4 wire motor driving linear action, making bomb prop.

Other Hardware Motors, Mechanics, Power and CNC
1

Hello everyone,

I've been given a motor to build into a project i'm working on to make a fake bomb. I've got the whole process working, from wire test, through to a solenoid popping balloon. (here's the lovely little sparkfun display doing it's thing: DesignersFront.com is for sale | HugeDomains )

I just can't get the motor to work. I've tried a few tutorials, and I've wired up a couple of motors before (typically steppers), using this H-bridge and the texas instruments SN754410. It makes me realise I perhaps don't even know what I'm on about. What are the four wires on this motor actually doing? Does anyone recognise this motor, know where to find a datasheet?

I've tried wiring up as recomended here: http://luckylarry.co.uk/arduino-projects/control-a-dc-motor-with-arduino-and-l293d-chip/

and with the SN754410 using an external power source.

As you can see from the attached image it came with a motor driver circuit already wired that they informed me worked fine with it, but I can't see where to put the external current in, as all four corner pins are connected to 5v on the arduino.

Code wise I've just been trying combinations of writing the four pins high and low, with very little effect. I have been able to get it going forward jerkily a few times, but not really been able to make sense of whats happening. Do I need PWM or perhaps are the wires doing something more complicated than just back and forward?

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2

What is the motor? That's a key question!

3

Yes, exactally. :~

There are no markings or codes to identify it, I presume it isn't a steeper because of it's size. All I can offer is the image thats attached. If it's a normal DC motor, then why four wires? Thats far more typical of a stepper isn't it?

What it does is move a central column back and forwards, and apparently can do with control over the speed (again, stepper) or perhaps using PWM, but then why the four wires.

4

Working, was just fine using stepper library. The fault was in a couple of touching contact points.

5

Well hard drive spindle motors are 4-wire and they are 3-phase brushless motors so it could have been something 'exotic' like that.