Topic: green light trigger

[burmashave]

Hey Moto-bunny, our MSF instructor told us to look for bicycle lane sensors. They're marked here in upstate NY with a painted bike symbol. They look like the cuts/wires for the normal ones; but the triggering for the bike sensors is supposed to be much, much more sensitive than those for cars. Mebbe you've already tried this, but if you haven't, I would guess there are lots of bike lanes/sensors in Portland.

Since I was imparted with that tidbit, I've started rolling up to the bicycle sensor even when I'm in my car. And while we're talking sensors, has anyone else noticed that some intersections now have multiple full sets of sensors, one in front of the other, for a given lane? My guess is that there is some sensor anti-logic that switches the light faster if more than one car is detected. Thus, I make sure my car is over both when I see one a set. ;-)

[Joel]

I teach electrical apprentices here in Oregon. Many of our electricians are hired to install these sensors, I've even install one myself. Knowing how they work, I thought I'd buy on of those triggering devices (a different brand than the original post). It's just a strong magnet, which would work if it could somehow be isolated from the rest of the bike. Since it's attached to the bike (separated by a plastic case) it adds it's magnetic field to the bikes field. This is a bit like peeing in the ocean to try and change the tides. I did notice an improvement on a couple of signals around Portland, but I still found a couple that wouldn't trip.

Maybe a strong horse shoe magnet built into the heal of your riding boot??

I like this idea.  The magnets in the video look small enough to fit.  You might pick up a lot of scrap metal on your sole though.   If I have trouble with the sensor lights, I may give the shoe magnet a try.

[MoTo-BunnY]

Hey Moto-bunny, our MSF instructor told us to look for bicycle lane sensors. They're marked here in upstate NY with a painted bike symbol. They look like the cuts/wires for the normal ones; but the triggering for the bike sensors is supposed to be much, much more sensitive than those for cars. Mebbe you've already tried this, but if you haven't, I would guess there are lots of bike lanes/sensors in Portland.

That's good to know - thanks for the tip! I ride my mountain bike a lot around Portland too, but I can't say I have noticed any bike lane sensors yet but I will have to look for them as there are plenty of bike lanes here. (then again, I am usually up on the sidewalks keeping away from insane and inattentive SUV drivers .. .lol  (and yes, it IS legal to do so here in Portland as long as you give way to pedestrians)

[WFO]

http://www.instructables.com/id/Trigger-GREEN-Traffic-Lights/?ALLSTEPS

Check it out:

http://www.metacafe.com/fplayer/828731/trigger_green_traffic_lights.swf

Hope that helps 

SD

Checked the link but there link is dead so i found my own
Damn cheap! it might be worth a try atleast.

http://www.kjmagnetics.com/proddetail.asp?prod=BX041%2DN50&cat=168

[strangedaze39]

Hey WFO, the link I posted wasn't for buying it rather how to make them. IMO this is the best place to buy these.

http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=329-044

Parts express is a very good company, I'm just kind of weary about shopping online with companies I'm not sure about. Although your site would be better and cheaper not sure on quality? Do you know if they're a good company? It would be awesome to find a place with dirt cheap shipping on these as-well.

I'll definitely being trying this out since the light by my house always gives me this problem and report back.

Thanks for heads up on the link,
SD

[WFO]

Ohh i know i was just adding to by providing a source to buy them if people wanted to give it a shot the link in his video post was dead also in his link his magnets provide 6lbs a pulling force of over 6lbs those ones i surfed up have 23 lbs more would be better i would think also i would think a Neodymium magnets with a magnetic field is all one would be looking for .

[snarferer]

Aren't the frames on our bikes made of steel?...... If they are, wouldn't the sticky tape be completely useless?

[WFO]

Aren't the frames on our bikes made of steel?...... If they are, wouldn't the sticky tape be completely useless?

That's what i was thinking i would think the magnet alone would be enough to keep it in position but maybe hes anal retentive?

[mystic_1]

Tip:

Disassemble old computer hard drives (the older the better) to harvest some very strong rare-earth magnets.

mystic_1

[Topher]

Ok, so we buy some bulk magnets from magnets.com and some velcro and start marketing the SOHC4 green light foot trigger. We can also sell a strip of steel to mount in your garage to attach your riding boots to when not in use!
ODOT is right. The sensors measure inductance, which is changed by a magnetic field. The wire that is shoved into that groove in the asphalt is actually a long coil of wire. Perfect place to put your foot.
Might actually work to wear steel toe safety boots.

[paulages]

I teach electrical apprentices here in Oregon. Many of our electricians are hired to install these sensors, I've even install one myself. Knowing how they work, I thought I'd buy on of those triggering devices (a different brand than the original post). It's just a strong magnet, which would work if it could somehow be isolated from the rest of the bike. Since it's attached to the bike (separated by a plastic case) it adds it's magnetic field to the bikes field. This is a bit like peeing in the ocean to try and change the tides. I did notice an improvement on a couple of signals around Portland, but I still found a couple that wouldn't trip.

i had one of those on my bike until it fell off, and it definitely worked. i routinely ran the light at interstate and albina by my shop until i got one, and suddenly the light started changing for me. there's a magnet shop (yes that's all they sell) right around the corner from there on thompson that sell the rare earth magnets for about a dollar a pound rating. a 5-6# magnet isn't gonna fall off the bottom of the bike, and will definitely be stronger that the one sold as a "green light trigger."

[MoTo-BunnY]

Tip:

Disassemble old computer hard drives (the older the better) to harvest some very strong rare-earth magnets.

mystic_1

Well, I did just that, yesterday! Actually, my neighbor did - he's a total craphound / junk hoarder and I asked him for the oldest junk hard drives he may have laying around. Sho'nuff, he pulls out two of them in minutes and disassembles them for me (something I have never actually done even in 10+ years of being a techie!)

I am going to put them on the frame bottom and check out how/if they work on the aforementioned problem light sensor thingies here in Portland and dutifully report back with my findings! 

(by the way, you are very right in that these are some HELLA strong magnets! While I was taking this picture, I had two of them snap together suddenly WITH MY LEFT INDEX FINGERNAIL BETWEEN THEM - *** O U C H ***   much profanity ensued. . ..     )

[mystic_1]

Excellent.  Never tried them as green-light triggers but I have several that I keep in the garage for miscellaneous purposes.  Let us know how they work for you.

cheers
mystic_1

[strangedaze39]

Good idea Moto-Bunny! I can't wait to try, I bet a lot of us have old hard drives laying around to donate for magnets if it works well.

Thanks for the idea :-)

[mystic_1]

If you can lay you hands on an OLD 5.25 inch hard drive, the magnets in those are monsters

mystic_1

[FargoFour]

In North Dakota a bike can go through a red light after two cycles, if you're in a turn lane. Otherwise I believe it's a case of proceed when safe.

bud.

[bistromath]

You will want to take the metal backing off those hard drive magnets, if you can, or else put them metal-side-to-the-bike. Otherwise, the field will be essentially contained. Best thing is to have the magnet in free space WITHOUT being attached to the frame, but it'll still work okay when attached.

The coils work, as mentioned above, by measuring the change in the inductance of the loop caused by having a large metal object above it. Similar to a metal detector but I don't think it uses a transmit coil like decent metal detectors do. A magnet doesn't really change the inductance of the coil, I don't think, but rather interferes with the sensor circuit by generating a current in the wire as you approach the coil, which seems to be enough to trigger it. So if the sensor still doesn't see you after you install the magnet, try rocking back and forth a bit across the wire, or approach known trouble lights a little hotter than you usually do. The closer the magnet is to the ground, the better it will work, by an inverse square law, so small changes can make a big difference. That "magnetic heel" idea might not be so bad! 

[MoTo-BunnY]

Good idea Moto-Bunny! I can't wait to try, I bet a lot of us have old hard drives laying around to donate for magnets if it works well.

Thanks for the idea :-)

all credit goes to mystic_1 for the idea (see his earlier post in this thread) 

[mystic_1]

You will want to take the metal backing off those hard drive magnets, if you can, or else put them metal-side-to-the-bike. Otherwise, the field will be essentially contained. Best thing is to have the magnet in free space WITHOUT being attached to the frame, but it'll still work okay when attached.

The coils work, as mentioned above, by measuring the change in the inductance of the loop caused by having a large metal object above it. Similar to a metal detector but I don't think it uses a transmit coil like decent metal detectors do. A magnet doesn't really change the inductance of the coil, I don't think, but rather interferes with the sensor circuit by generating a current in the wire as you approach the coil, which seems to be enough to trigger it. So if the sensor still doesn't see you after you install the magnet, try rocking back and forth a bit across the wire, or approach known trouble lights a little hotter than you usually do. The closer the magnet is to the ground, the better it will work, by an inverse square law, so small changes can make a big difference. That "magnetic heel" idea might not be so bad! 

I was looking at www.greenlightstuff.com and their faq says the following:

Q: What are the two things I need to know?
A: 1) Do NOT mount the Trigger in a place that gets very hot (like near the exhaust headers). 2) The Trigger needs to be in motion to work. Drive over the sensor traveling about 5-10 mph (but stop safely.)

So it sounds like bistromath is correct, the magnet moving across the sensor coil induces current thus triggering the light.  I wonder, then, if it would be good to have more than one magnet, one in the front of the bike and one near the back of the bike, so that when you pass over the coil you generate TWO pulses, increasing the chance if triggering the light.

This also supports the idea that bigger magnets are better in this case, and as bistromath said the closer to the ground, the better.

Their FAQ also says:

Q: Wouldn't one of those heavy-pull magnet assemblies work better?
A: Actually no. Lifting assemblies are made by enclosing a magnet in a frame of steel plate. The magnetic field tends to stay inside the plate rather than spreading out into the surrounding space. The result is a high field density between the assembly's poles but very little elsewhere, so you get a strong magnetic pull, but only up close. The flux isolation base of the Green Light™ Trigger is designed to hold the Trigger magnet away from your bike's frame, preventing that kind of field collapse.

So, remove the metal base-plate on the HDD magnets, and create your own "Flux Isolation Base!" with a piece of two-sided tape.   If you're feeling fancy, epoxy the magnet to a suitable piece of plastic and attach that to a convenient bolt under the bike.

Perhaps attach the magnet to the oil pan drain screw, thus killing two birds with one stone?    The drain plug screws into aluminum so this shouldn't alter the field too much.

mystic_1

[WFO]

Ok i have figured out if i overwhelm the sensor with a 50lbs magnet it will not only change the light but change it to different shades of green  but sadly i seem to get stuck on sewer lids, it really freaks people out when the bike just stands by itself. But on the other hand i keep the street clear of ALL nails and sharp objects.




Now i have to figure out how to tuck away those unsightly wires away.




j/k 

[mystic_1]

Ha ha!  nice

I suppose one could also bolt a 50lb slug of steel to the bottom of the bike, that should up the inductance some


mystic_1

[MoTo-BunnY]

So, remove the metal base-plate on the HDD magnets, and create your own "Flux Isolation Base!" with a piece of two-sided tape.   If you're feeling fancy, epoxy the magnet to a suitable piece of plastic and attach that to a convenient bolt under the bike.

Perhaps attach the magnet to the oil pan drain screw, thus killing two birds with one stone?    The drain plug screws into aluminum so this shouldn't alter the field too much.

mystic_1

I am thinking of instead, installing a high-voltage "flux-capacitor" so that when I approach a red light, I can go "back to the future" where the light has already changed to green!   







(hmmmm. . . .how am I gonna fit all this on my bike. . . . saddlebags, YEAH, that's it. .  . . BIG saddlebags.  . .  )

[Topher]

Sorry, that De lorean is stainless steel, won't work.

[jbailey]

It depends on the bike.  My '75 550 trips most lights.  I have only gotten stuck twice.  I usually just run the light in that case.  My Kawasaki Concours has never had a problem.  My Son's Suzuki Vstrom has many problems.  The Concours is made out of lots of Iron and steel.  The Vstrom is mostly plastic and aluminum.

[MoTo-BunnY]

So, upon recommendations of using old hard drive magnets for my home-made light trigger (thanks, mystic_1!!), I am pleased to report back with the following updates:

I used the hard drive magnets and mounted them to my bike (rather stealthily) for my own home-made green light trigger thingy, and after testing the setup all summer (i.e. to lazy to take pictures and post a follow up I am most happy to report that THEY WORK GREAT!!!





Here are the hard-drive magnets I traded a beer for, from junk collector neighbor. This is three drives worth! (they were all like 500mb size or something - ancient!!!) I ended up taking them off of the metal plates - they were glued on but came right off.

I decided to mount the magnets on the center stand feet, so that I could lower them right next to the ground, if necessary, which later proved to be ideal. The magnets at the '4 o-clock' position, in the picture above, went inside the left foot of the center stand, the other two bigger magnets went into the right foot.







Here is the left foot of the center-stand - with the two magnets tucked inside. They snapped against the metal and since they were so enclosed, I just left them like that. Months later, and they are still there! This is also shows how I use the trigger, by the way. I pull up just shy of the magnetic loop in the pavement, off-center (as recommended on the Oregon DOT site). I use my left foot to push the center stand down to the pavement and then roll the bike over the loop, kinda lightly dragging the center-stand feet. It's real easy in use - easier than it sounds, actually.







Here are the magnets mounted on the right foot of the center-stand, with stainless steel wire. They were just the right size and mounted snugly on either side of the tube that runs down the center of the foot. The wire is probably overkill, but they aren't going anywhere now!







Here is the right foot with a quick shot of flat-black paint. Up underneath the bike, the magnets are now near invisible.





So this setup has worked AMAZINGLY!  With just having the magnets there, I noticed some of the previously troublesome lights would trigger, but some still wouldn't - until I dropped the center-stand. When I would do that, so the magnets are right above the pavement basically, ALL lights would trigger - EVERY LIGHT I HAVE EVER HAD PROBLEMS WITH, NOW TRIGGERS - EVERY TIME!   yaaaaay! thanks everyone for the suggestions and this thread.

Lights that wouldn't change for me, were SUCH a pain in the bum before but not anymore! AN EVERYDAY AGGRAVATION, GONE!  THANKS SOHC4.NET!!!