Motor Control, Would This Work?

[robotcoder]

Would it be possible to control a wheel chair motor with a dimmer switch for speed control and a 3 way switch for forward and backward movement.  If it were possible, then couldn't you have a servo flip the switch from forward to reverse and another servo turn the dimmer switch nob for speed control?

[sonictj]

It may be possible but you are on the verge of a Rude Goldberg. I'd suggest a simple motor driver.  I assume you are trying to avoid the cost of a motor driver, but I think in the end you will find it a better solution.

[airman00]

Would it be possible to control a wheel chair motor with a dimmer switch for speed control and a 3 way switch for forward and backward movement.  If it were possible, then couldn't you have a servo flip the switch from forward to reverse and another servo turn the dimmer switch nob for speed control?

I've seen this system work. I'd still go with a more electronic solution.

[SmAsH]

yup, i would suggest something such as a transistor+relay hooked up to a digital pin on your microcontroller...
or better yet, a motor controller controlled with pwm! that would replace the whole circuit!
not to mention being more reliable than the mechanical counterpart...

please have a look into this. you would need a microcontroller for both, and the electronic solution seems an easier path.

[coolshawn92]

Code: [Select]

yup, i would suggest something such as a transistor+relay hooked up to a digital pin on your microcontroller...
or better yet, a motor controller controlled with pwm! that would replace the whole circuit!
not to mention being more reliable than the mechanical counterpart...
How would this work with just a motor controller controlled with pwm? I am looking to try to control motor shaft direction using a controller and not a motor driver.

[Soeren]

yup, i would suggest something such as a transistor+relay hooked up to a digital pin on your microcontroller...
or better yet, a motor controller controlled with pwm! that would replace the whole circuit!
not to mention being more reliable than the mechanical counterpart...

How would this work with just a motor controller controlled with pwm? I am looking to try to control motor shaft direction using a controller and not a motor driver.

It wouldn't, unless the controller has got an in-built driver. A motor driver is what goes between a controller and a motor to put out the needed current.

[coolshawn92]

It wouldn't, unless the controller has got an in-built driver. A motor driver is what goes between a controller and a motor to put out the needed current.

I have a motor driver and a controller. The motor runs fine with the 50 A controller, but I am looking to change the direction of the shaft using my motor driver and controller. Can this be done?  Like a a way to wire the circuit so after or before the motor goes through the controller it knows what direction to turn.

[Soeren]

Hi,

A little hard to say when you don't give the make and model of the driver/controller.
Didn't the equipment come with a manual?

[coolshawn92]

Didn't the equipment come with a manual?

No, they just came with a piece a paper showing each component of the board.

Here are the links to the devices on sparkfun.com

http://www.sparkfun.com/commerce/product_info.php?products_id=9950

http://www.sparkfun.com/commerce/product_info.php?products_id=9668

http://www.sparkfun.com/commerce/product_info.php?products_id=9107

Thank you

[Soeren]

Hi,

No, they just came with a piece a paper showing each component of the board.

Here are the links to the devices on sparkfun.com

You can download datasheets from SparkFun.

http://www.sparkfun.com/commerce/product_info.php?products_id=9950

This is just a microcontroller board.

http://www.sparkfun.com/commerce/product_info.php?products_id=9668

This one seems to be unidirectional - a DPDT relay that can handle the current could make it bidirectional.

http://www.sparkfun.com/commerce/product_info.php?products_id=9107

This one is bidirectional.

[Libraoct7]

Ok I just built the $40 Line Follower. All lights are glowing but motors are not working. No current coming to the motor wires. Could this be a problem with the controller I got. I used L293NE. Is there a difference between L293D and L293NE?
Please help me this is my first project for my school and there isn't time left to hand in the project. Thanks to all.

[coolshawn92]

Yes, they I know the Motor driver is bidirectional but I also need the motor controller to limit rpms of the motor's shaft. I was just wanting to know how to connect the motor driver and controller together so I can limit the shafts speed and using both directions.

[Soeren]

Yes, they I know the Motor driver is bidirectional but I also need the motor controller to limit rpms of the motor's shaft. I was just wanting to know how to connect the motor driver and controller together so I can limit the shafts speed and using both directions.

Perhaps it would be a good idea if you clearly defined what you call the motor driver and what you call the motor controller.
You have one (Arduino) microcontroller board, one (15A) H-bridge motor driver and one (50A) unidirectional motor driver and I am not sure I follow what it is that you want to do.

It wouldn't hurt either, if you downloaded and studied the datasheets for each of them.

[coolshawn92]

I have just discovered that I will not be able to interface the two (or at least that I don't know how). I am now looking for other options. Since being able to change the direction of the shaft is more important, I have decided to just stick with the motor driver 15 A. But the RPMs are just too great. Is there a way to decrease the output voltage and hopefully that will slow down the rpms?


Thank you for your time.

[Soeren]

Hi,

But the RPMs are just too great. Is there a way to decrease the output voltage and hopefully that will slow down the rpms?

Yes, use PWM for the output and you can control the speed.
If the motor RPM is much higher than you need, gearing down might be better, but PWM allow you to have as good as any speed between 0 and max. RPM.