Guys, Regarding to stepper motor... I thought I could use it for Autothrottle, and fortunately I purchased this stepper motor through internet where it has such few information along with color of wire to the windings, here is the diagram of stepper motor.http://forums.avsim.com/user_files/11645.txtNow I was told that stepper motor can be connected directly to output module, but sadly to say this, I wouldnt know which 8 of wire would be necessary to connect with stepper motor. I suppose I could get somebody to help me out getting me understand the connection between stepper motor's 8 wires to the 32 points output modules. Let me know

Below is a link to site with some basic information on Stepper motors. http://www.doc.ic.ac.uk/~ih/doc/stepper/others/It appears you have a 6-wire unipolar stepper motor. The following may help you:1) You have a motor with 4-coils. By powering one of the 4 coils, you can move the motor 1/4 turn lets say. If you power the next coil in sequence, the motor will move another 1/4 turn, and so on and so on. Also, if you power the coils in the reverse order, the motor will run in reverse.2) To use this stepper motor as an autothrottle, I would attach 4 miniture relays to one of 4 outputs on my output module, and then attach one stepper motor coil to each relay. You need to pick a small/fast relay so they don't interfere with the realism of your autothrottle.3) To use the autothrottle, all you have to do is activate the outputs of the Output Module in the correct order, forward or reverse and the stepper motor (and whatever is attached to it) should follow.The caution I would give is to make sure you know the voltage/current ratings of the stepper motor and the relay you use.Good luck.

Jam01, Thank you for replying, I would say I understand the basic concepts on your statement about stepper motors. But the only thing I dont understand is the connection between stepper motors to the output modules. Do I need to have power supplying into stepper motor? >2) To use this stepper motor as an autothrottle, I would attach 4 >miniture relays to one of 4 outputs on my output module, and then >attach one stepper motor coil to each relay. You need to pick a >small/fast relay so they don't interfere with the realism of your >autothrottle.At which type of miniture relays would I need for connecting the output? would that be Power, DPDT, DPST, SPDT, SPST, REED relays? Say care to explain me the function of relay that wouldnt intefere with realsim of my Autothrottle? Wouldn't it be matter on which coils of output that connects relays? do I need to connect at speific coil output? Since I am a little bit confused on the conncections, I thought if you could go through a diagram of winding schematic that I attached earlier which indicates the coil output's numbers. If you can just label out on which coil's number sshould relays be connected with, I would have got a better understanding.3) To use the autothrottle, all you have to do is activate the outputs of the Output Module in the correct order, forward or reverse and the stepper motor (and whatever is attached to it) should follow.I am not sure which sequences I would get it in correct order. Are there any guides or a good picture explaination that I would get to know which ways they are? Perhaps could you explain the examples?Again Thank you for replying back

BusyBee:I would need more specific information about the actual stepper motor to help. At a minimum, I would need the actual manufacturer model number so I could help you find the required voltage.If you know the voltage, post it. If you don't know, you should contact the source of the stepper motor to find out.I'll draw you a schematic to show you the connections as I understand them.

Hope this picture helps.It assumes your stepper motors require +5vdc and that the relays require +12vdc. If your stepper motor or relays have different voltages, simply change the voltage supply accordingly.Now to answer your questions:1)But the only thing I dont understand is the connection between stepper motors to the output modules. Do I need to have power supplying into stepper motor?Yes. You can see this in the attached jpeg file.2) At which type of miniture relays would I need for connecting the output? would that be Power, DPDT, DPST, SPDT, SPST, REED relays? You'll need at least an SPST. I use a DPDT in my diagram, but that is overkill for what you'll need. I suggest you use a SPST.3) Say care to explain me the function of relay that wouldnt intefere with realsim of my Autothrottle? If you use large slow relays, they might be too slow to allow the stepper motor to move as fast as you would like. Please understand, the motor will only move one complete rotation as fast as your four relays can cycle through. This may not be a problem, but I want you to consider it.4) Wouldn't it be matter on which coils of output that connects relays? do I need to connect at speific coil output? Since I am a little bit confused on the conncections, I thought if you could go through a diagram of winding schematic that I attached earlier which indicates the coil output's numbers. If you can just label out on which coil's number sshould relays be connected with, I would have got a better understanding.Yes, you do need to connect specific windings to specific outputs. See the attached file, I think it's correct for your stepper motor.5) I am not sure which sequences I would get it in correct order. Are there any guides or a good picture explaination that I would get to know which ways they are? Perhaps could you explain the examples?You can search the internet for the NEMA23ESM and see what documentation you can find. The diagram I created is based on information I got off the internet.Hope this helps.

JAM01: This steppermotor is Manufactuered by AIRPAX and it has a 5 volts, 7 watts, 15 degree step. 8-Wire Unipolar (there are two sets of indentical wires from the winding diagram number 2 and 5) let me know if this did supply you enough information about my stepper motor.

Check my post #4, it should be perfect for your needs. It has the wiring diagram and has the correct voltage also. It also answers your earlier questions.Now all you need to do is purchase 4-12vlot dc relays, 4 diodes, and wire it up.Good luck.

I think the diodes across the relay coils are in backward.Mikewww.mikesflightdeck.com

Mike:You're absolutely correct. I haven't used a relay in over 10 years, I guess my age is catching up with me.Here's the correct orientation.

JAM01, That's picture perfect! I dont know how to thank you... but Thank you JAM01, I really appreicate that for trying to help me out with stepper motor connections. You did great job in drawing, also provide great information. I wish I could get that started today, but unfortunately I dont have any of miniture SPST or DPDT relays, I only got large DPDT. I have tried through radio shack, unfortunately miniture spst its out of stock. Well what I will do is start ordering them tonite from digikey, jameco, or any kind of electronics dealers, as soon as i get it working I will let you know how it does.If you use large slow relays, they might be too slow to allow the stepper motor to move as fast as you would like. Please understand, the motor will only move one complete rotation as fast as your four relays can cycle through. This may not be a problem, but I want you to consider it.Duly noted... so it based how much torque does stepper can give? Now I realize this 'NEMA23ESM' is unipolar stepper motor... assume it means only one polarity... so does it goes one direction if I wanted it to go both driection (foerward/backward)? since Mike proposed that the diode between relay coil is in backward? I think he is right. But I dont know for sure. = )

Yes Mike was right on the diode direction, so I posted a new picture with the correct direction.Also, the stepper motor will go backward if you energize the coils in the reverse direction.For forward, use Outputs 1 then 2, then 3, then 4, then 1 ....For reverse, use Outputs 4, then 3, then 2, then 1, then 4 ....Good luck....back to testing for me.

Here's the R&R solution for the stepper motor, including the EPL software to drive the motor.http://www.mindspring.com/~rrelect/epic/USB/usb_examples.htm

In regards to using relays to switch the motor windings, you might want to consider using low-power triacs. (SCR's would work, but using a triac you won't have to worry about Anode/Cathode polarity)TRIAC,2N6071A,4A,200V Jameco #140425 Mfg Ref # 2N6071A www.jameco.comThis triac requires a 5VDC bias on the gate, which is good for this type of application. Eliminating the mechanical relays also eliminates the poor switching transition times, allowing for a near-instantanious current switching on the stepper motor.

Are you refering using triac instead of using relays?? What a interesting kind components would do this functions. A similar looking with voltage regulator type. To be honest, with my experience into electronics for few years, I have not seen or ever heard of this type of components. how would I connect all 3 terminals? diodes, or just wire straight from stepper motor.. Let me know. As far, I am Using PC SPDT relay manufactured by ormon, I was told that it can do instantaneous bi-polar direct current based on command I can give out at value at approxmately 50 microsecond maximum in refering to gigahertz pc types. But I have not yet tried on some experiment with EPIC. Since its so cheap to buy this component, I could try to order those, build the circuit and do some experiment on it and see if that would be quicker than the relay circuits.

Hi Ray,I agree that some sort of power semiconductor is a probably a better choice for driving a stepping motor than a relay. However, using an SCR or triac in a DC powered application may be more trouble than it's worth. These devices remain in an off state until triggered by some gate current, then remain on until the load current drops to zero. Typically, SCRs and triacs are used in AC load applications because the periodic reversal in voltage polarity causes the load current to pass through zero, and the device conveniently turns off. In a DC situation the designer has to add additional circuitry to force the load current to zero so the device will turn off. Certainly possible, but it means added complexity.Depending on the power requirements of the motor an integrated driver like an L293D or a discrete H-bridge using components with higher power ratings might be a simpler solution.Mikewww.mikesflightdeck.com