Hi John.

11-Aug-03 21:21:10, John Tserkezis wrote to All

 >> No they won't John.  If they did, their cars would not comply with
 >> ADR's,
 JT> whic
 >> actually state that the speed indicator is allowed to display a
 >> speed 10%
 JT> highe
 >> than you are actually travelling, but it does not make any
 >> reference to
 JT> showin
 >> any speed higher than you are actually travelling.

 JT> ^^^^^^ You mean lower?  I've seen this to be the case, but I think
 JT> it was only on modified vehicles (either wheels, diff ratios or
 JT> both).

my car tyres of slightly different rolling radius on the pressure chart
I never really thought much about how it effects the speedo reading.
I haven't tried to test the speedo...

(aside to Andrew)
Do they still have that speedo test between Geeolong and Melbourne?
I haven't seen anything similar in Queensland.
Not that I'm going the drive all the way to Vic to test my speedo!

 JT> why they bother with a speedo in the first place.  I haven't had
 JT> the opportunity to test a digital readout speedo yet.

I guess the acuracy there depends on how it's built.. I could design one
around a digital voltmeter module and a 555 based frequencty to voltage
converter it'd be useless unless properly stabilised for tempertature...

I think most digital speeedos use a sort of frequency counter approach with
a crystal timebase and so should be pretty accurate.

 JT> Unrelated, (but I thought I should mention it because everyone
 JT> makes fun of me when I bring my nav system with me on trips), is
 JT> that we think there was a pileup or something just before
 JT> canberra.  Stuck in traffic standing still for ages.  Someone else
 JT> happened to be on the same channel as us, said he was about 3Km
 JT> ahead of us, and there was a parking lot as far as he could see.

 JT> You can't get lost with GPS.  I used to say you *could* get lost if
 JT> you tried really really hard, but in the few years that I've had it,
 JT> we've tried- hard.

even a compass helps; unless you're in mountainous terrain you can usually
make progress on unfamiliar roads just by pointing your car in the
apropriate direction, if the sun's out you don't even need a compass... (I
tend to get lost at night or on overcast days)

 -=> Bye <=-

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