RPM counter with PWM

Hi guys,

I am given a mini centrifuge of 6kHz and I am going to make a device to do two things. The first is to monitor and show the RPM of it. the second one is to vary the RPM and the duration of spinning according to user input.

The centrifuge uses a DC 24V brush motor. I have been searching for the methods but still have no idea. Can anyone help?

I am given a mini centrifuge of 6kHz

Do you mean 6000rpm?

I have been searching for the methods but still have no idea. Can anyone help?

Yes you have, it is in the title.
Feed PWM from the arduino to the motor through a logic level FET?
To measure the speed mount a reflective opto switch to the fixed part and paint a white line on the rotating part and measure the time between pulses.

Is this homework?

paullam000: Can anyone help?

Identify the separate problems you need to solve. I can see quite a few, none of them particularly hard. Do your best to find solutions for them all. If you're stuck on any, ask for help. You're more likely to get help from me if it's apparent that you have made a serious attempt to solve the problem for yourself before asking for help.

You're more likely to get help from me if it's apparent that you have made a serious attempt to solve the problem for yourself before asking for help.

Or at least broken the problem down into small enough pieces that show you have a grasp on the project as a whole. Of course, doing that, and looking at the examples, will get you 90+ % of the way without more help.