Safe Speed Forums

It's perfect for translating mechanical position or rotation into a binary code. Some things never change!

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I stole this .sig

<grin> Same here. I think we can be pretty confident that it's still the best solution for optical digital encoding of shaft rotational position.

No, wait a minute, I'm wrong. I had a remote electronic weathercock and anemometer that was storm damaged about 5 years ago. That had Gray code on the weathercock.

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Paul Smith
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Thanks for the speedo info. That might explain something I once saw on a TR6. The speedo needle waved around rather than pointed to a number, bouncing back and forth between, say, 25 and 40. The guy who owned said something about magnets (can't remember what, I was about 14 at the time). Sound about right to you?Sorry about the wind-up. Just couldn't resist it.

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Make everything as simple as possible, but not simpler - Einstein

I've seen this too, a very long time back. It sounds like a mechanical fault, wear, friction or a kink in the cable that intermittently winds the cable up then unwinds in one go, or some other knackered thing like something waggling about or a bad bearing or teeth missing on a gear etc. etc.

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I stole this .sig

Giving your age away, eh?

Gray code is extensively used for rotational position encoding.
As only one bit changes at a time, it's immune from bit skew errors, and the system can be made insensitive to positional jitter and induced noise as well.

Regards
Peter

Or a badly ftted/loose needle? Had an od A40 that behaved like that- found needle worked loose every so often.
What i'd like to see on motorways is a minimum (for the conditions, obviosly) speed limit - might get rid of old f**t in ancient auto in lane 1

But they are still only guidelines, and how a police officer deals with any given situation is still down to him (or her).

I remember one particular day (many years ago now) being stopped in Grosvenor Square, W1 by Trafpol while I was despatching and the conversation went like this:



Copper: Good morning sir, do you know why I have stopped you?

Me: (thinking) I've got a pretty good idea, where do you want me to start?
Me: (speaking) No mate

Copper: The reason I have stopped you is because we were no more than 10ft behind you and we found it impossible to read your number plate. Now if we couldn't see that while sitting in a Range Rover then what hope does a camera have?

Me: (thinking) That's the general idea matey
Me: (speaking) The reason I have had to bend my number plate at such an angle is to avoid it catching in the rear tyre officer. If I lower it any more than what it already is then all it takes is one pothole and the number plate gets ripped off.

Copper: Hmmm, indeed sir.
Tell me sir, does this vehicle actually have a current MOT?

Me: Yes

Copper: Really?? And how many times did you have to sleep with the tester?

Me: (laughing) Very good mate, but I can assure you the vehicle is roadworthy, take a look for yourself.

Copper: Well I can already see that you have at least one blown fork seal, and as for that exhaust, can you explain why it has "Not for road use" stamped on the end of the silencer (and I use that term loosely) can?

Me: (look of astonishment) Does it really, where?

Copper: I'll tell you what I'll do for you mate, I'm going to let you go on this occasion because I can see that you are actually making an effort to keep it road legal by the new tyres that have just been fitted and I know you despatchers don't earn hundreds of pounds every week.
However, the next time I see you, I want to see that blown fork seal fixed, I want to see a road legal exhaust, and I want to see that number plate sorted....If you haven't got those faults corrected by the next time I see you, then you are nicked....is that clear?

Me: No problem mate, I'll get them all sorted over the next week.



Now a simple "flea in the ear" had it's desired result.
The vehicle itself didn't really present a danger to anybody (even though it did look a bit ropey) and I did fix the faults that he noted....but if the officer involved hadn't used his "savvy", then I could quite easily have been looking at 9 points on my license which would only have served to piss me off, and he would have had so much paperwork to deal with that he would have effectively have been off the road for the rest of the day (which would have meant that he wouldn't have been out there nicking someone who actually deserved it).

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What makes you think I'm drunk officer, have I got a fat bird with me?