Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Voltage step up

Voltage step up

Voltage step up


I'm working on a project where I need to control the speed a dc motor (basically controlling the speed of a small car). This controlling of motor speed has to be done based on the ldr values. I'm using arduino board to read ldr values and based on those values im sending analog signals. But the volt of this varies and is less then 3 volt. I need -+9V to make the motor working. Can you please tell me how can i do this. I have tried step up but for some reason it is not working. i guess because the voltage is analog(varying), i dont know!

Baseline is, I'm using ldr to control the speed of the motor and using arduino to do it. The output im getting from arduino is 3v and i need 9v for motors to be running.

Your help would be appreciated!

RE: Voltage step up

Use a 9 volt motor controller with a 9 volt supply.
Use the Arduino to control the motor controller.

Ohm's law
Not just a good idea;
It's the LAW!

RE: Voltage step up

Convert the analog to PWM inside the Arduino and output that signal. Feed it into a motor controller board that takes a PWM signal. You can get a small board cheap that will do this from Ebay or Amazon.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close