Mounting a transponder

Mounting a transponder

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Discussion

BertBert

18,953 posts

210 months

Wednesday 1st May 2019
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MyVTECGoesBwaaah said:
A beam is used, it may be a bit hidden at some circuits due to their setup but somewhere like Croft for example you can see on side on a tripod in the infield near the start/finish line.

There is no beam for the other loops like sectors or pits however.
How does a beam differentiate between two cars or three cars crossing it at once? Is it actually a backup system for when a transponder doesn't work? If the timing system works for sectors without a beam, how does it work there if it needs a beam?
Bert

MyVTECGoesBwaaah

820 posts

141 months

Wednesday 1st May 2019
quotequote all
BertBert said:
MyVTECGoesBwaaah said:
A beam is used, it may be a bit hidden at some circuits due to their setup but somewhere like Croft for example you can see on side on a tripod in the infield near the start/finish line.

There is no beam for the other loops like sectors or pits however.
How does a beam differentiate between two cars or three cars crossing it at once? Is it actually a backup system for when a transponder doesn't work? If the timing system works for sectors without a beam, how does it work there if it needs a beam?
Bert
The beam can't; that is where your transponder comes in and you get the time from that when you cross the loop. I can't give a definitive answer as to what time it uses given it picks up multiple times as you cross over the line, however. That is perhaps where your positioning would come into play, but a camera is often used to identify who was actually ahead (The TSL Instagram has a few examples!).

If there was no beam, then any cars without transponders (Or issues with them) would need someone to identify in some way when the cross the line, possibly manual timing. As it is now, the beam does that as even if you don't have a transponder you will still break the beam. They wouldn't pick up anything at sector points as that relies solely on your transponder. I guess the reason why there aren't beams everywhere is setup and costs.

BertBert

18,953 posts

210 months

Wednesday 1st May 2019
quotequote all
So back to the point I originally made...

The timing does not need a beam to work, it works from the transponder alone to a timing accuracy of 1000th of a second. The question is how does it do that?!!

Bert

n3il123

2,601 posts

212 months

Wednesday 1st May 2019
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BertBert said:
So back to the point I originally made...

The timing does not need a beam to work, it works from the transponder alone to a timing accuracy of 1000th of a second. The question is how does it do that?!!

Bert
There is a loop in the circuit which when the transponder goes over the transponders code gets sent back to the timing computer and it associates the transponder. If the beam is broken with no transponder then the timekeeper can manually associate that broken beam with a vehicle. I think it all gets a lot more complicated when cars don't have a transponder and they over lap a broken beam. (thats my basic understanding anyway).

BertBert

18,953 posts

210 months

Wednesday 1st May 2019
quotequote all
n3il123 said:
There is a loop in the circuit which when the transponder goes over the transponders code gets sent back to the timing computer and it associates the transponder. If the beam is broken with no transponder then the timekeeper can manually associate that broken beam with a vehicle. I think it all gets a lot more complicated when cars don't have a transponder and they over lap a broken beam. (thats my basic understanding anyway).
Well I'm happy to be in the wrong, but I don't understand how multiple cars can go side by side through the beam and get different time readings. How does that happen?
Bert

MyVTECGoesBwaaah

820 posts

141 months

Wednesday 1st May 2019
quotequote all
The time is taken from when the transponder crosses the loop instead in those situations.

BertBert

18,953 posts

210 months

Wednesday 1st May 2019
quotequote all
MyVTECGoesBwaaah said:
The time is taken from when the transponder crosses the loop instead in those situations.
Sorry to labour the point, but in that case, why does it need a beam?

MyVTECGoesBwaaah

820 posts

141 months

Thursday 2nd May 2019
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I imagine the main reason is a backup; both the transponder and beam system is used together when they are working (With your time coming when you cross the beam) but having both at least gives an alternative should one or the other stop working. Another bonus of having a beam is cars without transponders are still logged (Unless they are side by side with another, which is when it gets complicated).