Newsgroups: comp.robotics
Path: brunix!news.Brown.EDU!agate!howland.reston.ans.net!europa.eng.gtefsd.com!news.msfc.nasa.gov!sol.ctr.columbia.edu!hamblin.math.byu.edu!wicat!rwas
From: rwas@wicat.com (Robert Wasiersky)
Subject: Re: Cheap gyros 
Message-ID: <1994Feb4.000552.14649@wicat.com>
Organization: WICAT Systems
References: <9401161437.AA23227@algol.demon.co.uk> <758833366snz@cryton.demon.co.uk> <CKKFs9.ADF.3@cs.cmu.edu>
Date: Fri, 4 Feb 1994 00:05:52 GMT
Lines: 51

hbb@e4.ius.cs.cmu.edu (Ben Brown) writes:

>In article <758833366snz@cryton.demon.co.uk>, pcats@cryton.demon.co.uk (Patrick Arnold) writes:
>|> In article <9401161437.AA23227@algol.demon.co.uk> bruce@algol.demon.co.uk writes:
>|> 
>|> >I read in this newsgroup a few weeks ago about there being gyros
>|> >available for under $200. More recently I was browsing through some
>|> >magazines belonging to an aeromodelling enthusiast. It seems that
>|> >there are gyros available for model aircraft for around 60 UKP (that's
>|> ><$100). If anyone reading this knows about these devices I'd be
>|> >interested to hear:
>|> >
>|> >1. How they work, e.g. whether they're inertial or magnetic.
>|> >
>|> >2. Whether they drift.
>|> >
>|> >3. What sort of outputs they produce. I'd guess that they output a
>|> >couple of PWM signals suitable for feeding straight to servos.
>|> >
>|> >4. Anything else about them that would be of interest to someone
>|> >building mobile robots on the cheap!

>Gyration Inc. (Saratoga CA 408-255-3016) sells small vertical and directional
>gyros for ~$500. These are standard gimballed gyros, but the drift specs
>probaly aren't as good as aircraft-quality gyros.

>	Ben


	You might consider tuning fork rate gyro's, proportional voltage
	for a given rate of change in angle. They are supposed to be
	pretty acurate, I have no practical experience with them though.

	BEI GyroChip 1 800 227 1625 last time I checked these thing's where
	about $1k but I'll bet they've come down or gone out of buisness.

	Murata Erie, I can't find my lit's on these guy's, the're unit's
	go for about $200 and are targetted for the auto industry.

	These widget's are small, the GyroChip is 2.25", 1.92, .91,
	It requires +- 5V, and provide's full scale output of +- 2.5V@
	rate's of +-10deg - +-1000deg/sec depending on the flavor you get.
 
	The unit from Murata Erie is not quite as good as the GC.

	The're are some surplus places that have surplus gyro's of all
	Ilk's. I picked up a mechanicel version of a rate gyro for ~$15.
	Non trivial interface though.

	If you would like more info let me know, and I'll try to dig it up.

