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SI 7300 Stepper motor driver Circuit

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Newbie level 4
Jan 29, 2006
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46si stepper

I have a stepper motor salvaged from a printer. I can see that it draws 1.3A/ph. I also salvaged SI 7300 chips from it.
I am trying to drive the motor with that chip, but fail to do so...
I dunno y. The power supply to the chip was 12V 3A.
I want to know wheter this didnt work coz of this low voltage!

I am sure that both motor and the driver chip works!

Can somebody Plz help me!
r does someone have the circuit which uses 7300 ??

Thanks in advance!

What are you using to produce the excitation signals?
The SI7300 only contains the drivers, but you need to generate the signals from another device, usually a micro.

I manually excited at 5 V by using a voltage regulator

In that case it is very hard to tell if the motor is moving, given the small step size.
Can you hook it up to a micro? Or at least an oascillator and some FF's ?

You really need to generate step and direction signals with either a micro or a 555. With the 555, generate a couple 100 hz square wave and then manually switch directions.

Also, make sure you've got the coils properly wired. You can tell which leads go the same coil by shorting them together - if the motor is harder to turn by hand then they are to the same coil. If its a unipolar motor then you will need to figure out the center tap.

By the way, with "manual excitation" (sounds kinky...) you should at least get at least a small jerk


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