Experiences with traffic light trigger?

[srq68]

I zip-tied a hard drive magnet to my center stand today, I'll try to pay attention to see if it improves things.
I work late shifts and after midnight, many stop lights at major streets are trigger only, so I stayed and waited and waited, only to realize ther really was no one that late to drive up behind me on the loop and trigger it, so I drove through the red light.
The other embarrassing situation is at left turn arrows at big intersections, same thing, you're there, but the green arrow loop is not triggered, and cars behind you are begining to be P-O'd, so you make signal for them to get closer to the loop, which they don't interpret the correct way...

I work in airport operations and we just had a new access control system installed, with loops at all the perimeter gates, where you drive up to the gate (from the airfield side) and the gate opens. The old system's loops were too simple: you could throw a big set of keys or a wrench over the fence on the loop and sometimes trigger the gate to open...Ooops! The new one has several loops that work together to really detect a vehicle. The sensibility can be adjusted to various sizes of vehicles, i.e. a golf cart won't open the gate, but an aircraft tug will...

I'll see if the magnet works....

[fusionking]

I thot they worked like a metal detecter that you can buy yerself....only upside down!!??

[Bud Manley]

Originally posted by fusionking
I thot they worked like a metal detecter that you can buy yerself....only upside down!!??

basically yeah.
Just like metal detectors can tell what kind of metal they are being passed over by changing the resistance pertaining to the coil so too can they adjust themselves to prevent constant false signals by mufflers/brake dust etc...
the downside of this internal auditing is that they inevitably lose sensibility until a streetsweeper comes through and cleans it up. they then will adjust themselves for lower tolerance on the light triggering schematic.

Wow...after reading that I sound really smart.

[beechfront]

i have never heard of there being sensors in the ground here. to the best of my knowledge - motion detectors are used. i could be wrong though.


also aren't most stoplights on timers anyway? i have always noticed the behavior of lights changes depending on what time of day it is.

[rneal55555]

I've noticed quite a few motion sensor light here in southern ME and NH. Down in CT the majority of the ones I go through are mag loop sensors. I have one of those green whatever magnets you see on Ebay on my xs650 and it seems to help not perfect but better. For the money I guess it was worth it or then again maybe not.

[srq68]

Success

Well,
after a week's worth of driving back and forth to work on various roads and intersections notorious (to me) for not sensing the bike, I can happily testify that the hard drive magnet zip-tied to the center stand works real well!
Not one light failed to trigger, and some of them used to never detect me...