Red Light Answer

[Mike Gray]

This seems like an intresting subject. I can't figure why the red comes on at the second yellow when the car appears not to move at all, it doesn't appear to even be loading the convertor. When I watch the video over a few times in full screen, you can see the flash reflected on the pavement. Since he has polished or chrome wheels it seems possible the wheels reflect the light causing the eye to read that the car has moved.
If this wasn't possible why do a lot of cars have the ugly flat painted front wheels.

[Bernie Cunningham]

As far as I know, that type of sensor is no longer used, as in where light reflections or flashes would cause them to 'switch'.

These days the units are a sender and receiver across the track and must communicate with each other to 'switch'

[Mike Gray]

Originally Posted by Bernie Cunningham

As far as I know, that type of sensor is no longer used, as in where light reflections or flashes would cause them to 'switch'.

These days the units are a sender and receiver across the track and must communicate with each other to 'switch'

So when the funny cars take out the 1/8 mile and finish line foam blocks there is not just a reflector in the blocks but a receiver or sender?
Did it use to be just a reflector? maybe that's where the idea of wheel reflection got started.
Camera flashes for an instant are very bright, I hate the annoying flashes from overhead strobes at NBA games that are triggered by the photographers camera.
If I watch a replay in slow motion it will white out my tv screen.

[Jeff Stout]

I dont know the equipment at Pomona but what I know the reading device is in the middle on the starting line and when the car is staged it would block the camera flash that is shown in the video. The camera flash may have shined onto wheel but its the wheel facing the outside portion of the lane and would not interfere with the sensing beam. Now the rest of the increments down track have a reflector in the middle and the reading sensors are on the outside of the lanes.Doesnt solve the problem here but I think I would rule out the camera flash. As Don described his problem in WY I would have liked to have seen the tree activate again as the Camaro was still staged when tree was cleared just to see if car was at fault.Just a thought: if the beam is .030 in diameter and the wheel rolls just enough lets say .030 and keeps beam from crossing track and the car would move backwards (somehow?) say .001 then the beam is now uncovered and would register as if nothing was on starting line and go red. Cant be seen with naked eye. Sounds pretty far fetched but maybe.

[Bernie Cunningham]

Originally Posted by Mike Gray

So when the funny cars take out the 1/8 mile and finish line foam blocks there is not just a reflector in the blocks but a receiver or sender?
Did it use to be just a reflector? maybe that's where the idea of wheel reflection got started.
Camera flashes for an instant are very bright, I hate the annoying flashes from overhead strobes at NBA games that are triggered by the photographers camera.
If I watch a replay in slow motion it will white out my tv screen.

Really !!!! yes they are reflectors, all can see that and they continue to pose issues at the top-end. HOWEVER. we're talking about the starting line here ??????????????

Sorry about ya NBA problem !

[Mike Gray]

Originally Posted by Bernie Cunningham

HOWEVER. we're talking about the starting line here ??????????????

I know, just thought I would take a jab at the FC's.
Now if the side that reads the light is on the outside and it reads a light source there could be a problem with a camera flash, not to mention the DISTRACTION to a driver trying to cut a good light.

[Bret Kepner]

Having conducted my own Drag Racing School for fifteen years, it astonishes me how many veteran drag racers still don't understand anything about the starting line electronics array.

Pat's information is absolutely correct. The Stage-Loc system does not rely on a receiver since it has no function in the timing system; it merely keeps the "staged" bulb illuminated even if the front wheel has rocked back out of the actual "staged" beam. I'd venture a guess more than ninety percent of all racers have no idea the Stage-Loc system even exists let alone how it works.

In 2011, all NHRA National Event facilities have Stage-Loc and it's usually a permanent function requiring no activation. This means it is also functioning at regular events at most of these tracks.

Concerning the infamous "stationary red light", Jeff Stout's assumption is not fiction but fact. If the front wheel vacates the beam for a thousandth of a second, a red light will register. It has been proven a "flicker" of the "staged" bulb for less than two hundredths of a second will not even appear in the bulb since the filament will not have cooled before the electricity resumes its current through the filament. A flicker of three hundredths or less will not be apparent to the naked eye so nobody will see it, anyway. The vast majority of all video cameras record at a rate of one frame every 0.040 seconds, (four hundredths), so a flicker of less than that amount will not be visible on video, either.

Sun reflection is still a (rare) problem at some tracks but the effect has been reduced by variable infra-red frequencies used in the system. I still race at a few tracks with the old "headlight and photocell" arrangement and these problems are much more common with forty year-old equipment.

Hang in there, Pat. We'll keep you distracted as long as we can!

[Mike Taylor 3601]

Pat,
I'm sorry to hear about your loss,there is alot of things we never will know the answers to.
You and your family are in my prayers
Mike Taylor 3601

[Pat Joffrion]

Mike,

I didn't fully answer your question, so here goes:

The Stage-Loc and starting beams read only from the center of the starting line ... Not from the outside (as is the case down track). Actually, there is no outside lens for the Stage-Loc beam!

From looking at the photo, it appears to be impossible for the flash to go through the vehicle. Before I built my own track, I used to put shoe polish on the front rims because the starter told me that the bright sunlight might' ve caused my red light.

I found out the reason after investing millions. You guys get for free. Trust me, I know how it works and am glad to help answer your questions. Now, if someone can just explain to my wife and I the reason we have to bury our son tomorrow...

Chatting on this forum helps to get my mind off Philip's death, at least for a few minutes. Thanks for listening.

[Mike Gray]

Originally Posted by Pat Joffrion

Mike,

I didn't fully answer your question, so here goes:

The Stage-Loc and starting beams read only from the center of the starting line ... Not from the outside (as is the case down track). Actually, there is no outside lens for the Stage-Loc beam!


Chatting on this forum helps to get my mind off Philip's death, at least for a few minutes. Thanks for listening.

If the starting line beams read from the inside it doesn't seem possible that the light from the flash caused a false reaction. He would have to have been in really deep or really shallow to cause it to trip since the Stage-Loc was not on. (Assuming they have Stage-Loc at Pomona)
I raced up and down the West Coast and found all kinds of ways to loose but this one was new to me.

On another note - I am truely sorry to hear of the loss of your son. My son is only 13 and I can't comprehend what your family is going through. My condolences and exta prayers.