On 06/15/2022 09:42 AM, Joe Gwinn wrote:
>> Somehow I associate those with the Sturmey-Archer
>> three speed hubs.
> A blast from the past. I got very good at adjusting and repairing
> them.
>
> It took me a year to figure out why, when pedaling strongly the foot
> crank would abruptly come loose, free-rotate a half-turn or so, and
> then reconnect, as if nothing had happened.

I was very please when I moved from a balloon tire coaster brake model
to my first 'English' bicycle. I bought it used and abused with my 8th
grade graduation presents. I learned quite a bit about springs, cogs,
pins, and the other internals.

After that experience there was close to a 20 year gap before I bought a
10 speed. Derailleurs have their moments but nothing like a SA.

> I recall similar things from the 1960s as well. Was never tempted. I
> bet they sounded like an infuriated bumblebee, only higher pitched.
> And LOUD.

I was tempted but moved on to a real motorcycle, a '55 panhead. It was
loud but not to be mistaken for a bumblebee.

On 06/15/2022 10:24 AM, Don wrote:
> My own mountain cycling takes place year around. Throughout the winter:
>
> <https://crcomp.net/arts/spintale/winter.png>

Do you run studs?

On 06/15/2022 12:04 PM, Don wrote:
> People sometimes ask me about my bicycle's fat tires. The tires are
> fatter than those found on small motorcycles. They help me navigate
> through light, dry snow. Fat tires are also ideal to yield three feet
> over on the gravelly shoulder of the paved highway through the foothills
> when a big pickup truck with extra wide mirrors screams past. If you
> look closely at the left handlebar of my bike, you can spot a rear-view
> mirror to keep me situationally aware of things going on behind my back.

They must be a joy to pedal. Some I've seen are actually bigger than the
front tire on my DR650 and that has a 650cc thumper to do the pedaling.

Definite yes on the rear view. I have one bike without a mirror and I
keep glancing at the hole where it's supposed to be. I've never come to
terms with those mirrors mounted on your glasses.

On 06/15/2022 11:08 AM, Dimiter_Popoff wrote:
> On 6/15/2022 9:02, Don Y wrote:
>> ......
>>
>> I've been looking for an "alternate" form of transportation for the
>> little jaunts -- to the library, post office, etc. Just a couple of
>> miles, likely off-road.
>>
>> Things like bicycle, Segway, one-wheels, etc. come to mind. But, none
>> have really checked all the boxes (e.g., carrying a bag of groceries
>> on a bike or Segway is really not ideal).
>
> I manage to carry a 5-6 kg backpack biking from the nearby (4-5 km)
> shops. And the way back is uphill (not dramatic though). If it is
> reasonably flat in your area you will just need a backpack similar
> to mine - Lucy gave it to me when I got the bike, she had used it
> years ago when she was walking up the mountains. Very light but
> strong enough.
>
>>
>> But, recently, I'm liking the idea of a small gas powered generator
>> tucked in the battery compartment of my electric wheelchair (!).
>> This would eliminate the maintenance issue of the batteries
>> ($400/set) as well as increase the possible RELIABLE range of
>> the chair. (of course, you couldn't use it indoors but that's fine)
>>
>> Building on that idea, a gas powered Segway? <grin> >
>
> I have seen "normal" bicycles with a battery and some electric
> motor... I was told the motor just helps you, they are made not
> to move on their own, you have to pedal but you get assistance
> (making life easier uphill I suppose). Some nonsense that, why
> would I bike if I didn't want the exercise.

Some do not require any pedaling. Locally they're trying to find a way
to legally differentiate between the two.

On 06/15/2022 11:41 AM, Don Y wrote:
> n 6/15/2022 10:08 AM, Dimiter_Popoff wrote:
>> On 6/15/2022 9:02, Don Y wrote:
>>> ......
>>>
>>> I've been looking for an "alternate" form of transportation for the
>>> little jaunts -- to the library, post office, etc. Just a couple of
>>> miles, likely off-road.
>>>
>>> Things like bicycle, Segway, one-wheels, etc. come to mind. But, none
>>> have really checked all the boxes (e.g., carrying a bag of groceries
>>> on a bike or Segway is really not ideal).
>>
>> I manage to carry a 5-6 kg backpack biking from the nearby (4-5 km)
>
> Yeah, that would work. Often, I'm not carrying anything more than
> something that needs to be mailed (at the post office) or returned
> (to the library). So, getting my body mass from here to there is
> the bigger issue.

I tacoed a wheel while carry groceries in a backpack. Not a good idea,
getting slammed with a few cans of tunafish.

John Dope <always.look@message.header> wrote in
news:t8aiai$34s$1@dont-email.me:

> On Android? Can anybody name one such Android app (with a decent
> rating) that DOESN'T work off-line (at least after you have paid
> the 1 or $2 for it)? There are plenty of hiking apps, obviously
> all of them work off-line.
>

There are a lot of games that do not work offline for obvious
reasons.

Cant play Euchre with a worldwide set of opponents offline.

D'Oh! John Dope is not very bright.

On 6/15/2022 8:43 PM, rbowman wrote:
> On 06/15/2022 09:33 AM, Don Y wrote:
>>
>> Bikes won't work well as I'd want to be able to take the "shortcuts"
>> over dirt/gravel/grass. Something more "ATV-ish" is called for.
>> Hence the Segway option. (The Segway "egg" looks do-able)
>
> https://www.montaguebikes.com/product/paratrooper/
>
> Any mountain bike will be at home off the pavement. I've got a Montague because
> I wanted a full-sized folding bike I can put in the back of the Yaris. Bike
> racks and hatchbacks don't play well together.

Bike relies heavily on rider. My body is no longer as "pliable"
as it used to be, making reaction times a significant issue to
ridership.

>> I also have to be wary of the laws regarding where you can operate
>> said "conveyance". E.g., I don't think bicycles are allowed on sidewalks.
>> And, the rules for ebikes might be different.
>
> I don't think sidewalk riding is illegal here but I wonder about the people who
> ride on sidewalks or the shoulder of the road when there's a perfectly good
> bike path six feet away.

Bike paths, for the most part, run along the washes; a few in town but they
share the pavement with vehicles (which is where bikes are supposed to ride).

Here, cities have final authority over regulating bikes. Tucson prohibits
riding bikes on sidewalks (unless posted otherwise). Other localities can
set their own restrictions/permissions.

> Ebikes are up in the air. They're banned on quite a few trails but there's no
> blanket prohibition. There's an attempt to distinguish between electric assist
> and outright electric drive.

eBikes (of all kinds) and "motorized bikes" are treated like bicycles wrt
sidewalk riding. There are some distinctions (Watts or cc's) that allow for
the bike to be classed as a "scooter"/moped which just makes it harder
to think of it as suitable for sidewalk use.

Wheelchairs are deliberately accommodated on sidewalks with specifications
as to the slope of the on/off ramps, "texture" to alert users that they
are entering/exiting the roadway, etc.

I'm sure electric wheelchairs are classed the same as regular wheelchairs.
There's the possibility that some narrow-minded cop might consider a
gas-generator powered electric wheelchair to be considered a "motor bike"
but I suspect that wouldn't hold up in court (there is nothing that
states HOW the power is sourced)

I suspect Segways would be classed as ebikes, if the statutes were
parsed carefully.

>> Years ago, I tried the bike approach. Driving on the roads is just too
>> perilous. Having to cross 4 lanes of 45+MPH traffic several times on each
>> "short trip" left my nerves jangled.
>
> Forty tears ago I'd ride on Boston streets. Over the years I gotten much more
> paranoid. I gave up a favorite route because it's a narrow two lane road with
> no shoulder. The fog line is the edge of the pavement and there's only a ditch
> past it. Most people are good but it is frequented by F350 dualies pulling
> stock trailers.
>
> The other route is on a very wide shoulder for about three miles and then a
> bike/pedestrian path.

When I was younger, traffic wouldn't bother me. I'd ride from my place in
Medford, down Mystic Valley/Alewife Brook/Fresh Pond -Parkways to pick up
take-out at Big Joyce Chen's -- navigating the delightful 55MPH rotaries
along the way (talk about hair-raising!).

Or, down Mass Ave to school, crossing Harvard Sq "the wrong way" to cut a block
off the trip.

I was more "nimble" on the bike than on foot. Now, the reverse is the case
(I can get my body out of harms way a lot easier than I'd be able to get
it AND a bike out!)

Typical idiotic irrelevant response from Always Wrong...

--
DecadentLinuxUserNumeroUno@decadence.org wrote:

> Path: eternal-september.org!reader02.eternal-september.org!aioe.org!5U2ooNuM5UP0Ynf/GmOnCg.user.46.165.242.91.POSTED!not-for-mail
> From: DecadentLinuxUserNumeroUno@decadence.org
> Newsgroups: sci.electronics.design
> Subject: Re: Spoke sensor for bicycle
> Date: Thu, 16 Jun 2022 04:20:50 -0000 (UTC)
> Organization: Aioe.org NNTP Server
> Message-ID: <t8eb32$1448$1@gioia.aioe.org>
> References: <t8aapr$ab6$1@dont-email.me> <t8afpb$t21$6@dont-email.me> <c5ca6563-7e71-4ec9-b167-5ffb2b3482e6n@googlegroups.com> <t8aiai$34s$1@dont-email.me>
> Injection-Info: gioia.aioe.org; logging-data="37000"; posting-host="5U2ooNuM5UP0Ynf/GmOnCg.user.gioia.aioe.org"; mail-complaints-to="abuse@aioe.org";
> User-Agent: Xnews/5.04.25
> X-Notice: Filtered by postfilter v. 0.9.2
> Xref: reader02.eternal-september.org sci.electronics.design:671764
>
> John Dope <always.look@message.header> wrote in
> news:t8aiai$34s$1@dont-email.me:
>
>> On Android? Can anybody name one such Android app (with a decent
>> rating) that DOESN'T work off-line (at least after you have paid
>> the 1 or $2 for it)? There are plenty of hiking apps, obviously
>> all of them work off-line.
>>
>
> There are a lot of games that do not work offline for obvious
> reasons.
>
> Cant play Euchre with a worldwide set of opponents offline.
>
> D'Oh! John Dope is not very bright.
>
>

In message-id <t6nt3e$7bp$3@dont-email.me>
(http://al.howardknight.net/?ID=165357273000) posted Thu, 26 May 2022
12:50:54 -0000 (UTC) John Dope stated:

> Always Wrong, the utterly foulmouthed group idiot, adding absolutely
> NOTHING but insults to this thread, as usual...

Yet, since Wed, 5 Jan 2022 04:10:38 -0000 (UTC) John Dope's post ratio
to USENET (**) has been 59.3% of its posts contributing "nothing except
insults" to USENET.

** Since Wed, 5 Jan 2022 04:10:38 -0000 (UTC) John Dope has posted at
least 1785 articles to USENET. Of which 173 have been pure insults and
885 have been John Dope "troll format" postings.

The John Dope troll stated the following in message-id
<sdhn7c$pkp$4@dont-email.me>:

> The troll doesn't even know how to format a USENET post...

And the John Dope troll stated the following in message-id
<sg3kr7$qt5$1@dont-email.me>:

> The reason Bozo cannot figure out how to get Google to keep from
> breaking its lines in inappropriate places is because Bozo is
> CLUELESS...

And yet, the clueless John Dope troll has continued to post incorrectly
formatted USENET articles that are devoid of content (latest example on
Thu, 16 Jun 2022 12:51:18 -0000 (UTC) in message-id
<t8f906$n4h$3@dont-email.me>).

NOBODY likes the John Doe troll's contentless spam.

This posting is a public service announcement for any google groups
readers who happen by to point out that Troll Doe does not even follow
the rules it uses to troll other posters.

zT5LYfOE1c7c

rbowman wrote:
> Don wrote:
>> My own mountain cycling takes place year around. Throughout the winter:
>>
>> <https://crcomp.net/arts/spintale/winter.png>
>
> Do you run studs?

No. Winter spins on the storied North Face of the mountain south of town
are more infrequent, shorter, and require more preconditions. Such spins
primarily keep my legs in shape for summer fun. (If you don't use it you
lose it.)
In the Winter the paved road to a promontory called Lookout must be
mostly dry. Although snowy patches here and there are OK and crunchy
rime ice is OK; black ice is a show stopper.
The temperature at the start must be above 39 degrees F. Your own
body heat keeps you toasty under a windbreaker thrown over a long sleeve
t-shirt. Your own sweat drenches you, and becomes a very big problem on
the way down.
Southern chinook winds warm the town in the dead of Winter. But,
they also agonize ascents on the North Face. Imagine gale force
headwinds as you pedal a bicycle up a mountain.
The ideal time for an ascent in Winter is when a storm first starts
to blow in. The chinook eases off to slowly give way to a Northern
tailwind.
Of course the tailwind's cold and it becomes a headwind on the way
back down. Remember my sweat drenched clothes? Add a nominal North wind
of 20 MPH to a nominal 40 MPH downhill speed and you face a 60 MPH wind
chill. Frozen digits on the way down become your biggest problem.

Danke,

--
Don, KB7RPU, https://www.qsl.net/kb7rpu
There was a young lady named Bright Whose speed was far faster than light;
She set out one day In a relative way And returned on the previous night.

John Dope <always.look@message.header> wrote in news:t8f906$n4h$3@dont-
email.me:

>
> Typical idiotic irrelevant response from Always Wrong...
>

The idiot John Dope challenges a response, it gets filled, and then
the putz denies he challenged anyone and declares their response to be
irrelevant, when it addressed the challenge 100%. And uses name
calling like the immature little school boy putz mentality dumbfuck he
is.

You really are an immature old fool, John Dope.

In Today's News...

Michigan Attorney General Dana Nessel said Wednesday that there should be "a
drag queen for every school."

https://www.breitbart.com/politics/2022/06/16/nolte-michigans-attorney-general-wants-drag-queen-every-school/

"Drag queens are entertainment. And you know what I'll say that was totally
not poll-tested, I'd say this - 'A drag queen for every school'""

San Francisco Democrat DA was recalled last week (terminated), now Los
Angeles Democrat DA is being pursued by Terminator Recall.

Apparently the current administration is promoting record gas prices, to
reduce consumption. Of course that will help Democrats get elected...

On 06/16/2022 09:28 AM, Don wrote:
> In the Winter the paved road to a promontory called Lookout must be
> mostly dry. Although snowy patches here and there are OK and crunchy
> rime ice is OK; black ice is a show stopper.

It certainly is. I was riding a trail that was mostly clear and came to
a patch of smooth ice. I figured I could blow past it but physics
disagreed.

On 16/6/22 14:07, rbowman wrote:
> On 06/15/2022 11:08 AM, Dimiter_Popoff wrote:
>> I have seen "normal" bicycles with a battery and some electric
>> motor... I was told the motor just helps you, they are made not
>> to move on their own, you have to pedal but you get assistance
>> (making life easier uphill I suppose). Some nonsense that, why
>> would I bike if I didn't want the exercise.
>
> Some do not require any pedaling. Locally they're trying to find a way
> to legally differentiate between the two.

Those aren't road-legal here in Australia, though some folk have them
anyway.

Road use has three legal requirements:
* 250W max
* no assist above 27km/hr
* no assist unless pedalling (no throttle)

Clifford Hetah.

On 6/17/2022 6:24, rbowman wrote:
> On 06/16/2022 09:28 AM, Don wrote:
>>     In the Winter the paved road to a promontory called Lookout must be
>> mostly dry. Although snowy patches here and there are OK and crunchy
>> rime ice is OK; black ice is a show stopper.
>
> It certainly is.  I was riding a trail that was mostly clear and came to
> a patch of smooth ice. I figured I could blow past it but physics
> disagreed.

To me riding when there is snow is too much of a madness. I do ride
during the winter months when it is dry and I have occasionally landed
on a patch of snow, barely being able to control the slide (it typically
happens at a curve on my daily track where the snow melts slowest).
My tires are perhaps half as wide as Don's, may be 1/3, but still.

On Thursday, June 16, 2022 at 11:24:15 PM UTC-4, rbowman wrote:
> On 06/16/2022 09:28 AM, Don wrote:
> > In the Winter the paved road to a promontory called Lookout must be
> > mostly dry. Although snowy patches here and there are OK and crunchy
> > rime ice is OK; black ice is a show stopper.
> It certainly is. I was riding a trail that was mostly clear and came to
> a patch of smooth ice. I figured I could blow past it but physics
> disagreed.

You need at least one more wheel for that to work.

--

Rick C.

-++ Get 1,000 miles of free Supercharging
-++ Tesla referral code - https://ts.la/richard11209

On 2022-06-14, Ricky <gnuarm.deletethisbit@gmail.com> wrote:
> On Tuesday, June 14, 2022 at 1:16:34 PM UTC-4, John Doe wrote:
>> Dimiter_Popoff <d...@tgi-sci.com> wrote:
>>
>> > I started cycling again (used to as a kid...) some 4 years ago. And
>> > while I know there are plenty of super cheap "bicycle computers" I have
>> > been thinking of making my own. Thus so far 4 years no speed/mileage
>> > indicator for me, obviously. While this may likely remain the case
>> > forever I am still thinking about it - not the obvious things like the
>> > MCU, display etc., just the rotation sensor. They all use a magnet
>> > placed somewhere on one of the wheels and some sensor, I have used a
>> > Hall sensor for pretty precise positioning of the rotor of our TLD
>> > reader etc., but I only still keep on thinking of making the thing
>> > because I imagine it sensing just the spokes, i.e. making some inductive
>> > sensor.
>> >
>> > I know what I will try out etc., I may even get to designing one before
>> > the millennium is over but well, these thoughts seem to be on topic and
>> > I am sure there are people with more experience making inductive sensors
>> > than I have.
>> This might be blasphemy, but...
>>
>> Speed and mileage indication is easily done with a smartphone these days,
>> at least here in America.
>
> People often talk about cell phones as if they had universal
> coverage. That is true for 99.9% of where people spend their time.
> But that 0.1% of the time, like biking in the woods, you are out of
> cell phone range. So any solution needs to not depend on a cell phone
> connection. If you can use the GPS in your phone without a cell
> connection, great! But I haven't found such a program as yet. Maybe
> I just haven't dug deep enough.

Well it's GPS so it's less reliable in tall cities or deep ravines.
but it doesn't need a cell signal.

--
Jasen.

On 2022-06-14, Joe Gwinn <joegwinn@comcast.net> wrote:
> On Tue, 14 Jun 2022 18:51:21 +0300, Dimiter_Popoff <dp@tgi-sci.com>
> wrote:
>
>>I started cycling again (used to as a kid...) some 4 years ago.
>>And while I know there are plenty of super cheap "bicycle computers"
>>I have been thinking of making my own.
>>Thus so far 4 years no speed/mileage indicator for me, obviously.
>>While this may likely remain the case forever I am still thinking
>>about it - not the obvious things like the MCU, display etc., just
>>the rotation sensor. They all use a magnet placed somewhere on one
>>of the wheels and some sensor, I have used a Hall sensor for
>>pretty precise positioning of the rotor of our TLD reader etc.,
>>but I only still keep on thinking of making the thing because I
>>imagine it sensing just the spokes, i.e. making some inductive sensor.
>>
>>I know what I will try out etc., I may even get to designing one before
>>the millennium is over but well, these thoughts seem to be on topic and
>>I am sure there are people with more experience making inductive
>>sensors than I have.
>>
>
> .<https://en.wikipedia.org/wiki/Variable_reluctance_sensor>

That requires a magnetic material, some spokes are almost
non-magnetic stainless steel. (only very weakly paramagnetic)

Your typical ring gear or tone wheel is steel which is paramagnetic
and prodices a stronger signal as it acts as a conduiit for magnetic
fields and thus influences reluctance more.

You could try putting a strong manetic field parrallel to the axle and
trying to sense when spoke passes by the eddy current that will be
induced (perhaps using a figure-8 coil coaxuial with the magnet).
This seems potentially unreliable though as there may be oxide layers
blocking the current

capacitive sensing is another option, done at base-band (DC bias, no
carrier) it shouldn't need mugh power and a FET gate is probably
sensitive enough, but this might not work well in the damp.

--
Jasen.

On 2022-06-14, Dimiter_Popoff <dp@tgi-sci.com> wrote:
> On 6/14/2022 21:21, whit3rd wrote:
>
> Putting the magnet underneath the tire is an idea. Of course I might
> lose it if I have a flat and repair it on the road (you won't believe
> how often I was getting a flat until I got my latest tires, they claim
> to have some Kevlar and I had just one flat in a year or two (can't
> remember if I got them last year or the year before, almost replacement
> due now). But then I have a decent supply of coin magnets, too (say 1mm
> thick/10mm diameter)...

you could attach the magnet using a tube patch.
I have some 5mm magnets that would fit in a Schrader valve cap.

--
Jasen.

On Friday, June 17, 2022 at 10:30:56 PM UTC-4, Jasen Betts wrote:
> On 2022-06-14, Ricky <gnuarm.del...@gmail.com> wrote:
> > On Tuesday, June 14, 2022 at 1:16:34 PM UTC-4, John Doe wrote:
> >> Dimiter_Popoff <d...@tgi-sci.com> wrote:
> >>
> >> > I started cycling again (used to as a kid...) some 4 years ago. And
> >> > while I know there are plenty of super cheap "bicycle computers" I have
> >> > been thinking of making my own. Thus so far 4 years no speed/mileage
> >> > indicator for me, obviously. While this may likely remain the case
> >> > forever I am still thinking about it - not the obvious things like the
> >> > MCU, display etc., just the rotation sensor. They all use a magnet
> >> > placed somewhere on one of the wheels and some sensor, I have used a
> >> > Hall sensor for pretty precise positioning of the rotor of our TLD
> >> > reader etc., but I only still keep on thinking of making the thing
> >> > because I imagine it sensing just the spokes, i.e. making some inductive
> >> > sensor.
> >> >
> >> > I know what I will try out etc., I may even get to designing one before
> >> > the millennium is over but well, these thoughts seem to be on topic and
> >> > I am sure there are people with more experience making inductive sensors
> >> > than I have.
> >> This might be blasphemy, but...
> >>
> >> Speed and mileage indication is easily done with a smartphone these days,
> >> at least here in America.
> >
> > People often talk about cell phones as if they had universal
> > coverage. That is true for 99.9% of where people spend their time.
> > But that 0.1% of the time, like biking in the woods, you are out of
> > cell phone range. So any solution needs to not depend on a cell phone
> > connection. If you can use the GPS in your phone without a cell
> > connection, great! But I haven't found such a program as yet. Maybe
> > I just haven't dug deep enough.
>
> Well it's GPS so it's less reliable in tall cities or deep ravines.
> but it doesn't need a cell signal.

I suppose that's true if you have an app that doesn't require a network connection. The few apps I've tried don't seem to do much without a cell signal.

Then there's the problem of cell phones running for very long in continuous use without being recharged. A friend's phone would only last a few hours when running a GPS app in his car.

--

Rick C.

+-- Get 1,000 miles of free Supercharging
+-- Tesla referral code - https://ts.la/richard11209

On Friday, June 17, 2022 at 7:30:56 PM UTC-7, Jasen Betts wrote:
> On 2022-06-14, Joe Gwinn <joeg...@comcast.net> wrote:
> > On Tue, 14 Jun 2022 18:51:21 +0300, Dimiter_Popoff <d...@tgi-sci.com>
> > wrote:

> >>I am sure there are people with more experience making inductive
> >>sensors than I have.

> > .<https://en.wikipedia.org/wiki/Variable_reluctance_sensor>
>
> That requires a magnetic material, some spokes are almost
> non-magnetic stainless steel. (only very weakly paramagnetic)

So, sense a sprocket tooth instead, or clip a magnet onto a spoke and don't
rely on the spoke material at all. Hardest problem with reluctance is the
low-output-at-slow-speed problem (Wiegand wire being one solution already mentioned).

On 2022-06-18, whit3rd <whit3rd@gmail.com> wrote:
> On Friday, June 17, 2022 at 7:30:56 PM UTC-7, Jasen Betts wrote:
>> On 2022-06-14, Joe Gwinn <joeg...@comcast.net> wrote:
>> > On Tue, 14 Jun 2022 18:51:21 +0300, Dimiter_Popoff <d...@tgi-sci.com>
>> > wrote:
>
>> >>I am sure there are people with more experience making inductive
>> >>sensors than I have.
>
>> > .<https://en.wikipedia.org/wiki/Variable_reluctance_sensor>
>>
>> That requires a magnetic material, some spokes are almost
>> non-magnetic stainless steel. (only very weakly paramagnetic)
>
> So, sense a sprocket tooth instead, or clip a magnet onto a spoke and don't
> rely on the spoke material at all. Hardest problem with reluctance is the
> low-output-at-slow-speed problem (Wiegand wire being one solution already mentioned).

You can mitigate the amplitude problem somewhat by parallelling a
capacitor, but that won't boost the voltage at low speed, it just puts
a hard limit on the high-speed output.

Wiegand needs to be re-magnetised to the opposite polarity to produce a pulse, but two magnets
are probably not a deal breaker if one is acceptable.

--
Jasen.

On 15/06/2022 07:52, Jan Panteltje wrote:
> On a sunny day (Tue, 14 Jun 2022 17:56:50 -0400) it happened Joe Gwinn
> <joegwinn@comcast.net> wrote in <4a0iahhpmhi9ocv7ig0k1nidjn95mqbbg1@4ax.com>:
>
>> Well, there is also Wiegand-wire sensors:
>>
>> .<https://en.wikipedia.org/wiki/Wiegand_effect>
>>
>> .<https://en.wikipedia.org/wiki/Wiegand_Sensor>
>>
>> But as others have noted, the spokes may be non-magnetic. This can be
>> solved by adding a bit of zinc-plated mild steel tubing (automotive
>> brake line) glued to at least one spoke with a silicon rubber
>> adhesive. The spoke would pass through an inch of tube, with silicon
>> rubber filling the gap between tube and spoke.
>>
>> Joe Gwinn
>
> Just thinking, use a camera looking down
> The speed can be derived from the moving pattern it sees
> Almost like a computah mouse...

Forty years or so ago I was doing some work for either Austin Rover or
British Leyland, can't remember which world-leading high-quality British
car manufacturer, there were so many.

Anyway, a test car they used had something like that - an optical device
looking at the road to accurately measure speed. IIRC it was very
expensive.

I have a feeling it was something to do with diffraction gratings and
prisms.

--
Cheers
Clive

Clive Arthur wrote:
> On 15/06/2022 07:52, Jan Panteltje wrote:
>> On a sunny day (Tue, 14 Jun 2022 17:56:50 -0400) it happened Joe Gwinn
>> <joegwinn@comcast.net> wrote in
>> <4a0iahhpmhi9ocv7ig0k1nidjn95mqbbg1@4ax.com>:
>>
>>> Well, there is also Wiegand-wire sensors:
>>>
>>> .<https://en.wikipedia.org/wiki/Wiegand_effect>
>>>
>>> .<https://en.wikipedia.org/wiki/Wiegand_Sensor>
>>>
>>> But as others have noted, the spokes may be non-magnetic.  This can be
>>> solved by adding a bit of zinc-plated mild steel tubing (automotive
>>> brake line) glued to at least one spoke with a silicon rubber
>>> adhesive.  The spoke would pass through an inch of tube, with silicon
>>> rubber filling the gap between tube and spoke.
>>>
>>> Joe Gwinn
>>
>> Just thinking, use a camera looking down
>> The speed can be derived from the moving pattern it sees
>> Almost like a computah mouse...
>
> Forty years or so ago I was doing some work for either Austin Rover or
> British Leyland, can't remember which world-leading high-quality British
> car manufacturer, there were so many.
>
> Anyway, a test car they used had something like that - an optical device
> looking at the road to accurately measure speed.  IIRC it was very
> expensive.
>
> I have a feeling it was something to do with diffraction gratings and
> prisms.
>

There's a fun effect that's sometimes used in sensors for things like
paper handlers: if you shine a laser on a rough surface, the speckle
pattern moves exactly twice as fast as the surface. This turns out to
be a fairly deep consequence of the law of reflection.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

On Tuesday, June 14, 2022 at 11:51:30 AM UTC-4, Dimiter Popoff wrote:
> I started cycling again (used to as a kid...) some 4 years ago.
> And while I know there are plenty of super cheap "bicycle computers"
> I have been thinking of making my own.
> Thus so far 4 years no speed/mileage indicator for me, obviously.
> While this may likely remain the case forever I am still thinking
> about it - not the obvious things like the MCU, display etc., just
> the rotation sensor. They all use a magnet placed somewhere on one
> of the wheels and some sensor, I have used a Hall sensor for
> pretty precise positioning of the rotor of our TLD reader etc.,
> but I only still keep on thinking of making the thing because I
> imagine it sensing just the spokes, i.e. making some inductive sensor.
>
> I know what I will try out etc., I may even get to designing one before
> the millennium is over but well, these thoughts seem to be on topic and
> I am sure there are people with more experience making inductive
> sensors than I have.

You're talking about devices that sell on Aliexpress for $1.29.

If you're a halfway serious cyclist, there are computers that measure cadence, pedal rotations per minute, again with a magnet attached to the pedals, in addition to the usual RPM/ speed and total distance. Looks like the reed relays have been abandoned in favor of hall effect or the giant magntoresistance technology, dunno which. The packages are way too flat to house a relay. The little magnets and their housing look unchanged from the reed relay days.
Plotting the actual route has always been a big deal for road cyclists, so I imagine GPS is used for that in the high end units- but they still need magnets and sensors for cadence measurement, and probably a backup for wheel RPM.

The so-called industrial designers look first at the kind of functionality and form the prospective users will most likely want, and only then hand the design off to nuts and bolts people capable of making a physical product.
You'll be hard pressed to improve upon or innovate existing products.

>
> ======================================================
> Dimiter Popoff, TGI http://www.tgi-sci.com
> ======================================================
> http://www.flickr.com/photos/didi_tgi/