Red Light Answer
 

As a racer, I did not understand how just dropping a few RPM's could cause a red light.

Once I built No Problem, I discovered just how delicate the staging beams really are. After serveral customers were red lit by the tree (in the same lane), I took a Cajun approach. I used a dragster wheel to light the stage bulb, then back it up a hair-width, and the red light came on as the tree was activated.

This happened on more than one car, but all were using trans-brakes. In some of the instances, the reverse gear overrode the forward 1st gear, resulting the vehicle to back up a FRACTION OF AN INCH, which caused the red light. I witnessed the same occurance in footbrake cars that staged very shallow.

The solution was installed five years ago when we ordered the CompuLink Stage-Loc beams. Not a single reverse-action red light since then when using autostart. However, in the Jr. Dragster younger age groups, we still use a manual start because some of the kids would get auto-started in a timed-out situation. Some of the kids get the red light from the rocking of their small front tires. It's just the way it is.

Our Stage-Loc system will allow a driver to back up three inches once the tree is activated (after the last bulb is lit for 1/4-second). But you must remember that in order for Stage-Loc to be in effect, auto-start must also be in use. HOWEVER, even with Stage-Loc, if you light both bulbs first, then back out by just a fraction after your opponent has lit his stage bulb for 1/4 of a second, the computer fires the tree without seeing you in the beam, and you are red.

It cost me about $5,000 for the Stage-Loc upgrade, but it was worth the money. Not a single ***** chewing since it was installed. I can prove it to any driver... if you stage real shallow, just turning your steering wheel a little bit will turn on the red. Just backing off the converter will turn on the red. You need to check with each track to enquire if they are using the CompuLink Stage-Loc. If they don't have it, or are not using it, you could be SOL (and red).

I hope ya'll now know how the system works.

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Great info Pat. Thanks!

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So did the camera flash cause Mason's red light?
The next frame in the video shows his red light come on.
I assume the starting line reads from the outside the same as the downtrack lights.

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Quote from response by Mike Rice: "The shallow stage deal is very real, especially without the StageLoc program."

From Reading Mike's reply, it appears that Stage-Loc was not used. I was under the impression that all national event tracks had it installed years ago. However, it has to be set to be "ON" for each category in the tower computer.

If it was not turned on (per Mike's reply), then someone in the tower screwed up! Since the stage beam are recessed at least six inches inside of PVC tubing with less than three-eighths of an opening, I don't believe the camera flash could in any way reflect into such a small hole to reach the receiver.

Conclusion: Without Stage-Loc operating, the slightest movement of the front tire more than likely caused the red light. Kind of sucks to have the software disabled! I would recommend that someone needs to verify that it is enabled for stock and super stock at each race.

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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.

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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'

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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.

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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.

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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.

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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.

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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 !

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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.

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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!

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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

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Pat, thanks for all of the info. Can you tell me if it is normal for BOTH the pre stage and stage lights to go out when the red light comes on? I know it is rare that a car is still sitting there to turn on the stage lights when the red light comes on, but i would think that if I did rock out of the stage beam that the pre-stage light would still remain lit since the beam is still being broken.

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Yes the pre stage and stage beams will go off when the tree has been activated and something happens such as leaving and going green or leaving and going red. Then when tower resets system for next pair of cars and your car was on starting line it registered that the next car was up to line ready to go with both beams lit. I think in Mike Rice comments it explained that portion of the lights going off and back on.
I didnt give it any thought about the time it takes for filament to stop illuminating like Bret describes but math wise it would make sense that we didnt see it on film or it was that fast on then off then on again that the filament never stopped being lit.. I know this sounds like a reach but to me its the only way I could see it happening with reason.
When checking roll out at Speedworld I was able to rock our test wheel and get light to flicker or be solid lit or off. It took time to do it but I was wanting to get accurate reading to make lanes equal. Also Sunday team race in time trials I had a car run faster ET then it ever had and a 524 MPH time slip. One of two reasons a piece of paper or the large wind gusts and dirt devils we had shook the foam reflector in center of track making the sensor think something stopped the reflection after he crossed 1/4 MPH start clock but before he crossed MPH finish. I know it has nothing to do with problem at hand but a explanation of reason why it happened. Never had problem before and the next 6 hours of racing that day.
Jeff

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I'm not an electro-optic engineer, but I have worked in the field of optics and electronics for 20+ years, and I currently work for a company that makes optical sensors (our sensor works with a VCSEL in the IR-A range at about 800nm). In short, you CANNOT say WITH CERTAINTY that the photographers flash did not effect the receiving sensor. Optical sensors are pretty simple devices really, and as Pat pointed out in his original post the receiving sensor (detector) is a semiconductor device that is "tuned" to a specific wavelength of light. This helps increase the signal to noise ratio, and improve overall signal quality.

However, the match between the detector and wavelength of light that it is trying to detect is not exact, i.e. a sensor that is looking for a wavelength of light predominantly at 800nm doesn't usually reject wavelengths at 799nm and 801nm (it would have to be a REALLY high-dollar sensor). Optical sensors are typically open to a range of wavelengths, with their peak wavelength being the specified wavelength, or the wavelength at the center of a gaussian curve, like so:

http://hyperphysics.phy-astr.gsu.edu...math/gauds.gif

As you can see from the above graph, there is a rolloff that would happen with the wavelengths of light seen by the detector. The minimum and maximum wavelengths would be determined by the sensor manufacturer from the type of detector technology used, and the tolerances in manufacturing (which in the end is reflected in the cost).

The same is true for the emitter. Again, the output of wavelengths from the emitter is typically a gaussian curve with the predominant wavelength being the specified wavelength. This is even true for lasers, though with lasers the wavelength range is much smaller than non-collimated light. I don't know the exact type of light source that is used for the stage beams in the timing system, but I highly doubt that they are lasers.

So, how would the photographers flash possibly affect the detector? It all depends upon the wavelengths of light that is emits. What the human eye can see is light in the approximate range of 400nm to 750nm. Light with longer (IR, microwaves, etc.) or shorter (X-rays, UV, etc.) wavelengths than that range is invisible to the human eye. What we see from the flash is white light, which is made up of all of the colors of the spectrum over the visible wavelength range. This is why when you shine a white light into a prism you see the entire spectrum of colors (sunlight through water droplets forming a rainbow is the same thing).

So, from this fact alone you can see that the photographers flash does NOT output a finely tuned wavelength of light. What wavelengths does it output? Well, we can say with a high level of confidence that it outputs an approximately wavelength range of 400nm to 750nm, but wavelengths above or below that are unknown. You would only be able to tell ALL the wavelengths by looking at the output with a spectrometer. In addition, is it possible that the flash outputs the predominant wavelength that the timing system's detectors are looking for? In short, the answer is yes, but at what amplitude is unknown (one would expect that it wouldn't be a predominant wavelength, but again you'd need to analyze the output with a spectrometer to know for sure.)

What is also important to note is that just because the detector is mounted inside a box or tube does NOT mean that outside light sources can't impact their performance. Certain materials are invisible to certain wavelengths of light. The X-Rays are typically defined in the 0.1nm to 10nm range, and can pass through many materials. Most optical sensors use either visible light or IR, and IR can pass through materials as well (this is why the military uses IR sensors to image heat sources of bad guys inside buildings). A nice description of IR light can be found at the link below (take notice of the image of the guys arm inside a garbage bag).

http://coolcosmos.ipac.caltech.edu/c..._ir/index.html

Now, does all this mean for certain that the photographers flash caused this event to occur? Absolutely not, but from a scientific standpoint, it seems awfully coincidental that the photographers flash goes off, and immediately afterwards the red light comes on. I'd have to see the original footage frame by frame (you can't do this on YouTube) to see what the timing difference is because optical sensors are fast acting. If the timing difference is long (i.e. more than a few tenths of a second), it would seem likely to me that something else must have caused this to happen. But, if it is literally the next frame as somebody else posted, stray IR light from the photographers flash is a distinct possibility.

Would that mean that we'd all need to demand instant changes to the timing system detectors? No, because IMHO it would need to be a near perfect storm for this to happen. With ALL the rounds of racing, and ALL the pictures taken, how often have you seen this happen? It is obviously NOT a common occurrence. But, at that point we could at least say that we believe that the system is NOT perfect, and try to work on a better, more fool-proof solution (rather than just burying our heads in the sand and saying, "It's not possible for this to occur.")

Science lesson over...

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"Now that's what I'm talking about - right there" - Larry the Cabel Guy

LMAO

Thanks


:-) peace

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Man, with all them big words I would expect another visit from authorities in the near future....

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I don't understand that even with the pictures.

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If you look at the You Tube video in full screen then drag the small circle on the timing bar you can move ahead to the location of the run in question. Keep holding down your mouse and you can rock the picture back and forth. At 19:13 the 1st yellow is lit and the camera flash is visible at 19:14 it shows the 2nd yellow on and the red light on at the same time.
It may not be close enough to determine the length of time it took but I enjoyed the lesson.

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with your normal curve displayed, you have not given any evidence to say the flash has anything to do with the red light. You will have to do more research in order to make any statement of any kind.

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This is an interesting subject for sure. But, let's not overlook the obvious. What are the chances some electronic voodoo happened at exactly the same time this photographers
flash went off? About 14,000,000,000,000 to 1? (wait a minute, that's the national debt number). Anyhow, if they keep coming up with more doo-dads for the timing equipment
they will take away my last excuse for losing. Stage-Loc, Smage-Loc. Now, if we could just get back to the days of the crooked a## flag starter that would raise the green flag
when I left the starting line . . . . . . . . .

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What statement did he make ? He said it was a possibility, and it is more plausible than other statements made , such as the tire pressure changed, yea thats some quality research done there . Ill make a statement on limited research, ie looking at the video, that dude got ***#ED !!!

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Applying the "Occam's Razor" line of reasoning..."the simplest explanation is most likely the correct one."

The simplest explaination would be that the car did move slightly and the flash just appears to be a coincidence.

I for one did not know how the sensors are arranged on the starting line. I thought they were arranged as a sender and receiver.

Do I still think the flash caused the redlight.....Yes I do.

No one can say for sure what that flash might have refleced off of and the path that refelction took. It definately is less likely than the car moved but it still appears to be triggered at the time of the flash......

We need a government grant and a couple federal and state agencies to study this.....Should only take a few years for them to come up with an answer. A couple million $$$ should do it

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Jason Oldfield is talking WAAAAY over my head so I can't really comment on his theory. However, I've always held the belief if a photographer's flash could either match or override the frequency used in the infra-red sensors, there would be a few thousand more of these redlights than we currently witness.

I don't know the photographer shown in the image but, as much as I hate slamming anybody, he has no clue what he is doing. Anybody with any experience in this business knows you never actuate a flash in drag racing until the car leaves the line. When shooting handicapped eliminations, one never actuates a flash before the quickest car has left the line.

I also agree with Carl; we're losing excuses at an alarming rate and something must be done.

PLEASE HELP SAVE THE EXCUSES!

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Had something similar happen to me when running Jerry Stein's Max Wedge car a few years ago. Was getting used to it footbraking in heavy at Englishtown. All staged up second round, knew I was very shallow, tree comes down and the apple lights up. Never moved, just dropped the rpm and drove down track. Friend standing watching me do this later asked what happened: My answer was "a stone or cigarette butt fell off." Few years before when used to run my chevelle in heavy and advanced trophy Michael Napp stopped to look over my car in the AT lane making sure I was legal for the class. Conversation developed and he explained how this stuff can happen.

Agree with Bret explanation of the flickering bulb. Think Joe Sway of Atco gave me that lesson at my first bracket finals.
It's not unknown that a racecar can roll backward when applying the transbrake. Has to do with valve body, hydraulics and clutch engagement.
The flash of the camera may seem far out but a very good explanation of the possibility was provided.
With all the possibilities then what is the possibility that a stone was stuck to the tire, just happened to line up with the stage beam and then gravity took over and just fell off.

Sorry you got the short end, but in the end "just buy more tech cards" and one of these fluke situations may just go your way. ;) :D

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I'm with you Brett, Jason is way over my head too.
Does'nt it take infrared beam to activate system so other light sources can't activate it?
This story is'nt aimed at anyone just I thought it was funny.
Years ago my Dad hired a guy at his shop,He had told him how good he was ASE certifications etc. So first job for him was lady brought in car she said had a engine miss every now and then it would come and go,so the new guy checked it all out and came back to my Dad and told him what was wrong with it was it had a intermitten(spell?) problem,
Dad replied no ***** sherlock.

Another story I thought of was guy that burnt pistons in nitrous engine was'nt satisfied that he leaned it out sent pistons back to piston company to be analyzed, it was determined that engine was'nt lean after all,but had too much nitrous for the amount fuel being supplied. He was happy with that answer.`

Again this is not directed at anyone just adding to statement that was made about simplest answer is correct alot of times.

Did I see early in this post that He had redlighted at next race in similiar fashion?
I know all too well the frustration of redlights.
Mike Taylor 3601

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That's absolutely correct Mike. But, it is possible that the IR light could have come from the photographers flash, even though all we see is visible white white (I'll keep this short because if you want the whole description, you can go through my science lesson again).

In the end, as I said previously, in order for something like this to happen you would need to have a perfect storm of events take place. So, that's why I don't think we have, or will see it happen all that often. From my perspective, the simplest rule is to ask the photographers to refrain from taking flash photography directly at the line (i.e. shoot down the track all you like), or until the fastest car is in the process of launching (this obviously also eliminates the potential distraction issue for the drivers as well). If this were done, we'd never have to worry about anybody claiming that a photographers flash impacted the outcome of their race.

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Bret
At school you instructed us that we should be as shallow as possible every run. That way we know where the car is at the start of every run for consistancy. So if we are running at a track without a gaurd beam should we give it one bump past flicker to be safe or just assume that this is a 1in 10 million type deal and keep doing it the way you taught us. By the way any chance you will be doing the school somewhere else. I really enjoyed the classes that I went to and learned alot. I just wish I could have made them all but business has a way of getting in my way of doing stuff.
Rob

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Remember this debate?
Looks like it happened again at pomona.

"This will be the second attempt to run the final round, as it's reported that a photographer's flash created a red light in DeFrank's lane, as the tree came down right before the Professional final rounds. They were given time to cool off and are back to finish the racing for today."

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In My opinion that when this happens The driver thinks he knows what happened , The crew Chief thinks he knows what happened , The Starting line crew is a little concerned but thinks they may know what happened , all this is emotions now > but the $50,000.00 timing system knows what happened it was a red light no emotion there

Now since no other racer has gotten a rerun when this has happened the rerun that happened to Mike Cotten was the wrong decision made based on the pass decisions > now we have a whole new Problem that "will " come up when this happens again ????

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After sitting at a race track for the better part of a damn week , I feel if the car has not moved and the red light comes on it should ALWAYS be a re - run .... Obviously there is a problem with the system , or flashes or whatever.

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Maybe far fetched but food for thought. Has this problem only surfaced since the beginning of LED prestage and stage lights. Regular bulbs have a filament that that takes time to cool off and can be relit and not not be noticed by the human eye. Not so with a LED . much faster on/off. Example - LED brake lights and why they use them today. Could be a tie in with the electronics ?

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The one that happened 2 years ago was the old style stage lights.

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The Defrank car has smaller tires on the front. And the way these cars are built today they sit very low to the ground so the pre-stage and staging beam have to be fairly low so the front end does not trip it. (not sure what the standard height is). With that in mind when shallow staging there is less circumference of the tire blocking the beam. When setting the trans brake most feel that your car won't and can't move. When staging you set the trans brake, during that time you are waiting to release the button. If that car with small tire moves .030 or .050 or .100 for what ever reason, more back up pressure applied than forward, wind, etc ... do you think anyone would be able to actually see that movement, but that may be all it takes to light the red light by allowing enough of the beam to make contact to the outside cell.

So what you have is a 900 hp car that is relying on a trans brake to keep it from moving in either direction ..

just a crazy thought ...

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Right, Chuck. ...and on top of that, the car shakes from being on the rev limiter.

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Makes more sense to me than a camera flash....every posibilities should be examined and a solution found to eliminate this type of red eye.

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Ground clearance is required to be a minimum of 3". Stage beams are roughly 1-5/8". Yes, transbrake cars can back out of the beams. It happened in Super Comp at Gainesville last weekend, and it was recognized for what it was. That is a different animal. Again, all of these videos of similar incidents show the red-light coming on BEFORE the pre-stage and stage lights go out. Additionally, one of the examples of this phenomenon was with a footbrake car that staged at a low rpm and then came up on the converter, which results in the car moving forward slightly in the beams. While red lights are possible by rocking back out of the beams is possible on systems not utilizing Stagelock, this is demonstrably a separate issue.

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It is and was common practice for many people running doorcars with trans brakes to apply your line loc along with the trans brake. It will help to stop any movement once the brake is set and your staged.

The Defranks could not win as much as they have unless they had all their ducks in a row as the saying goes.

In 1970 at Atco in the first round of stock my partner was redlighted for this exact scenario.....slight movement backwards but it was a stick car and the starting line probably had a slight dip in it....and we did use a line lock to try and hold the car.....it didnt prevent that one......