Where to start? Dynonameter Build!

Hi everyone!

I just received my Arduino USB Board and am very excited to start my side project. The build is an RC dynonameter and my part is to have sensor that can measure the horsepower at the flywheel with a sensor. I did a little research and came upon a halloeffect sensor? or would a digital sensor such as a schimdt trigger be more ideal?

Any suggestions of where to start? I'd appreciate any help! Thanks!

A Hall Effects sensor could do the job, or some form of optical pickup and a marking on the flywheel.

A schmidt trigger is a totally unrelated concept that has nothing to do with what you seem to be working on. It's a type of digital input circuit that adds some hysteresis. Basically it puts the "on" threshold higher and the "off" threshold lower so that there's no sharp line where the input can become unpredicitable.

To measure the horsepower you will need the motor to drive a load such as a generator(dynamo). By varying the loading on the generator (with lamps, resistors etc) you can measure the generator output amps/volts at different rpm to calculate (roughly) the horsepower.

This just needs a couple of analog inputs and a bit of external circuitry to provide voltage levels suitable for the Arduino.

An optical or hall sensor can be used to measure the flywheel rpm using a digital input.

Incidentally, there does not seem to be anywhere on the forum where this type of question fits properly.

Do odd questions normally go into a FAQ section?

Ok, so i've been searching around. What do you guys think is the best hall effect sensor for my type of project? I have a dynonameter with me but I need a sensor strong enough to put it near the flywheel and have it pick up something. Any suggestions on the hall effect sensor?

A quick check with my local electronics supplier (RS Components UK) showed a multitude of hall sensors all suitable for 5 volt operation.
You need to make sure the flywheel is suitable for this type of sensor because if it is just a round flat disk it will probably not trigger the sensor.