What's the best way to convert a shaft RPM to a voltage?

Question

I'm looking to convert 0-6000 RPM shaft to 0-10 Volt output proportional to speed e.g. 1 V/ 1000 RPM.. I would use an encoder, but my sample rate is only 100 Hz, so most encoders pulse too quickly to measure.

Answer 1

Not much point in using an encoder. You are only interested in complete revolutions, not the angle.

How about gluing a magnet on to the shaft using araldite? Then use a pickup coil, pass the output through a conditioning circuit (a comparator and an integrator would do).

Answer 2

You could use an analog tachometer.

Answer 3

accumulate the encoder pulse into a counter then strobe the output of the counter. the difference between successive strobes will give you the amount of rotation.

use a digital to analog converter to convert this difference into a voltage.

how many pulses per revolution is your encoder?

Answer 4

Purchase a DC servo.

Answer 5

a tacho generator should serve purpose

unless you have other considerations

example below,

http://www.baumerhuebner.com/analog-tach...

Answer 6

I would not use encoder if your output should be analog.

Use F to V converter circuitry, there are plenty of schematich on the web.

e.g http://www.national.com/mpf/LM/LM2917.ht...