Automatic speed control of dc motor from ac supply

That sounds like an interesting project that could be a lot of fun! However, please keep in mind that we are not a free design or code-writing service. We’re more than happy to help with your design or code, but we need you to make an initial attempt. Please design and write your code, then post it along with an explanation of what’s not working properly. There is also a for hire section if you want to pay for it.

I would assume the teacher/professor expects you to learn how to do this and understand what you did. This is basic material and if you do not master this you will have an increasingly difficult time.

  1. Show Your Work First: Before asking for assistance, make an attempt to design or write the code yourself. Share your work along with details about what isn’t working. That includes a preliminary schematic that you drew.

  2. Provide Clear Documentation: Since we can’t see your project, share an annotated schematic (best) or a clear drawing of your setup. Clear Pictures are welcome, but avoid using Fritzing diagrams as they are wiring diagrams, not schematics, and are not ideal for troubleshooting.

  3. Include Technical Details: If there is specific hardware involved, include links to technical information. There are often many versions of similar components, so precise details are essential. Many times the processor is assumed, please state which one and post a link to it.

  4. Reference Resources: For additional help, check out useful links and tutorials: Useful Links on Arduino Forum. Of course one of the better sources of information (in my opinion) is the Arduino Cookbook. Skim it cover to cover and stop on any project that interests you.