Motor as a rotational sensor?

Thread Starter

julijonas

Joined Jun 15, 2006
1
Hello,

I would like to ask you how to make a small motor as a rotational speed sensor for microcontroller, i.e. I want to pick up the output from the motor as from a small generator. I need to amplify voltage the motor produces (it produces from 0 to 0,7V) to match microcontroller's readings (from 0 to 5V). Shall I use common-collector or base amplifier? How to protect a microcontroller from damage?

Thank you!

Julijonas
 

beenthere

Joined Apr 20, 2004
15,819
Hi,

Try looking up shaft encoders. They give outputs compatible with microcontroller inputs, and require very little elaboration to put in your system.

The ultimate in simplicity is to arrange a small magnet to spin with the shaft, and use a hall-effect sensor to signal when the magnet passes. There is an indication of each shaft rotation, and the output is directly useable by the mc.
 

mrmeval

Joined Jun 30, 2006
833
http://www.sensorwiki.org/index.php/Basic_sensor_interfacing_techniques

julijonas said:
Hello,

I would like to ask you how to make a small motor as a rotational speed sensor for microcontroller, i.e. I want to pick up the output from the motor as from a small generator. I need to amplify voltage the motor produces (it produces from 0 to 0,7V) to match microcontroller's readings (from 0 to 5V). Shall I use common-collector or base amplifier? How to protect a microcontroller from damage?

Thank you!

Julijonas
 
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