Accurate measurement of rotation
Captain Blammo
Posts: 3
I'm putting together a project that needs to precisely measure (say to within 0.33 degrees) rotation of a tripod head in 2 axes. I've had a poke around this site and the web trying to find an approriate sensor, but haven't turned anything up yet. I'm going to assume that pots may be a bit too shaky for precise use, although I suppose it depends on who makes them.
Any recommendations for something appropriate would be greatly appreciated.
Any recommendations for something appropriate would be greatly appreciated.
Comments
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Jon Williams
Applications Engineer, Parallax
Be aware that a 128 or 256 count encoder will have to be turned slowly or you will lose counts,
I was only able to get about 100 counts per second with a quadrature encoder and a BS2.
If you need to count faster than that, you'll have to add some hardware to do the counting for you.
I think there's something in the Stampworks manual, but if you can't find it,
here's a site that will get you started with that.
abrobotics.tripod.com/Ebot/hardware.htm
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Jon Williams
Applications Engineer, Parallax
Bean.
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It's more hardware than you might've wanted....we use them on our radars
Here's some info on them:
http://www.evaluationengineering.com/pctest/articles/0399daq.htm
http://www.pentlandsys.com/download/synchro/ch1_2.pdf
http://www.pentlandsys.com/download/synchro/ch3.pdf
http://www.pentlandsys.com/download/synchro/ch4.pdf
Analog devices sells some converter IC's in 12, 14 and 16bit flavours.
http://www.analog.com/en/prod/0,,760_791_AD2S83%2C00.html
These are all a bit pricey...but I'm sure you can find some lower end ones that might work for you.
For instance, you could get the hold of an old synchro setup (we used to use them in our old wind equipment) and you could easily attach a 10-turn pot to the end of one of the rotor shafts and just do an RCtime input to your stamp.
Here's a quick look on ebay for ' synchro resolver '
http://cgi.ebay.com/Evershead-Vignoles-Synchro-Resolver-Type-FC34-0_W0QQitemZ7594260290QQcategoryZ42899QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
That address probably won't work unless you copy/paste.
http://cgi.ebay.com/Bendix-HSI-SYNCHRO-Synchronous-Resolver-Receiver-8Pcs_W0QQitemZ7593733146QQcategoryZ71395QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
wrt ebay...buyer beware!
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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."
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Chris Savage
Parallax Tech Support
csavage@parallax.com