[time-nuts] OT - DC-10 gyros

[DaveH]

Just an idea -- if 440 Hz would work, there are a lot of electronic tuning
fork circuits out there.

Here is one:

http://www.spaennare.se/tfork.html

You could choose another crystal frequency or divide-by ratio if it needs to
be 400.00

Add a phase-shift circuit to get the other two phases (if needed),
amplifiers and you are good to go. 

Dave

> -----Original Message-----
> From: time-nuts-bounces at febo.com 
> [mailto:time-nuts-bounces at febo.com] On Behalf Of bg at lysator.liu.se
> Sent: Thursday, March 28, 2013 05:48
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] OT - DC-10 gyros
> 
> Hi Bill,
> 
> > Well, I can come up with something topical, read on. :)
> 
> [snip]
> 
> > Topical in a more abstract way, strapdown systems really are very
> > interesting. They require precise integration of the rate 
> output over
> > time to derive velocity and position, and really weren't 
> practical until
> > the 70's when small enough computers existed to do the requisite
> > calculations.  (I worked on the nav system for the Trident 
> missile back
> > in my Draper Labs days).
> 
> Well, for the analysis of your gyro performance, time-nuts are already
> equiped with one of the tools used - the Allan Variance.
> 
>     http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=4404126&tag=1
> 
> There is also the relation
> 
>       GPS & oscillator -> GPSDO
> 
> where in the navigation field
> 
>       GPS & 3x gyro + 3x accel   ->  GPS stabilised inertial 
> navigation
> system
> 
> 
> --
> 
>      Björn
> 
> 
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