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Traffic light sensors

K

Ken C

Jan 1, 1970
0
I want to attach neodymium magnets to my bicycle kickstand so my
presence will be sensed by the underground sensors that control some
traffic lights.

I intend to use a few ring magnets, held in place near the bottom of
the kickstand with cable ties. These are plate magnets with the poles
at the flat surfaces.

What is the best way to orient the magnets?

It would be nice if they could work most of the time with the stand
up. If I encounter a difficult sensor, I would swing the kickstand
down to bring the magnets closer to the sensor.

Ken C
 
R

Rich Webb

Jan 1, 1970
0
I want to attach neodymium magnets to my bicycle kickstand so my
presence will be sensed by the underground sensors that control some
traffic lights.

I intend to use a few ring magnets, held in place near the bottom of
the kickstand with cable ties. These are plate magnets with the poles
at the flat surfaces.

What is the best way to orient the magnets?

It would be nice if they could work most of the time with the stand
up. If I encounter a difficult sensor, I would swing the kickstand
down to bring the magnets closer to the sensor.

Except, they don't work that way. See this link for a good discussion
http://www.humantransport.org/bicycledriving/library/signals/detection.htm

The only advantage of the magnets would be that they might induce you
(yuck yuck) to position the bike over the sensitive area of the loop
detector.
 
A

Alan B

Jan 1, 1970
0
I want to attach neodymium magnets to my bicycle kickstand so my
presence will be sensed by the underground sensors that control some
traffic lights.

Don't waste your time. Rather, put the kickstand down on the pavement at
the point where you notice the loop buried. That just might do the trick.
Or, start wearing stainless steel shoes and put your foot down on the loop.
 
R

Rich Grise

Jan 1, 1970
0
Don't waste your time. Rather, put the kickstand down on the pavement at
the point where you notice the loop buried. That just might do the trick.
Or, start wearing stainless steel shoes and put your foot down on the loop.

Lay the bike down, such that the loop of the frame couples to the loop of
the sensor, like the secondary of an air-core transformer. It'll be lossy,
so should trigger the unit. (like one shorted turn, with a very low Q.)
Once, someone posted some links with diagrams of riders doing this, but a
quick search: http://www.google.com/search?q=bicycle traffic sensor
just turns up a lot of verbiage.

Good Luck!
Rich
 
Rich said:
Lay the bike down, such that the loop of the frame couples to the loop of
the sensor, like the secondary of an air-core transformer. It'll be lossy,
so should trigger the unit. (like one shorted turn, with a very low Q.)
Once, someone posted some links with diagrams of riders doing this, but a
quick search: http://www.google.com/search?q=bicycle traffic sensor
just turns up a lot of verbiage.

You don't need a magnet, just something electrically conductive in the
field. I found the best method is to find the crack with the sensor line,
and center one or both of my bike tires right over it. The lower part of
the rims will be close enough to trigger some signals. Some threshholds
are just too high, only a car can trigger them. Even aluminum rims will
do, but forget about fancy carbon rims.

Mike Ross




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E

Electromotive Guru

Jan 1, 1970
0
Erm...did you ever try just riding over to the pedestrian signa
button and pushing it

If this is too techincal for you, take a loop of 22 awg wire about
feet long and wind it into a coil about 1 inch in diameter and imbe
it under the insole of your shoe at about the ball of you
foot...wave your foot over the sensor loop and the light wil
trip...eventually, depending on the DOT-programmed delay which in m
experience in washington state can be anywhere from instant to 2
minutes...

If this doesn't work, consult your local DOT fo
faulty/poorly-controlled traffic signals or just run the light usin
your grey matter over the influence of a simple traffic light and g
when it's clear...If it's a main thoroughfare that you are crossing
just ride up to the pedestrian signal instead of standing in th
middle of the street for hours like an idiot..

There is no techie solution for government stupidity (especially th
DOT), you just have to do it the lemming way anyway....If that stil
doesn't work, think for yourself and go when it's safe..
 
J

Jasen Betts

Jan 1, 1970
0
Don't waste your time. Rather, put the kickstand down on the pavement at
the point where you notice the loop buried. That just might do the trick.
Or, start wearing stainless steel shoes and put your foot down on the loop.

I've had sucess just by putting the wheel on the cut line in the pavement

Bye.
Jasen
 
J

Jasen Betts

Jan 1, 1970
0
You don't need a magnet, just something electrically conductive in the

I've seen one sensor that was spoofed by a ring of metal packing strap
the road was near capacity normally, and with this causing too-frequent
intewrruptions it has traffic held up for 20 minutes....
I found the best method is to find the crack with the sensor line,
and center one or both of my bike tires right over it. The lower part of
the rims will be close enough to trigger some signals.

I think the whole of the rim (and possibly the frame too) couples with with
the field in the loop.
Some threshholds are just too high, only a car can trigger them.
Even aluminum rims will do, but forget about fancy carbon rims.

i wonder if they could be enhanced with by running a copper wire round e the
inside bringing the ends out through the valve hole and joining them there.
 
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