Motor as a rotational sensor?
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). Should·I need to amplify voltage the motor produces (it produces from 0 to 0,7V)?·Shall I use RCTIME?·How here to protect a microcontroller from damage?
Thank you!
·
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). Should·I need to amplify voltage the motor produces (it produces from 0 to 0,7V)?·Shall I use RCTIME?·How here to protect a microcontroller from damage?
Thank you!
·
Comments
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
·
Thnks
You need a bridge of diodes because the current produces by a generator is AC and then RC time is a good solution...
I have something in mind that might help (A doc about RCtime circuits but I don't remember the exact URL)...
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
-Rule your Destiny-
--Be Good. Be Bad. Be Provas--
AC/DC motor?
Personally, I'd try to optically isolate the motor windings from my stamp....get creative and use a lightbulb on the motor (rated properly of course) and put it in a box with a photocell. Use RCTime with the photocell to see how its resistance changes with the light levels from the motor speed.
an A/D works too.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
·
Steve
"Inside each and every one of us is our one, true authentic swing. Something we was born with. Something that's ours and ours alone. Something that can't be learned... something that's got to be remembered."
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Chris Savage
Parallax Tech Support
csavage@parallax.com
Look for 1KC317... should do the trick for ya...
Provas, Greece
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
-Rule your Destiny-
--Be Good. Be Bad. Be Provas--
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
·
Steve
"Inside each and every one of us is our one, true authentic swing. Something we was born with. Something that's ours and ours alone. Something that can't be learned... something that's got to be remembered."
Could I solve this without additional IC's, e.g. using RC circuit with common-base amplifier? Does optocoupler transfer variable voltage or binary (i.e. is it analog or digital)?
thnks
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Chris Savage
Parallax Tech Support
csavage@parallax.com
4N25,· AN-3001,· PC2SD11NTZ······ ·
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
-Rule your Destiny-
--Be Good. Be Bad. Be Provas--
·
If you don't go through all this trouble, you won't know how many pulses per revolution to compensate for in your code, and you'll frustrate yourself with false readings.
Although, if you like simple, you can scratch up a few bucks and spring for a hall effect sensor, more acurate, more stable in opperation, no (resistor capacitance), or voltage spike/regulation issues associated with "conditioning" a pulse that becomes increasingly difficult with increased armeture velocity through a magnetic field coupled with "brush noise" (false pulses from carbon buildup on the armature).
I'm sure the last bit was completely overkill but I figured i would throw 2 cents in, i thought it might be helpful for future troubleshooting. Me personally, I'd just go get a hall effect sensor from the parallax store, they even include code examples (which would be smaller and faster than the coding you'd need to compensate for multiple pulses per revolution).
You could utilize a hall effect sensor and maybe a real time clock module to get truely acurate readings, maybe with less coding too.