Techy, electrical type question - IR transmitter
 

OK, so what I want to know is... what do I need to build an IR transmitter - assuming that this is what I need to set off my lap timer.

At Brands in the pit garage, we could set it off with a TV remote.

So can I go down to the local electrical shop and buy some bits to make my own beacon??

If so, what will I need??

I can buy a 'proper' one for £40, but no doubt it's made from 50p's worth of parts.

Thanks ta :)

How about Maplins or RS? do they offer anything in their range?

So why not buy the cheapest remote off ebay and a stack of batteries?

Would a TV remote be powerful enough to trigger it at 100mph, 20 yards away?

I know nothing about IR, but assume that you may need something more than a TV remote?!?!?!

:lol:

Depends on the remote, but most will do 20 yards just about - try your own remote from the TV and see how far away you can get before it doesn't work ... you might be surprised!

The lap timer's eye is just looking for an IR beam, simple as that. A tv remote actually encodes some pulses into it (think morse code) but a lap timer isn't that picky, from what I understand - as long as it sees something it will trigger.

You could make your own out of some parts from RS or Maplins, and it would probably cost you less than a fiver. All you'd need is a small box, an IR LED, a resistor, a battery connector, maybe a switch to be really posh and some soldering skills!

Here you go -
http://www.maplin.co.uk/Module.aspx?...ia=ir&doy=23m6

Would it make any difference if you had 10 LEDs as opposed to 1? or is that like a false economy?

I suppose you could splay them in an arc so that the beam covers a bigger area?

Thanks for the help Ant :)

Kewl :D

Thanks

Is the 'beam' emmitted from the top of an LED, or just like a normal light bulb (in all directions)?

Found this too http://www.xs4all.nl/~sbp/knowledge/ir/ir.htm

Hi,

Saw a guy with a makeshift unit on wednesday.

Build a bank of about 10 infra-red leds (maplins) on the side of a box with a large alarm/bike battery in, put in correct resistors or regulator to lower the current for them and a switch. Should do the trick.

Andy

Cool. I'm up for trying this, but don't know what parts to buy.

Can someone link me to the correct resistor(s) to go with 5 of these?

Will a 9v square battery do the trick? or will I need 4 AA's - I don't know how it works with amps and volts etc.

If someone can give me a detailed shopping list, I'll buy it all on www.maplin.co.uk and have a go at it.

Thanks everyone. Really appreciate it.

Thinking about rigging it up in something like a Coke can or something, so that when Chass is on pit wall, he's not holding a beacon ;) Sneaky eh :D

Well first up, you need a 'receiver' not a transmitter, the beacon itself transmits the signal - the laptimer recieves it to trigger the timer.

Are you familiar with soldering, PCB (printed circuit board) design? Ok, there might be some PCB designs already on the web that will suffice but are you going to be comfortable soldering it all together? Given that too much heat will kill a component, and too little won't make a good enough electrical connection.

Hrmm? :D

It wouldn't actually be that hard I don't think - if you know how to do all those pieces. I was an electronics technician in a former life so if you're super keen I could probably help. Just not sure if I'd have the time really.

You're right, the cost of the components would be quite cheap - it's never really the parts you pay for when buying this stuff ... you're usually paying for the knowledge that some super geeky dude has when he dreams up this stuff.

twpd has experience of PCB design, a lot more than me, so he may e of some assistance. Antonye is also pretty handy in this area - fill your boots mate.

Increasing the number of IR emitters won't help, as they would all emit (roughly) the same distance of beam.

Depending on the scatter of the IR emitter, you could increase the number but I doubt it would be worth it. The dome in the top acts as a kind of lens to disperse the beam anyway - remember that it is a laser (but at a IR wavelength of ~940nm) and lasers have a narrow scatter; that is to say that the beam itself does not radiate from all over the emitter like a lightbulb does. It may well have a viewing angle, and you could possibly work out the size over coverage at certain distances, as if it was a spotlight, but I'd be tempted to just build the damn thing and test it!

All LEDs emit light from the top (domed) part, with the connections (legs) at the bottom.

Just stick it all in one of these boxes. Drill a hole in the side and push the IR led out and glue in place.
http://www.maplin.co.uk/Module.aspx?...sures&doy=23m6

You need to work out the voltage required by the IR emitter to power it, and add the resistor to drop any input voltage to that amount.

Too much power and it goes pop. Too little and it doesn't work.

Read this:
http://www.ngineering.com/LED_Calculators.htm

And this is the circuit you need ... I'm sure you'll be able to figure it out ;)

http://www.montage.co.nz/led/images/LED_CircuitPlan.gif

Ps: a = anode, k = cathode; check the spec sheet of the IR device to see which is which!

The problem with IR is that you can't see if it works - obviously, normal LEDs are much easier!!

You silly boy - I have a reciever. It's called a LAP TIMER!!

What I want to make is the bit that sits on pit wall - coz not all circuit beacons are turned on for trackdays and I don't have £40 to buy a Rollcentre one (which is made from £5 worth of bits).

Go to the back!! ;)

Thanks Ant - You're a star mate.

I did do this kind of stuff at school in technology (or whatever it was called) so I'm not a total muppet, but it was a looooooooooooooooooong time ago.

Cheers :)

My most humble apologies oh guru, please allow me to prostrate myself before thee and beg thy forgiveness!

Alternatively you could just pish off!

:D

:lol: Naturally ;)

;) .. I love you.

I have an AIM beacon and it uses 6 LEDs arranged in a 20 mm circle. It is powered by 8 AA batteries, or a 12V DC adaptor. It also has a low and high power switch.

I would imagine you'd want an LED with the smallest possible lens angle, maybe 15 deg, to get a well focused beam. It also increases the distance it can reach.

Nerd!

You've been on the juice haven't you!!

:lol:

Yes :D

Woohoo! First time I've used my Electronics degree for something useful since I graduated 10 years ago :D

Ummmmm...you don't need one. Every circuit I've raced on has had a transmitter in use on race days.

exactly ....

but Domski wants this for trackdays .. personally thats a **** attitude as trackdays are for fun, not for skimming the last 10th of a second from your lap times.

you have DD Domski, keep your racing there or book some ACU days as your average trackdaypunter doesn't want you out there pushing the limit ...

I didn't realise it was for a trackday - anyway it's next to near impossible to post fast lap times on a trackday due to the traffic so, why bother?

Oh for god's sake ...

How many 'trackdaypunters' do you see running laptimers? Heaps! I've walked around the pits on quite a few track days last year and seen loads of people with them, trying to hide them away.

Yes it's difficult to set a hot lap without disturbing other riders on track but you do get clean laps in the fast group so you do get the opportunity to have a go without impacting others.

I've ridden with Dom on a track day and I can vouch for him being a courteous rider who doesn't go stuffing the bike under people mid-corner etc. Track days help racers learn/refresh the circuit, it doesn't necessarily mean that you push every friggen lap and carve people up. In general it's the bloody hero's who think they are superfast that carve people up, not racers. There's exceptions to every rule ... JUST MY EXPERIENCE!

Just like legends who want 46psi in the rear so they can 'rear-wheel' steer the bike around in the novice group ... ;)

:lol:

I didn't realise you wrote the rule book for trackdays Dribble.

When I'm doing my 57 second laps around Brands Indy with my monsterous 60bhp missile, are you suggesting that the guys doing 50 second laps should be banned? What happens if they're having fun doing 50s laps, what do you do then?

Not only that my friend, but I'm not daft to think that I would get anywhere near my race lap times on a trackday. At Castle Combe I was doing 1m 26s on the trackday, and ended up doing 1m 22s in the race, and I had fun doing both.


:lol: :lol: :lol:

You're a funny bloke. Out there pushing it to the limit??? Give me a break. I don't do that in a race, let alone on a trackday.

Just for arguments sake, I'd rather have people with good ability out there pushing things to the limit, than a bunch of average trackday punters getting themselves in trouble and really causing a risk to everyone else.

...and not only that - If I want to make a timing beacon, then I ****ing well can!!!

Take your spoon elsewhere!

No I didn't, but they do exist ....

As for point two, thats easy, stick to racing and ACU days, you don't have to worry about your average rule abiding trackday punter or their ability ...

who cares if you build a beacon, build what you like, just use it at the appropriate time .. and thats NOT a trackday.

As for my spoon, don't tempt me !!!!!

TP, and why are these racers hiding their laptimers ?? and if they are just out there practising their lines and refreshing their knowledge, not pushing the envelope, why do they need them ???

The rules are their as they are deemed necessary to the punters safety ... you should know that better than anyone !!!

So you don't know how slow you've ridden around any track then?

You must be one of a kind.

Not saying it's OK to use them, but we all know that the rule about lap timers on track days is there because of insurance reasons.

in the main, no, i've never asked for anyone to time me, i've come in from a session to be told lap times but wasn't aware of being timed, the only time i've knowingly been timed was at CSS as they use timers in the States.

i do trackdays to enjoy, they arent an ego trip for me ....

talk to anyone thatknows me, maybe that does make me unique .. but i doubt it ...

Well just to set one record straight. I've never had a lap timer working on a trackday before. I've only bought one recently and it didn't work at Brands, and the battery was flat at the Castle Combe trackday (although the beacon was on). All I wanted to know was how to make a beacon, coz I can't afford the £40 to buy one from Rollcentre.

I think your initial post was not really on topic either.

I can see how you think that people trying to go for lap times can be a pain, but I would think that they are mostly in fast groups. Anyone going in a fast group should know the score and in my opinion, they have no right to complain about people riding too fast, unless it's dangerous.

I've seen plenty of slow people who are dangerous, and on the whole I think your argument is flawed. Not only that, you imply that I'm reckless on my DD bike.

The fact that you do trackdays to enjoy them - what does that mean?

I do trackdays to enjoy them too.

I do racing to enjoy that as well.

Just because I'm a ****load faster than you, doesn't mean I'm reckless or upsetting anyone.

Nobody has ever complained about my riding on a trackday, even when I've been timed, I'm curteous and aware that there are people like yourself out there, and I ride accordingly.

Basically, you're so far wrong on every aspect of your argument, and you ****ed me off!

I'm a good guy to have on a trackday and I am in full control of my bike, which is more than can be said for a lot of people.

FAR-Q

TP,

Do CSS still do timing?, went on Level 1 many years ago and they posted your lap times to you showing each session.

On the general topic of timing, sure track days are just for fun but part of that is trying different lines, suspension set up and so on. How the hell do ya know if that last click of yer suspenders has made the difference that yer mate claims is the reason he can do 10 laps in a session to your 5:D

If it isn't lap timers, it's mates with wrist watches, mobile phones, video cameras, egg timers and like who do the timing.

IMHO you can get "disrespectful riders" on circuit in any group with or without timing, it's what goes on between their ears thats the problem, nothing else.

Ray

On or off topic, its relevant in thisinstance.

I couldn't care that you are faster than me Dom, nice display of ego though, good lad.

Well, its nice to know no one has ever complained about you.

And why should "fast group" riders be trusted to flaunt what are hard and fast "safety rules" ??

And how can quoting the rules be wrong ??

as for ****ing you off, tough ****, deal with it, your disregard for the way you should conduct yourself is out of order.

oh, and please find where I called you reckless ???

TP,

egg timers, mates on pit wall etc do not have you distracted or as focusssed in my opinion as a lap timer does, in fact even in the briefings you are warned not to do that either, No Limits threaten to confiscate watches, mobiles etc... its a safety issue, if they didn't think it was it wouldn'e be an issue would it ??

as for people trying lines, set up etc, well thats cool, thats all part of a tracday so don't see the relevance of that statement.

As far as i'm aware the UK CSS does not issue timings on levels 1 & 2, i've never been issued any, maybe that was because they don't run lap times in hours ... lol

I doubt it. It will invalidate their insurance if it's found that timing equipment of ANY kind is bineg used.

and why do you think the inurance companies insist on it ???

because based on a table of probabilities and risk those running lap timers provide a greater risk, therefore become less attractive to both the insurer and the tdo.

the tdo COULD take a cover that would allow lap timers but then you're into "competition" territory and the premiuim rockets.

this like a lot of things is a catch all where the rules need to be written to protect us from the lowest common denominator, which in this instance is the idiot with a lap timer that is proven to be the greatest risk and the most danger.

thems the facts i'm afraid.

And Dom, before you get all paranoid and pee yer pants in anger no one is calling you an idiot.