Height for IR leds light bridge ?

[demether]

Hi,

I'm finishing my track, and now it's time to build the IR led light bridge.

I don't know what the best height for it. :think: Any help will be appreciated :text-thankyouyellow:

[btaylor]

D-man, what system did you buy? if its trackmate, you can safely go 5 1/2 inches,( see the how to Harry did on this)
Mine is set at that hight and works flawlessly.
PitRow/TrackMate/TrackMate.htm

[demether]

I didn't buy any system, I'm building it. ;)

But basically, a light bridge is just a...bridge with powered LEDs inside it.

But I guess height could be important ?

[btaylor]

I looked at some matched sets of led's at radio shack a while back,and they had an operating range of 3-4 inches.
I guess it would depend on the type of emitters,sensors that you have.
Im no genius on this stuff,just passing on what i had read/done. sorry! not much help on this.
Bob

[demether]

Thank you for your try !

In the worst case, I will just take my tallest car (probably a chapparal) and simply make my bridge just enough tall for this.

[dr fabio]

If you have matched detector (photo transistor or photodiode?? what are you using?) and IR LED just do a simple test. Hook them up prior to mounting and test that that it works when seperated by a certain distance. Then progressively move the LED from the detector until it stops working. Then half the distance as your safety margin. In reality you should easily get away with 6" gap if you aim the LED correctly.

What are the part numbers of the detector and LED, they will have data sheets with the information.

[demether]

Thanks,

I can't remember the refs, i'll take a look tommorow (it's very late here in france). But the sensors and lights are matched, in fact it's the same brand, same reference, they are sold to work together (it's why I bought them).

Tonight I worked on the bridge, I'm not searching to make a "scenery" bridge, so I think I'll simply keep my first idea, making it a bit higher than my tallest car. I'd say, about 3").

[HomeRacingWorld]

Alignment makes the difference as mentioned. If you take the time to make sure they are as close to dead on as possible, you would be fine. I tested the Trakmate sensors and had them as high as 8 inches with no issues.

I would go at least 4 if possible. But follow the test advice and just find your desired location.

[demether]

"at least 4" : you mean 4" height minimum ? maximum ? Or the numbers of leds ? I'm using 1 led for each cell.

Concerning the alignment, I'm trying to align them the best I can, it's not perfect, I have to admit.

Thanks

[dr fabio]

I think the big H meant 4 inches. Or 100mm.

[HomeRacingWorld]

Yes, height minimum. 100mm. Thanks for helping Dr.

[demether]

Thanks !

Unfortunatly in the mean time I finished my bridge at 3" :oops:

I guess the idea is to avoid side lightning source (like lane 3 ir led lighting lane 4 sensor) ? It's something I thougth about...Once the bridge finished and glued :mrgreen: