You might start out by just searching for the keywords DRV8825 or A4988 to find sellers in your area.

IsaiasCtz

Stepstick-style drivers like the Pololu DRV8825 drivers are extremely common in generic versions. If you can tell us what side of the planet you're on someone might be able to point out a local shipper. You might start out by just searching for the keywords DRV8825 or A4988 to find sellers in your area.
I live in Torreon, Coahuila this is on Mexico, i've been searching for distributors and they still kind of far from me.

MarkT

What are you trying to do with this motor?   If you only need slow rotation you should
have bought a high-impedance unipolar stepper and driven with a ULN2803, much
simpler.

If you want high performance from a stepper you just will not get it with H-bridge driver,
you _need_ a current-controlling chopper driver for that application.
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

IsaiasCtz

What are you trying to do with this motor?   If you only need slow rotation you should
have bought a high-impedance unipolar stepper and driven with a ULN2803, much
simpler.

If you want high performance from a stepper you just will not get it with H-bridge driver,
you _need_ a current-controlling chopper driver for that application.
I need to rotate the motor on a slow move, but still need to have a good torque since is going to open or close a curtain, and an ULN2803 only provides 500mA.

MarkT

A high impedance stepper of same torque will take 12V and about 0.4A, and you can
double-up ULN2803 channels anyway as it has 8 and you only need 4 for a motor.
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

yaafm

@IsaiasCtz - what power supply are you using (i.e. Volts and Amps)?

IsaiasCtz

A high impedance stepper of same torque will take 12V and about 0.4A, and you can
double-up ULN2803 channels anyway as it has 8 and you only need 4 for a motor.
I took your advice and buy a ULN2803a, let me give it a try so i get any doubt to ask your for some help.
I´ll keep the post updatws

yaafm

I'll try one more time - what power supply are you using (i.e. Volts and Amps)?

Go Up