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Automated DC or Stepper Motor Forward/Reverse/Brake

BiomedEngineer

Nov 14, 2012
3
Joined
Nov 14, 2012
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Hello all!

I am fairly new to circuit design, I have some background but not too much. What I need is a pretty simple circuit to control a DC or Stepper motor. The motor needs to go in clockwise position to screw in a screw shaped device. Once the screw is in it will need to stop automatically (proximity sensor?). After an adjustable amount of time (around 30 seconds) the motor will reverse and unscrew and stop automatically. This will repeat for a series of about 5-7 days to give you an idea of how robust it must be.

The screw will be pushing a rod by screwing in. This will be a very small amount of load (max 2 lbs, probably a lot less). The screw will travel about 1 in. The screw has not been designed yet so threads can match design. This will have manual stops so there would not be a risk of screwing too far, but I wouldnt want the motor to burn up. Speed is flexible as well.

I am not really sure the best way to achieve this. I have looked into 555 timers, DPDT relays, and H-bridges. I am not against off-the-shelf products and price isn't too big of a concern.

For now I would just like something that screws in then stays stopped for 30 seconds then unscrews stops and stays stopped for 30 seconds. This would repeat by itself until turned off. Once I get a working prototype I would like to be able to vary the time that motor stays stopped but that is for later. :)

Any help would be appreciated!

Thanks. :D
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
Joined
Jan 21, 2010
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25,510
If you know exactly how many revolutions you could use a stepper motor to turn it a certain amount in one direction and back again in the other.

It would be a fairly simple program on a microcontroller interfaced to a stepper motor driver.
 

BiomedEngineer

Nov 14, 2012
3
Joined
Nov 14, 2012
Messages
3
If you know exactly how many revolutions you could use a stepper motor to turn it a certain amount in one direction and back again in the other.

It would be a fairly simple program on a microcontroller interfaced to a stepper motor driver.

What if I wanted to eliminate the use of a microcontroller and strictly have a black box with a power switch, 2 dials (1 for delay after screw in and 1 for delay after screw out)?
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
Joined
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Messages
25,510
You can't get much blacker than a microcontroller.

Seriously, you know what a black box is don't you? It's a device that performs a specified function, but one which you don't know (or don't care) what's inside.
 

BiomedEngineer

Nov 14, 2012
3
Joined
Nov 14, 2012
Messages
3
You can't get much blacker than a microcontroller.

Seriously, you know what a black box is don't you? It's a device that performs a specified function, but one which you don't know (or don't care) what's inside.

Sorry I misunderstood what you were saying. I was thinking that you meant it would have to be hooked up to a pc at all times. I'm looking into picaxe.
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
Joined
Jan 21, 2010
Messages
25,510
Yes, a picaxe would be ideal
 
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