New bike light :)

[gentlegreen]

I have to confess that a lot of this tends to get done on my desk at work.

My playing with lightbulbs and batteries at 9 years old is turning out to actually be useful 40 years later.

 

[gentlegreen]

Well, here we are, hopefully the last major modification for a while.

The brand new "55 candela" LEDs I got from Hong Kong for 30p each aren't actually that much brighter than the ones the ones I bought years ago from a chap on Ebay for 20p, but they're much brighter than the ones that come as standard in these UFO lamps.

That said, it's very difficult to judge with the naked eye as it's almost certainly far too dangerous to look closely at these things.



White LEDs have a forward voltage of 3 volts, so are best wired in threes for use with a nominally 12 volt battery.
These come with a free resistor suitable for connecting a single LED to a 12 volt battery, so I've used 3 resistors in parallel for each "triplet".

A bit daunting perhaps to solder together 48 LEDs, but I find it not too bad if I start off by painting the anode wires red and assembing them in sub-units - remembering the first rule of soldering that the joint should be mechanically stable in itself before applying solder to it.

£18.39 worth of bits and a few hours' assembly ....

 

[Boycey]

you should make a youtube video of your light projects with the aid of a smoke machine and include some comparisons with off the peg lights.

 

[gentlegreen]

you should make a youtube video of your light projects with the aid of a smoke machine and include some comparisons with off the peg lights.

Yep.

I really need to get my finger out. I would need assistance with the photography though as it's difficult to take meaningful photos of light sources.

Unfortunately I only have some elderly Cateyes myself.

I wish I'd kept all the various lights I've had over the years - or at least had photos. It's terrifying to think of the standard 1 watt EverReady lights I used in the early days - albeit powered by rechargeables.

I now have sufficient light that I can be sure they aren't the weak link in my armoury out on the road.

 

[gentlegreen]

all change ...

I have started riding on unlit paths and in groups, so I have had to modify my lighting strategy somewhat - after being repeatedly blinded by oncoming idiots with strobing white lights - and after one shouted complaint that my own high beam was problematic - even though it was angled down at the time.

On the roads, my large area lights front and back appear to do the trick.

Once on an unlit path with both pedestrians and oncoming cyclists I have been restricting myself to "dip beam" - currently a 40 degree LED spotlight firing down a tube, but hopefully next week I will have a brand new 25 degree lamp which will hopefully need less drastic beam-tweaking to prevent upwards scatter while doing a much better job of letting me see where I'm going.

I hope to fit a switch on my left handlebar to make it easier to switch the high beam in and out.

I find I miss the big 48 LED lamp for its ability to pick up those people who have seen fit to wear something reflective, so I have reintroduced my DIY 12 LED lamps. I'm planning to replace some of the blueish-white LEDs for some "UV" ones I've had lying around.

These currently come on with the 48 LED tail light, but I'm planning to come up with a less bright (diffused) second rear lamp as it's somewhat over the top when off-road .. much as I might take pleasure in discouraging the team jersey brigade and other random loonies from following too close.

Hopefully by the end of this winter, I will have worked out the optimum configuration and will be able to make a single, self-contained unit in glass fibre / resin.

 

[dlx1]

How about image from bike of how bright wide beam is.
if all are tuned on how far would beam reach in feet ?

I been looking at light but yet again they all seem over price and don't burn long! Just have one Cateye Hl-el135 ok not not the best for riding in woods.

May get one more. DIY yours don't think they would last bumping about off road.
Edit:
Been looking at DIY light on instructables.com

 

[Herbsman.]

Gentlegreen, you're a madman but a genius

 

[gentlegreen]

Annoyingly, though I have the battery power, they don't yet make a narrow beam MR16 LED more powerful than 4-ish watts... my 15 degree "high beam" isn't bad - though at the moment I'm only riding up a tarmac path through the woods at 7mph - not charging down rough paths at speed. I feel somewhat naked without the second one (soon to be 25 degrees).

There isn't really any problem with robustness if you don't actually need to remove them from the bike. I'm lucky in that most of the time I'm going from my house to a secure bike park at work.

Most DIY designs use multiple LEDs in a metal housing.



I reckon you can actually get away with more off-road - it's quite a job taming the beam patterns for road and path use ...

At the moment, a 25 degree plus a 15 degree MR16 lamp would come to about £40, battery £25, charger £15, plumbing fittings, wire, tape etc £10 - total £90

It isn't cheap, but it's a lot cheaper than the ready-made equivalent.

 

[UnderOpenSky]

You ever considered going into business? Even if you didn't want to compete with bike light manufatores, I'm sure there would be plenty of cavers who would be interested in good value, very very bright lights?

I settled on a 3W Nova+ after much research, just because there wasn't much choice in the sub £200 market.

Out of interest why do Watts seem to mean little when it comes to brightness? My nova is way brighter then my BD Icon, but they both claim to 3W.

 

[Herbsman.]

Maybe it refers to the amount of power being consumed (i.e. Joules per second) rather than emitted by the bulb.

 

[cybertect]

 

[gentlegreen]

LEDs are semiconductors and it's all about improving manufacturing techniques producing improving yields of brighter chips - with quite a price hike for the brightest ones.
And there are lots of variables when it comes to connecting a battery to an LED - they're usually powered through solid state switching regulators ...

I doubt that anyone else on the whole planet would actually want lights like mine - I simply grab cheap things off the shelves in Wilkinson's (and the breakfast table ), and can't compete with the likes of Cateye and Minotte - I actually have no deep understanding of optics - it's all "suck it and see".

 

[gentlegreen]

http://thecia.com.au/reviews/c/images/close-encounters-of-the-third-kind-4.jpg

Sadly this is why I can't use all my lights when on the cycle path when others are using it

 

[UnderOpenSky]

I doubt that anyone else on the whole planet would actually want lights like mine - I simply grab cheap things off the shelves in Wilkinson's (and the breakfast table ), and can't compete with the likes of Cateye and Minotte - I actually have no deep understanding of optics - it's all "suck it and see".

Don't knock yourself, looks like you've archived some impressive results so far. In terms of casing you could use an old FX2/3 or Oldham Mining lamp, you often see these dirt cheap on ebay or being given away on ukcaving as nobody wants old style bulbs any more. We really need to upgrade at work, but 15 new lamps + chargers don't come cheap.

I was looking at using one to mount a Cree LED, but abounded the project as I have no technical skills - unlike you!

FX3

Oldham

 

[gentlegreen]

The quest for lighting for all situations continues.

I have now acquired a third, Cree-based MR16 spotlamp - so I now have 3 different refractive optics to compare.

My old "low beam" - described by the supplier as "40 degrees" has only been left on for comparison. It doesn't contribute much that the 48 LED lamp does - albeit with a lot more oomph. I do like the smoothness of the beam given by its diffused optic.

Aimed at the middle distance is now their "25 degree" lamp which has an optic with concentric ridges. Unfortunately owing to a mishap with one of its pins (a key weakness of the design I have overcome by soldering wires directly to the internal electronics.

The high beam ("15 degree") is my least favourite so far - it has a clear refractive optic and a rather messy beam pattern with a lot of side-spill.

It turns out that the only supplier of replacement optics is a firm in Australia :-
http://www.cutter.com.au

Plenty of alternative optics to try in my perverse persistence in trying to use off the shelf domestic lamps for this purpose.

 

[gentlegreen]

Annoyingly the "25 degree" lamp doesn't behave much differently from the "40" - except for a less smooth beam pattern so I'll be ordering some replacement optics.

Though having another 4 or 5 watts up front won't make things any worse ...

 

[Lemon Eddy]

I applaud your madness, GG. Out of interest, how often do oncoming cars suddenly veer into ditches?

 

[London_Calling]

If you could just turn your attention to global warming for five minutes we'd be out of this pickle. Well that, or totally up the creek.

 

[gentlegreen]

I applaud your madness, GG. Out of interest, how often do oncoming cars suddenly veer into ditches?

I'm actually very well behaved in that regard

If you've ever cycled down unlit country roads, you'll know that cars don't dip their lights for cyclists - though I extract great delight from pointedly doing that myself.

Sadly it's other cyclists, off-road who are the worst culprits for dazzling each other.

 

[gentlegreen]

If you could just turn your attention to global warming for five minutes we'd be out of this pickle. Well that, or totally up the creek.

I have to confess that I did feel a bit worthy this first morning of the Copenhagen Summit as I overtook the stationary cars full of younger people.
Fat, middle-aged bloke on bicycle in the rain with lights he'd gone to the trouble of making himself.

My power input - 100 watts approx, average small car 40KW

Average amount of electricity used for my 20 watts max of lights - maybe 2 KWH per year.

 

[Lemon Eddy]

If you could just turn your attention to global warming for five minutes we'd be out of this pickle.

I second this request. Get onto it GG - and hop to it, we're in a bit of a rush.

 

[gentlegreen]

I've lost my revolutionary fervour I'm afraid. In the Hindu tradition, I'm steadily "retiring to the forest" ....

-----------------------------------------

The new intermediate lamp is frustratingly close to what I need. I've added a shade to try to contain some of the upward, wasted light. Hopefully it will turn out to be too deep, and there's wasted space in the plumbing fittings....

I have a mind to get the battery up front too - maybe come up with a bracket so I can securely slot the whole thing off and on.

The 40 degree lamp makes sense now - with the big front lamp off, or dimmed, there's a gap immediately in front of the front wheel ... so it looks like I'll just have to "put up with" 15 watts up front.
A fair bit brighter than a small motorcycle headlight.

The total 18 watts is still half what I started out with 15 years ago.

 

[London_Calling]

Impressive. Looking forward to seeing them in action.

 

[extra dry]

one little spill off the bike and all that time and effort will be lying in little bits along the road

 

[fredfelt]

gentlegreen - would fitting foil / reflective material around the cups / fittings help direct the light forward and make the brighter?

 

[gentlegreen]

one little spill off the bike and all that time and effort will be lying in little bits along the road

I haven't had a "little spill" in 22 years of cycling
And in the event of any accident sufficient to put it beyond repair, I doubt whether it would be my first concern.

As it happens, this is evolving into a one piece, robust package.

 

[gentlegreen]

gentlegreen - would fitting foil / reflective material around the cups / fittings help direct the light forward and make the brighter?

It's heading in that direction - I would probably use aluminised mylar as that is particularly relective.

 

[gentlegreen]

a teeny update ...

I have been giving consideration to the various different situations I encounter and the different lighting configurations required with a view to making the switching less like a pre-flight check and more instinctive ...

 

[gentlegreen]

A key issue has been the situations where my 48 LED "be seen" lights would upset other road or path users.
I had intended to simply fit a dimmer to them, but have come to the conclusion that it actually requires different lamps without the sharp points of light produced by LEDs.

The rear one I have fitted is a bit crap - a 21 LED domestic lamp wrapped in a surgical glove which looks faintly disgusting and hence needs further work ...

 

[gentlegreen]

For the front, I have ordered some 3 watt 12 volt compact cold cathode fluorescents - so now the front assembly has six lamps !

I may start to get banned from CTC rides.