One spreads the beam more than the other. One is slightly longer than the other.

Isn't there two circuit boards in that one? I thought that there was a separate DC/DC converter board in the back and the driver board in the front. I believe that the heatsink is necessary.

 

It's easy to make it waterproof. I made my own mounting plate for the back and sealed it with bath sealant.

 

For £4 you can't expect too much, but there's no other way to get that many lumens per pound.

Edited October 5, 201411 yr by Ajax

I've uploaded a few photos showing what you get for your money. There are the 4 light emiters mounted on a single round metal plate, and then there's the volatage control circuit inside the main aluminium housing.

 

The heat sink must be a requirement, i guess. Although my present headlamp with admitedly less light, doesn't seem to require any kind of heat sink for its emiters.

I think mine's slightly different, but I can't look because it's sealed. I don't remember the thing in the heat-shrink being as big as that. I think mine's a single layer.

I think mine's slightly different, but I can't look because it's sealed. I don't remember the thing in the heat-shrink being as big as that. I think mine's a single layer.

 

Btw , that's one of those tiny new 5p's as reference, and the circuit inside is quite small.

Is there somewhere the equivalent (and small) for rear light at 48v?

 

thanks

Does anyone know if these lights really need the aluminium heat sink? It comes with thermopaste applied to gel the light circuit to the alluminum case, but i wonder if these lights get that hot in normal use.

In general LED lights do need a fair amount of heatsinking. With a halogen bulb quite a bit of heat goes out of the front of the lens, but with an LED it's all carried through the LED mounting star to the body of the lamp and then to the outside air. Any constraint to this flow of heat limits the lifespan of the LED.

 

The ideal surface area requirement is 10 square inches per watt of input power (assuming good thermal conductivity between the LED star and the light body). However this usually isn't practical so on a bike light there's a general rule that 1 square inch per watt works without too many problems given the movement of air over the heatsink (and our cool UK weather!). I'm running two lampheads at 8.25 watts each, and each lamphead has 14 square inches of surface area (not quite true - one has additional heatsinking for the driver, but close enough). Used them for the last few years throughout the winter and no problems at all.

 

Looking at the website stats of this light it says it draws 12 watts, so 12 square inches. I can't identify the type of LED to determine whether 12 watts is realistic - the only reference I can see is to "5050 LED lamp beads". If they really are 5050s then you really wouldn't need all that heatsinking as they will only take about 0.6 watts each - 2.4 watts total, plus the power dissipated by the driver, so figure 3 watts.

 

Any idea on what the LEDs are, or how much power they are actually drawing?

 

Michael

Any idea on what the LEDs are, or how much power they are actually drawing?

 

Michael

 

The only thing on the the board is JL L3575 .

I've tried to google this but so far no results on specs.

Own up, which one of you is this..

 

I've just recieved the light listed above, which is very bright when connected directly to my battery. I am thinking of taking it apart and putting the key componants inside my existing plastic headlight case.

 

Does anyone know if these lights really need the aluminium heat sink? It comes with thermopaste applied to gel the light circuit to the alluminum case, but i wonder if these lights get that hot in normal use.

 

 

Well the experiment worked, and I now have the guts of this new lamp

housed inside my existing headlight. Wow its bright!

 

Compared to my old light its almost .... too bright? I know with cars there would be rules on how bright headlamps can be, and rules governing the correct position for those headlamps.

 

Question.Can a bike headlamp be too bright? Has anyone ever been stopped because their headlamp, on a public highway, was considered a potential danger to on-coming trafic?

I definitely think bike headlamps can be too bright. A single XM-L LED can put out up to 1,000 lumens. A halogen car headlight bulb puts out 1,600 on main beam (and 1,000 will seem nearly as bright as 1,600 due to the way the eye reacts to lumens). Even if pointed downwards there's still sufficient spill of light to cause a nuisance to other road users.

 

There's been quite a bit of advancement in this area, with some bike lights starting to have specific road beams to put the light where it is needed. This has two advantages; firstly they do not dazzle other road users nearly as much, and secondly they make much more effective use of the light output from the light itself. The early Philips Saferide had from memory a 250 lumen output but it was far more effective in practice than the P7 flashlights around at the time (which had about 900 lumens).

 

Michael

I definitely think bike headlamps can be too bright. A single XM-L LED can put out up to 1,000 lumens. A halogen car headlight bulb puts out 1,600 on main beam (and 1,000 will seem nearly as bright as 1,600 due to the way the eye reacts to lumens). Even if pointed downwards there's still sufficient spill of light to cause a nuisance to other road users.

 

There's been quite a bit of advancement in this area, with some bike lights starting to have specific road beams to put the light where it is needed. This has two advantages; firstly they do not dazzle other road users nearly as much, and secondly they make much more effective use of the light output from the light itself. The early Philips Saferide had from memory a 250 lumen output but it was far more effective in practice than the P7 flashlights around at the time (which had about 900 lumens).

 

Michael

Isnt there a BS number or somesuch to make a light legal on the road?

Isnt there a BS number or somesuch to make a light legal on the road?

There is in Germany - StVZO German traffic regulations have specific requirements for bike light beams and it is these that have driven the likes of B&M and Philips to produce good optics. I'm not sure of the situation here in the UK.

My solution is 2 hope vision clamped to the forks.. they are bright, reliable and robust. Easily removable for security and swapping between bikes, and work from cheap rechargeable AA batteries which are swapped in seconds with 2 extra £1.50 battery holder

[ATTACH]9817[/ATTACH] [ATTACH]9816[/ATTACH]

Lets hope you don't bottom your forks out

Lets hope you don't bottom your forks out

I did wonder about that but it's easy to see how far they go with the clean line on the stanchions, and on my maddest of rides it doesn't go anywhere near....

I did wonder about that but it's easy to see how far they go with the clean line on the stanchions, and on my maddest of rides it doesn't go anywhere near....

Need to ride harder Phill

The clean lines are the competition bar, if you hit the top you get a big cuddly toy. Then again you won't be able to see it as your lights will have flung off already..

Need to ride harder Phill

The clean lines are the competition bar, if you hit the top you get a big cuddly toy. Then again you won't be able to see it as your lights will have flung off already..

I could always let some air out....

Let hope you don't bottom your forks out

 

Slightly underwhelmed you didn't spot my pun

Slightly underwhelmed you didn't spot my pun

LOL....

I definitely think bike headlamps can be too bright. A single XM-L LED can put out up to 1,000 lumens. A halogen car headlight bulb puts out 1,600 on main beam (and 1,000 will seem nearly as bright as 1,600 due to the way the eye reacts to lumens). Even if pointed downwards there's still sufficient spill of light to cause a nuisance to other road users.

ashlights around at the time (which had about 900 lumens).

 

Michael

 

Yes. I am also thinking about the effects of bright lights to on coming traffic in the rain. Its one thing to sell these things based on their lux per buck, but i wonder where the end users stand legally.

 

Maybe there should be a catagory of lighting refered to as 'off road' 'lighting, with an idea of what might be termed 'reasonable' lighting.

 

As most cities are preaty well light, it seems to me the real purpose of lighting is to be seen by other motorists without causing them momentary blindness.

Edited October 15, 201411 yr by Ajax

 

Any idea on what the LEDs are, or how much power they are actually drawing?

 

Michael

 

I spotted this on ebay with specs. It seems to be the same light at a much higher price, although they refer to a strobe mode which i can't figure out.

 

http://www.ebay.co.uk/itm/12V-led-head-light-super-white-e-bike-motor-bicycle-car-DIY-12W-Strobe-high-low-/151433937982?pt=LH_DefaultDomain_3&hash=item23422a843e

 

btw the included pictures will give you an idea of brightness.

Having seen these really bright lights whilst driving I would expect the user to be pulled up if spotted by the boys in blue simply because they are dazzling on coming traffic!

Having seen these really bright lights whilst driving I would expect the user to be pulled up if spotted by the boys in blue simply because they are dazzling on coming traffic!

 

Now i am stuck with how to reduce the lighting for normal riding.

 

Judging by the ebay spec sheet, the leds are BrigeLux 45mil chip,

which means each led takes about 3v. Which suggest with a 12v input, that they are being wired in series.

 

If they were wired in parallel i could remove 1 or 2 leds from the circuit, however if i did that with them in series, it would mean too much voltage to the remaining leds. I could try using resistors to divide the input voltage but the light's controller is there to normalise the output voltage at 12v.

 

This means the only way to lower the brightness is to put some gaffer tape over the headlight. Talk about Heath Robinson.

 

Can anyone think of a less current wasting method of lowering the brightness on these beads?

Ajax, it isn't really a case of lowering the brightness, but more of a case of lowering the beam direction so as not to dazzle people.