Stepper motors (2)

Hello everybody,

I want to add a motor to my webcam to be able to turn it remotely and I want to do this out of spare computer parts, if possible.

I've obtained a 4 phase unipolar stepper motor from an old floppy drive, which's specs go like...

kp39hm2-025 12V Unipolar 4 phase 1.8 degree stepper from Japan servo Red = Common Bl = Phase A Ye = Phase B Br = Phase C Or = Phase D

I was thinking of hooking it up to a parallel port and then controlling it programatically (sending the voltage to the wires is something I would know how to do once within the computer).

Now I know the parallel port provides me only 5V and that the motor is

12V but I suppose even an underpowered motor would still turn (I've run 24V installation fans in my computers on 12V and they worked just fine).

Now I've found a post from this newsgroup saying:

...Steppers are produced in two kinds: one is unipolar 4 phase - it has 5 wires, 4 coils with one common connector. common you hook to +5V and switch the ground between the four others...

I realize the Parallel port would in effect have it the other way around (one ground and voltage on the wires).

Would this ever work?

Probably not, so which components would I need to get myself to get this finnished anyway as cheap as possible?

Thanks in advance.

Reply to
Jure Sah
Loading thread data ...

All you need is something like a ULN2803a Darlington driver chip, plus the connector and cable for the parallel port of course. The chip costs about 40p in the UK, I guess less than a dollar in the US. Here is the data sheet:

formatting link
I could probably provide a circuit diagram diagram if needed, but it is a very simple circuit.


Reply to

formatting link
has some simple circuits that should boost your port enough.

formatting link
is one example of a really simple unit.

Please note that none of these are "microstepping" controllers. Microstepping smooths out the motion of the motor so that your camera will not "jerk" from one angle to the next. If that is important, may I suggest our Linistepper design? It is open source but also comes as a kit, or bare PCB:

formatting link

Reply to
James Newton

I saw a fun looking microstepping chip by Japan Radio or something like that, 'phoned for samples and spoke to a very helpful man who took all my details and then said it would take about 4 months to get them.

Whoopee :o(

Reply to
Robin G Hewitt

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.