Amiga.org

Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: trekiej on February 09, 2007, 03:52:17 AM

Title: Stepper Motor Question
Post by: trekiej on February 09, 2007, 03:52:17 AM
I do not know if this is the right place to post.

I have a stepper motor, and I do not know if the specs. are right.  The data sheet says 180 mOhm res. and I get 600 m Ohm resistance.  Some of the dimensions are wrong too.
Its number is a 110BYG450C.  Sad enough, the dealer can not help me.  They offered me the chance to return it.  I may do so.
Its Jameco number is 237585.

I do not know if it is a constant current or a constant voltage item. The specs. seem to point to constant current.

Thanks.
Title: Re: Stepper Motor Question
Post by: JaXanim on February 09, 2007, 11:35:12 AM
Why don't you ask them? (http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&productId=237585)
Title: Re: Stepper Motor Question
Post by: rkauer on February 09, 2007, 05:42:37 PM
I could only give a physics lesson: you could't read impedance directly from a multimeter!

Impedance isn't just resistance (DC measure of a circuit).
It's a formula, calculated when the circuit is under AC current/voltage:

Z=U/I , where

Z = impedance, in Ohms
U = potencial difference (=voltage), in Volts RMS
I = current, in Àmperes RMS

Need to say the Z change under different frequencies, in most of the cases. Only PURE resistors don't change impedance over different frequencies (R=Z).

Maybe I'm just teachy, but maybe helps.
Title: Re: Stepper Motor Question
Post by: trekiej on February 09, 2007, 08:10:47 PM
I talked to them 3 times already.
I will take it to school next monday and use their inductance meter.
I still may send it back.
Thanks.
Rick.
 :-)
Title: Re: Stepper Motor Question
Post by: trekiej on February 11, 2007, 12:04:56 AM
I was able to get it to step by using a wall transformer.
It was rated at 6 VDC and 300 mA.  My meter said it was 14 VDC. : (
I found out that it can be used as a unipolar and bipolar motor.  In bipolar configuration it can be series or parallel.  The information is not for the exact motor so I have to be cautious.

Thanks.
Title: Re: Stepper Motor Question
Post by: AMC258 on February 11, 2007, 12:19:29 AM
You can read impedance from a multimeter, you just have to have an AC source instead of the usual DC source that's inside the meter.
I often do this with a signal generator and a VTVM to check high current motors where the Resistance is <1 Ohm, but the Reactance is rather high.
Title: Re: Stepper Motor Question
Post by: weirdami on February 11, 2007, 12:59:58 AM
@trekiej

What is it you are trying to get to steppin' with a motor that size?
Title: Re: Stepper Motor Question
Post by: trekiej on February 11, 2007, 02:21:39 AM
Hello.

@ weirdami

I am building a plasma/cutting torch rig.
It will be about 10' x 5' x 2' in size.
I  am working toward being an Industrial Electrician.
This is one of a few machines that I want to build.
The motor is about 1/3 to 1/2 of the pictured size. ( on spec sheet)

XL = 2 pi F L
I need to check on what frequency would be the best.
My multi-meter works to about 400 hz. (darn meter)

 : )


Title: Re: Stepper Motor Question
Post by: DamageX on February 11, 2007, 07:09:33 AM
Quote
It was rated at 6 VDC and 300 mA. My meter said it was 14 VDC. : (

Wall warts usually read higher than the rating. The voltage will drop under load, plus it's probably meant to go to a regulator anyway.
Title: Re: Stepper Motor Question
Post by: trekiej on February 11, 2007, 05:54:41 PM
@ DamageX
I was wondering if that was the case. I did not have a Load to test it.  I found out basically what I needed.  I did not pursue it more. What is your electrical experience?
Thanks.

Title: Re: Stepper Motor Question
Post by: rkauer on February 11, 2007, 07:11:07 PM
You could use an ordinary regular lamp as load. Put it in the output PS and then read the voltage in the multimeter.

A good regulator for a very wide range aplications is the 78xx series (but its maximum current is 1A). All do you need is a 7806 and two caps AFTER the regulator: a electrolithic  about 470uF, and a ceramic one (100 nF is enough).

Need a diagram?
Title: Re: Stepper Motor Question
Post by: trekiej on February 11, 2007, 09:26:33 PM
I have a 7805 that I could use.  I do not know if I am giving it the right power.  I hear PWM is a way to get the right Amps with higher voltages.
I need to learn more about chopper power supplies.
I do not need a diagram, thanks.
I am getting closer to putting this thing together.
My family had more concrete poured and it will be soon that we move the machines around.

Title: Re: Stepper Motor Question
Post by: Daedalus on February 11, 2007, 10:25:01 PM
If I were you I'd look at getting a stepper motor driver module. They can usually run off an unregulated supply of any voltage from 12 to 30V, are fairly universal so will be able to run pretty much any bipolar motor in series or parallel, and take simple logic inputs for step, direction, hold signals etc. I used them and two stepper motors to automate a telescope and they were great. Take care of all the PWM, current limiting correct phases of the coils and so on...
Title: Re: Stepper Motor Question
Post by: trekiej on February 12, 2007, 12:25:12 AM
I am low on the funding right now.
I hope to finish up a book on Linear Electronics.
I need to finish the semiconductor and OP Amp sections.
I wish I had bought a motor with clearer specs.
I like my supplier but they let me down this time.