Stepper motor problem ..

[pv.aditya]

Hi everyone ..

I have a stepper motor that of a local manufacturer.. unipolar,5-wire,with a requirement of 12v and 400 mA .. I have used two driver IC's L293D and ULN2004A to make it run and am unable to do it ..

I dont know if it is working or not ? I tried the connections as in the following link

Stepper Motor interfacing with Microcontrollers tutorial: Connecting Stepper Motor : 8051 Microcontroller Projects AVR PIC Projects Tutorials Ebooks Libraries codes

but everything in vain ..!

I have found the usage of LED to make it glow while rotating the shaft and drawing the conclusion that the stepper motor works ?? Is it the correct way ?

and like DC motors ; can we test the stepper motor directly by connecting the DC adapter to it ..? I even tried this but couldnt make it run !


So please say me ways to make it run ! Are driver IC's necessary to make it run ? Can't we run the stepper motor by providing necessary voltage and current rating ? What other factors should I consider and what all information should I know about the stepper motor ?

Awaiting your reply ..

---------- Post added at 19:40 ---------- Previous post was at 19:33 ----------

The resistance of live-live wires 145.12 ohms and that of live and ground wire is 72.55 ohms ..

 

[alexan_e]

If you have a power supply of 12v and is able to provide at least 400mA then you can connect the gnd to the common wire and then the positive to any of the other four wires (you can swap the polarity if you want, it doesn't matter), you should get a small movement each time you feed a different wire (which feeds a different coil).
Are you sure that you are using the correct common wire, check with an ohmeter the resistance you get.

Alex

---------- Post added at 17:19 ---------- Previous post was at 17:15 ----------

The resistance of live-live wires 145.12 ohms and that of live and ground wire is 72.55 ohms ..

if this is a 12v/400mA motor I would expect 12v/0.4A=30 ohm
the reported 72 ohm would allow a current of about 166mA, if this means that the specifications of the original post were wrong then there is no problem but if this is in fact a 12v/400mA motor then the coil resistance is not what it should be.

Alex

 

[pv.aditya]

Hi Mr.Alex,

I might be wrong in specifying the exact current rating ..but the rest of the details abt the resitance and the voltage rating are correct.. As the one's i bought were from a very local company from my place, I didnt even found out any data sheet .

So far i have tried out all the connections but wasnt able to move the shaft of the motor even a bit ..

And what is the voltage to be provided to the controller pins of the driver IC ..? I actually provided !'s and 0's from the supply of 12v and ground respectively.. I am a noob at this. This is the first time I hve come across stepper motors and am lost .

Few mishaps happened so far ..

1. both the driver IC's ULN2004A and L293D , got burnt along with the breadboard at the controller input pins.. and once at the output pin number 14.

 

[alexan_e]

If you check the L293 datasheet you will see in page 4/5 that the maximum allowed input voltage is 7v, you can't use 12v.

I would suggest to remove all the chips and try directly with the power supply as I have described in the previous post, if the motor doesn't move then it is probably damaged.

Alex

---------- Post added at 19:12 ---------- Previous post was at 19:09 ----------

another note is that L293 can output 600mA so why are you using the ULN2004?
And why have you used two L293?

The schematic is quite simple

 

[pv.aditya]

yes Mr.Alex. I tried it just now . It wasnt rotating .. But I read in a website that if the resistance of combination of two live wires is double that of live-ground combination, then
that motor is working. How far can this statement be true.. ?

I have bought 4 stepper motors & I dont think all the 4 motors are defective. ?

 

[alexan_e]

Actually the power supply in the above schematic is nor correct, the logic supply (pin16) and EN1 and EN2 should be connected to 5v (and then use 5v control signals in the input), pi8 is the output supply and should be connected to 12v.
So in a few words in the above schematic invert in 8 with pin 16 and also invert the 5v and 12v

the correct supply is as shown here

---------- Post added at 19:25 ---------- Previous post was at 19:22 ----------

if your motor is OK and your power supply can provide the needed current then the motor will rotate if you connect the supply directly to the coils.
If you connect different ends you should see small movements unless you have a geared motor which needs many steps to move a slight amount.
Do you have any link or image of your motor?

 

[pv.aditya]

**broken link removed**

Sir, this is exactly the type of stepper motor I have used ..

Firstly, I want to ask you a question ..

are the driver IC's able to drive UNIPOLAR motors too .. I have read that L293D is used for unipolar and bipolar too...!!

 

[alexan_e]

Your motor is 12V, 160mA as the resistance had suggested too and is not geared so you should see it moving when you feed it directly from the power supply.
if you can't make this work then I don't see the point of trying to make it work using additional circuits.
Connect the common wire to + or - and then connect the other supply wire to any of the coil ends , there should be a slight move , then connect it to any of the remaining the coil ends and it should move again.

The L293 is able to drive a unipolar motor but maybe it would be easier for you to use the ULN2003

 

[pv.aditya]

I guess all the 4 motors arent working ..! I have just tried it and the outcome is NIL ..!!

but am able to see the LED glow when i connect it to the wires and on rotating the shaft..! Its the only factor that is still making me hopeful about its working !

 

[alexan_e]

are you sure that you are using the correct common wire, does it have a different color?
What about your power supply, can it provide the current? (it is 12v?)
When you connect the supply to any of the coils and try to turn the motor with your hand do you feel it resisting?
The movement that you should see is just 1.8 degree are you sure that you are not missing it because you expect it to move more?

 

[pv.aditya]

Mr. Alex, I am using the power supply of 12v, 800mA . And the wiring is not coloured. Its just the way as u see in the link I have provided above. I have checked everything. Am working on it since a week Sir . I am just stuck at this place and couldnt proceed further.

 

[kak111]

can we test the stepper motor directly by connecting the DC adapter to it ..? I even tried this but couldnt make it run !
So please say me ways to make it run ! Are driver IC's necessary to make it run ? Can't we run the stepper motor by providing necessary voltage and current rating ? What other factors should I consider and what all information should I know about the stepper motor ?

A Stepper Motor or a step motor is a brushless, synchronous motor which divides a full rotation into a number of steps.
Unlike a brushless DC motor which rotates continuously when a fixed DC voltage is applied to it, a step motor rotates in discrete step angles.
And it needs exactly controlled sequence of coil currents.


Have you read all the parts here..............

Introduction to Stepper Motors
Step Sequence of Stepper Motors
Stepper Motor Connections
Programming for Stepper Motor

Read all first
Stepper Motor interfacing with Microcontrollers tutorial: Introduction : 8051 Microcontroller Projects AVR PIC Projects Tutorials Ebooks Libraries codes


Look these too...........

How Stepper Motors Work : 3 Parts 2 Videos
**broken link removed**

Quick Start for Beginners to Drive a Stepper Motor
**broken link removed**


**broken link removed**

 

[alexan_e]

When you connect the supply to any of the coils and try to turn the motor with your hand do you feel it resisting and locking to a specific step position?

 

[pv.aditya]

mr.alex,as u said,motor is resisting the movement after giving connections.and this is happening with all the 4 motors i've got

 

[nandhu015]

I doubt your powersupply.

What powersupply are you using?

 

[alexan_e]

mr.alex,as u said,motor is resisting the movement after giving connections.and this is happening with all the 4 motors i've got

then it should move as well as you move the power supply between different coils...
Are you sure that if you notice carefully there is no movement?

 

[pv.aditya]

ac dc adapter
iinput: 100-300v AC
output-12v DC 800mA

I HAVE CHECKED IT WITH THE MULTIMETER AND IT IS PERFECTLY ALL RIGHT !

---------- Post added at 22:41 ---------- Previous post was at 22:38 ----------

@Mr. Alex, Yeah sir .. it doesnt run !

---------- Post added at 22:50 ---------- Previous post was at 22:41 ----------

Hey .. i finally got the movement .. Thanks to everyone posting.. and especially to Mr. ALEX. actually the stepper motor have got stuck ..dont know its reason.. But when i
applied grease at its shaft and made it a bit free.. I observed its movement..!

Am really sorry if I eve troubled u Sir. U helped me a lot.. Thank You

---------- Post added at 22:53 ---------- Previous post was at 22:50 ----------

Thank you Sir. This forum rocks

 

[KHALEDRAHNAMA]

The problem solved , but I want to teach every one a good way to check any DC or even some Ac type motor function by simply connecting your MM to the motor's wires and turning the shaft with your hand , you should see some voltage that change with your turning speed
Good Luck.

 

[pv.aditya]

yeah that helps

 

[bigdogguru]

Here's an informative video demonstrating how to test, determine type and wiring configuration of a stepper motor using only a multimeter and a battery.

Hope the video helps.

BigDog