Post by thread:Tilt Sensors

At 12:42 AM 7/31/97 -0500, you wrote: >Hi all, >This is just a quick question. Does anyone have any experience with tilt >sensors. The ones that I am thinking of will produce a + and - signal for >both an X and a Y tilt. The cost of the one that I have checked on so far is >about $150 US. >Any experiences either good or bad? > >Thanks, >Troy Powledge >TCo. Systems > from an earlier exchange of messages ... "Some years ago I used tiltsensors in a project to monitor feeding behaviour of herbivores (deer). The sensor was mounted in a collar-based transmitter, sending a code for the animal in combination with a tiltcode. The system was used succesfully in the central part of the Netherlands for quite a while. The sensor was of the type SP5000 by SPECTRON Glass & Electronics. It's a "vertical sensing electrolytic potentiometer" with 5 internal electrodes. It measures about 25x13millimeter. Get in touch with Spectron, 595 Old Willets Path, Hauppauge, N.Y.11788 tel. (516)5825600 fax.(516)5825671 Good luck! Willem van der Veer Institute for Forestry and Nature Research P.box 23, 6700-AA Wageningen, The Netherlands. e-mail : spam_OUTw.vanderveerTakeThisOuTibn.dlo.nl " Regards, Ross McKenzie Melbourne Australia

Visit http://www.rcboats.com The owner is a customer of mine. Send him mail and ask about buying his sensor. The sensor module itself goes for $25-$30 AFAIK. Andy At 12:42 AM 7/31/97 -0500, you wrote: {Quote hidden}>Hi all, >This is just a quick question. Does anyone have any experience with tilt >sensors. The ones that I am thinking of will produce a + and - signal for >both an X and a Y tilt. The cost of the one that I have checked on so far is >about $150 US. >Any experiences either good or bad? > >Thanks, >Troy Powledge >TCo. Systems > > ================================================================== Andy Kunz - Montana Design - 409 S 6th St - Phillipsburg, NJ 08865 Hardware & Software for Industry & R/C Hobbies "Go fast, turn right, and keep the wet side down!" ==================================================================

> From: Troy Powledge <.....tpowKILLspam@spam@ERAMP.NET> > This is just a quick question. Does anyone have any experience with tilt > sensors. The ones that I am thinking of will produce a + and - signal for > both an X and a Y tilt. The cost of the one that I have checked on so far is > about $150 US. > Any experiences either good or bad? No experience but Philips do a magnetoresistive sensor which they claim is superior in several respects to the normal hall effect designs. No doubt your friendly Philips' Sales Office would be happy to help. :-)

You should contact the Fredericks Company, or Spectron Glass and Electronics. Both of these make electolytic vial-based tilt sensors, with resolutions that can be below a tenth of a percent of slope. These devices consist of a curved glass tube, with an electrode at each end, and a center electrode. A bubble in the electrolyte moves back and forth based on slope (the traditional bubble level, electrified) and the center electrode is used to measure the bubble position. There are some constraints; these devices will fail if exposed to DC currents (that means even an ohmmeter!) so they must be completely capacitor- coupled. The usual method is to drive the ends from a differential output amplifier, then use a precision bridge to rectify the center electrode signal, amplify the resulting DC and meaure the amplitude to derive slope. Note that a conventional diode bridge won't work; too much deadband in the middle. Non-linearities can occur because of the drive electronics, or because the glass vial isn't *exactly* a uniform curve. In the application I used these on, we bought vials to a specified degree of precision. We could get others for less money, but they weren't as precise. Nowadays, I'd buy the cheap ones and linearize them with a table in ROM....but back then, that was still a bit exotic. Precision slope measurement is a surprisingly tricky problem, and the choice of sensing technology is really dependent on what precision you need and what the intended environment is. Mark G. Forbes, R & D Engineer | Acres Gaming, Inc. (541) 766-2515 KC7LZD | 815 NW 9th Street (541) 753-7524 fax forbesmKILLspampeak.org | Corvallis, OR 97330 http://www.peak.org/~forbesm .....mforbesKILLspam.....acresgaming.com "There has been an alarming increase in the number of things I know nothing about." ---Anomalous