"Phil, Squid-in-Training" <[email hidden]> wrote in message "]news:[email hidden]...
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But, it may go by the sensor so fast the mechanical switch may not have
time
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to fully engage before loosing the magnetic field. Maybe not likely,
but
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possible.
I'm pretty sure the pickup is electric, not mechanical. If you hear
clicky
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noises inside your pickup, then it's either mechanical or broken.
-- Phil, Squid-in-Training
Listen closely. The one on my cateye enduro 2 makes a very very quiet click when the sensor goes by - and yes, I'm pretty sure the magnet and sensor aren't hitting!
If it is mechanical, I'm not 100% sure why - you think they'd just use the electrical field. Might help them avoid interference from HRMs and the like, though...
"di" <[email hidden]> wrote in message news:Cvalb.6611$B_2.6270@okepread02...
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My computer gives very specific directions to mount it near the hub. I may work further up, but there is a difference. The magnet will fly by the pickup a lot faster if it is near the rim.
It will be travelling faster, but it will still go around the same number of times in a given interval. That is all the computer cares
about.
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But, it may go by the sensor so fast the mechanical switch may not have
time
Quoted message said:
to fully engage before loosing the magnetic field. Maybe not likely,
but
Quoted message said:
possible.
Should that happen, fit a stronger magnet. I fit a couple small, round shaped 'rare earth' (neodymium (sp?)) ones out of an old small headphone set - just wrapped a strip of I/tube rubber around them and the spokes, and zip-tied each end or the rolled rubber 'tube'.
To solve any problem like this fitting one, you need to first look at the problem, then apply generous doses of imagination and common sense. It's easy to find the materials.
"Phil, Squid-in-Training" <[email hidden]> wrote in message "]news:[email hidden]...
Quoted message said:
Quoted message said:
But, it may go by the sensor so fast the mechanical switch may not have
time
Quoted message said:
to fully engage before loosing the magnetic field. Maybe not likely,
but
Quoted message said:
possible.
I'm pretty sure the pickup is electric, not mechanical. If you hear
clicky
Quoted message said:
noises inside your pickup, then it's either mechanical or broken.
They are (all I've seen) electro mechanical devices known as 'reed switches' - a glass tube inside which is one (or 2 opposite each other, connected together) static contact 'rod', and a flexible, springy one that is either a magnet itself, or made of a ferric material. I haven't come across one in this application that uses a hall effect or similar.
"Jon Bond" <[email hidden]> wrote in message "]news:[email hidden]...
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If it is mechanical, I'm not 100% sure why - you think they'd just use the electrical field.
Too much physical bulk for signal-out level using a coil, coils are a lot more costly to manufacture, and the signal would be somewhat sinusoidal, hence more difficult to read accurately by a processor without being pre-processed. Hall effect would need a little more in the way of circuitry and cost more also. Reed switches are cheap, reliable, and give a direct on-off output signal of whatever level is desired (feed it 3 volts, that's the return signal level), within the current/voltage parameters the reed switch can handle (which is much more than could be required of it for these jobs).
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Might help them avoid interference from HRMs and the like, though...
"Jon Bond" <[email hidden]> wrote in message "]news:[email hidden]...
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If it is mechanical, I'm not 100% sure why - you think they'd just use the electrical field.
Too much physical bulk for signal-out level using a coil, coils are a lot more costly to manufacture, and the signal would be somewhat sinusoidal, hence more difficult to read accurately by a processor without being pre-processed. Hall effect would need a little more in the way of circuitry and cost more also. Reed switches are cheap, reliable, and give a direct on-off output signal of whatever level is desired (feed it 3 volts, that's the return signal level), within the current/voltage parameters the reed switch can handle (which is much more than could be required of it for these jobs).
I dunno about any of the above kefuffle. But I do know that most cycle computer sensors have a tiny magnet inside that moves when the wheel magnet goes by, thus completing a circuit and sending one unit of information back to the handlebars.
"Anthony Sloan" <[email hidden]> wrote in message "]news:[email hidden]...
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Shaun Rimmer said:
"Jon Bond" <[email hidden]> wrote in message "]news:[email hidden]...
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If it is mechanical, I'm not 100% sure why - you think they'd just use
the
Quoted message said:
Quoted message said:
Quoted message said:
electrical field.
Too much physical bulk for signal-out level using a coil, coils are a
lot
Quoted message said:
Quoted message said:
more costly to manufacture, and the signal would be somewhat sinusoidal, hence more difficult to read accurately by a processor without being pre-processed. Hall effect would need a little more in the way of
circuitry
Quoted message said:
Quoted message said:
and cost more also. Reed switches are cheap, reliable, and give a direct on-off output signal of whatever level is desired (feed it 3 volts,
that's
Quoted message said:
Quoted message said:
the return signal level), within the current/voltage parameters the reed switch can handle (which is much more than could be required of it for
these
Quoted message said:
Quoted message said:
jobs).
I dunno about any of the above kefuffle. But I do know that most cycle computer sensors have a tiny magnet inside that moves when the wheel magnet goes by, thus completing a circuit and sending one unit of information back to the handlebars.
Sysiphean torture, sounds like.
That "kefuffle" made perfect sense to me. A reed switch is a "tiny magnet" or magnetic strip of metal encased in a glass tube. We use them for position sensors. You can also find them in security systems as window and door open/close sensors.
"Anthony Sloan" <[email hidden]> wrote in message "]news:[email hidden]...
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Shaun Rimmer said:
"Jon Bond" <[email hidden]> wrote in message "]news:[email hidden]...
Quoted message said:
If it is mechanical, I'm not 100% sure why - you think they'd just use
the
Quoted message said:
Quoted message said:
Quoted message said:
electrical field.
Too much physical bulk for signal-out level using a coil, coils are a
lot
Quoted message said:
Quoted message said:
more costly to manufacture, and the signal would be somewhat sinusoidal, hence more difficult to read accurately by a processor without being pre-processed. Hall effect would need a little more in the way of
circuitry
Quoted message said:
Quoted message said:
and cost more also. Reed switches are cheap, reliable, and give a direct on-off output signal of whatever level is desired (feed it 3 volts,
that's
Quoted message said:
Quoted message said:
the return signal level), within the current/voltage parameters the reed switch can handle (which is much more than could be required of it for
these
Quoted message said:
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jobs).
I dunno about any of the above kefuffle.
It ain't 'kefuffle', it's correct - thos sorta thing is part of my job.
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But I do know that most cycle computer sensors have a tiny magnet inside that moves when the wheel magnet goes by,
Magnetic reed switch - some have magnets and one contact (only work with magnet facing one way), some have magnets and two contacts (work with magnet either way around), yet others just ferrous metal (work with magnet either way around)
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thus completing a circuit and sending one unit of information back to the handlebars.
It ain't 'kefuffle', it's correct - thos sorta thing is part of my job.
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Shaun aRe
C'mon, admit it. You were waggling around your knowledge in order to show off.
;*)
I knew what you were getting at but, and I mean this kindly, it was a trifle obtuse. Best thing to do for the uninformed public (me) is to describe the thing in plain english, then drop in the lingo. If it's a tiny magnet, that's a good enough description for a usenet group concerning itself with mountain biking.
"Anthony Sloan" <[email hidden]> wrote in message "]news:[email hidden]...
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Shaun Rimmer said:
It ain't 'kefuffle', it's correct - thos sorta thing is part of my job.
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Shaun aRe
C'mon, admit it. You were waggling around your knowledge in order to show off.
;*)
AND to be helpful (killin' 2 birds with 1 stone, heheheheheh....).
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I knew what you were getting at but, and I mean this kindly, it was a trifle obtuse. Best thing to do for the uninformed public (me) is to describe the thing in plain english, then drop in the lingo. If it's a tiny magnet, that's a good enough description for a usenet group concerning itself with mountain biking.
Yeah, you'd think, but, 'bollox'! Someone woulda jumped up and said 'You don't know what you're on about you clueless idiot', before commencing to fill in the details where I'd left them out. I was just being pro-active (does that make 3 birds/ 1stone? Heheheheh......).
Yeah, you'd think, but, 'bollox'! Someone woulda jumped up and said 'You don't know what you're on about you clueless idiot', before commencing to fill in the details where I'd left them out. I was just being pro-active (does that make 3 birds/ 1stone? Heheheheh......).
Shaun aRe
I hear you there. 'Tis the double edged sword of Usenet, it is.
Shame about all them birds, good for the stones though.
