Using Stepper Motor Driver to run motors

[duluk12300]

Hey guys! I'm a newbie and need some help with a project i am working on to my car actually. Some lexus headlights move up and down by stepper motors, and i want to incorporate them into my car.

I bought some lexus headlight stepper motors but have no idea how i can get them to work.

Basically, they work by a stepper motor in each headlight. The motor has a small piston that moves up and down. when it moves up, it pushes the headlight pojector in one direction. when it moves down, it pulls the reflector in the opposite direction.

I just need to figure out how to control the motors by using some sort of potentiometer.

I want to have some sort of a potentiometer where...

-rotating to the right would push the motor all the way out
-rotating all the way to the left would pull the motor all the way in
-with the rotation in the middle, the motor pushed half way out

please see this link on a lexus forum where it explains more about what i am trying to accomplish:

https://www.clublexus.com/forums/showthread.php?t=359568

Thank you for any advice!

 

[duluk12300]

anyone? =/

 

[HarveyH42]

I never got my '84 Firbird pop-ups to work, just left them up manually. They used gear motors and several relays. Kept the motors when I scrapped the car. Pretty good torque. Kind of curious why Lexus would use steppers instead of gear motors...

A pot might work, but a rotary encoder would be a better choice, like in a mouse.

 

[duluk12300]

thanks for that advice!

How could i incorporate one of those into a circuit to get these motors to work?

 

[HarveyH42]

The only pot in that Ramsey kit, is for speed control. There are three button switches, one power, one forward/reverse, one run/pause. You would need 2 of these kits. With 4 leads to the motor, tells me its a bi-polar stepper. There are many circuits on the web, even some controller chips (ULN293).

 

[duluk12300]

basically what i want to do is convert those button switches into one potentiometer.

If the pot is rotated clockwise i want the motor rod to be fully extended
If the pot is centered i want the motor rod half extended
If the pop is rotated counterclockwise i want the motor rod fully withdrew.

Are there any circuits already made for something like this?

 

[HarveyH42]

I've seen a servo motor driver like that, but not a stepper. I doubt you'll find something like that for a stepper motor, not a real logical choice. Search for 'Stepper Tutorial', there is a web site that will tell you how a stepper motor works, and what you need to make it turn. From that, you should understand why your request is so unusual. The pot will change a voltage level, not real useful for the stepper. Steppers are more digital, the coils are either energized or not, the sequence decides the direction.

 

[mashersmasher]

it might be allot easier to use a couple of servos and a cheep pic