can the arduino unit time relays by reading a laser input from a spinning wheel?

Projects General Guidance
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Hello I am hoping for some tips and perhaps advice here as to whether the arduino unit (or perhaps which unit) would suit my needs. In a nutshell, I need to switch 6 relays on and off (it will be DC current but not sure how many volts yet) and the timing needs to be determined by the spin speed of a rotor which could be read by a laser, perhaps even a mouse could suffice. So if the arduino can do this how would it best be set up?
Much Thanks
Kai

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I need to switch 6 relays on and off

Any Arduino can do that, provided the relays (or transistors) draw little enough current.

and the timing needs to be determined by the spin speed of a rotor

I'm not use that I understand this. How does speed of the rotor determine when to turn a relay on or off?

What kind of speeds are you talking about? One revolution per week or 30,000 rpm?

which could be read by a laser

I'm not sure that a laser, which is an output device, can read anything.

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Hi Paul
thanks for your reply. well the inner rotor houses 4 permanent magnets (PM) that pass by 6 u shaped electromagnets (EM) in an outer wheel, creating 12 posts of alternating polarity. The relay needs to turn power on to the EM as the PM passes by and then off as the PM passes by the second pole of the same EM. The speed on the rotor will be variable hence the need to somehow read it's speed and send that information to the arduino to signal the relays correspondingly. I thought a device that emits a laser that reads movement, such as a mouse, would work well for this application. I hope this makes sense.
Looking forward to your response.
Kai

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I thought a device that emits a laser that reads movement, such as a mouse, would work well for this application.

It's not the laser that reads movement. The laser is there simply to provide something for a light sensor to read.

But, since you already have magnets attached to the rotor, a hall-effect sensor seems perfect for you. Polling the sensor may be enough, of the rotor moves slow enough. Otherwise, use an interrupt to register the magnet going by.

The speed on the rotor will be variable

So, anywhere between 1 rpy and 30,000 rps?

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well I certainly hope the speed of the rotor is more than 1 rpy :wink: lol somewhere closer to 20,000 rpm. so with the "hall laser sensor" (not to sure what that is offhand but I will research it) then could the arduino unit switch the relays on and off as I described? thanks again. If you want the schematics I would be happy to send them to you. I am trying to build a free energy device.
cheers Kai