*A bike light for UNDER R1000!!

[Marius]

Halogen Lights

Although these lights were primarily designed for off-road use, where they are almost universal, many commuters and transportational cyclists now choose to use high-power halogen front lights which operate from a NiMH, lead-acid, or Li-ion rechargeable battery pack.

The lights used by most halogen rechargeable systems are cheap, bright but fairly simple: they project a cone of light (wide and narrow beam options are available) which is good for off-road use but not ideal for road use as it can dazzle oncoming road users. This is why rechargeable halogen lights do not meet legal requirements in some jurisdictions.

Because they use standard commercial prefocused optics, a wide range of power and beam width combinations is available. Most systems allow simultaneous connection of different lamps - for example, a wide and a narrow beam for off-road riding, or a high- and a low-power beam for road riding.

Advantages of rechargeable halogen systems

    * Bright, sometimes very bright
    * Readily available
    * Can connect multiple lamps to one battery pack; provides flexibility
    * Reasonable battery capacity
    * Very reliable
    * Can usually be easily removed from the bicycle or to prevent theft
    * Lamps are cheap, widely available, and come in many combinations of power and beam width

Disadvantages

    * Relatively heavy battery
    * Limited run-time between battery-recharges
    * Hassle of being certain to keep batteries charged
    * Batteries have limited life, typically 500-1000 recharge cycles
    * Optics not optimised for road use

[aapjas]

IS MARIUS WALKING IN THE SAME DIRECTION SPEEDY15 WALKING IN???

 

 

 

 

 

 

 

Join us when we return after the break...

 

 

 

[Marius]

I've seen a normal Car light and I've seen a BMW or Merc light, there is a moerse difference.

[KlapperKnop]

my dad & i never built this light to impress other people with' date=' if thats what you're saying[/quote']  Speedi15 I am not saying that you built the light to impress people ... not at all!! I also do not say that you are doing the project to tell hubbers that people can be ripped off!!! No I do not say any of that ... but you should have done your project and never compared with BL every time you do a posting ... you could have bench marked yr light against any other light on the market; but you kept on comparing with BL's products ... which I found very irritating!

 

If it was never your intention, than SORRY for my perception I gather about you; but still as a 15 yr old, you seem to be very disrespectful towards adults; and this statement I can compliment the way you talk on the hub .....

[Speedi]

when have i been disrespectful? pls site any instances

[Brighter-Lights]

Marius,

 

You asked about the Firestorm hid but I replied with a 55w halogen vs Revelation-4 pic,  because it's the only comparison pic I have now, and because MTBR compares the Firestorm HID to a 40w halogen...

 

Till later

 

 

 

 

[Marius]

http://cvmtb.com/blogs/tech_talk/pages/hid-vs-halogen-vs-led-the-shootout.aspx on the bottum of the page is a YouTube clip compairing LED and HID beams.

[Marius]

No problem B-L!

[Brighter-Lights]

Thanx for the link, Will post a Light and Motion HID vs my LED's tomorrow.

Jo

 

[KlapperKnop]

when have i been disrespectful? pls site any instances

Look through the 22 pages where you reply to adults; how you address them; how you talk to them ...

[Marius]

L.E.D. vs. H.I.D. which is better?

High intensity discharge lights emit up to 6000k of light they are far more reliable than standard halogen bulbs which emit about 1500k to 1000k L.E.D. lights are new technology to compete against the H.I.D. bulb.L.E.D. lights are available on the lamborghini reventon and the 2008 escalade platinum.From what i have heard L.E.Ds emit a minimum of 6500k per headlight
so i ask you ppl which is better?

 

Best Answer - Chosen by Asker

higher color temperature 6000K or 6500K is not necessarily better, the higher the number the more blue it is.

the more blue something is, the more it hurts your night vision.
there is a reason they run yellow headlights in other countries.(4000K)

LEDs are typically going to have lower brightness with longer life if designed correctly, but are very expensive right now.

HID will have very high brightness, I really doubt anything will beat it for visibility anytime soon.

from wikipedia:
* 1700 K: Match flame
* 1850 K: Candle
* 2800 K: Tungsten lamp (incandescent lightbulb)
* 3350 K: Studio "CP" light
* 3400 K: Studio lamps, photofloods, etc...
* 4100 K: Moonlight
* 5000 K: Typical warm daylight
* 5500?6000 K: Typical cool daylight, electronic flash (can vary between manufacturers)
* 6420 K: Xenon arc lamp
* 6500 K: Daylight
* 9300 K: TV screen (analog)

[Marius]

Please bear with me, I'm learning

[Marius]

Question: How do the Lumens/Watt (if that's the right unit) of HID (High Intensity Discharge), LED, and Halogen bulbs for headlights compare? (For tail lights, it's clear that LED is the winner.)

Mountain Bike Review's <http://www.mtbr.com/spotlight/lightshootout/> light comparison clamis that the HID is about three times as efficient as the Halogens. They don't give a number for LEDs, and they're pictures of the output of various systems omits the LED systems. Are LED headlights producing enough light to see by, or are they still lights to be seen by? Who makes a bright LED headlight?

The HID systems are fearfully expensive (the cheapest MBR lists is $329, but Powerizer <www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=1398 >has a system designed to mount on a motorcycle helmet for $219, including a 4 hour Li-ion battery which weighs less than a pound, which looks like it could be mounted on a bicycle.)

David Wittenberg

 

 

To answer the original question, HID is the most efficient, followed by LED, and halogen is the least efficient of the three. But the issue is a bit more complex. HID is most efficient when used at high power, but it doesn't scale down very well. The lowest power HID light is about 10W, and they are much less efficient than stadium lights and car headlights. (Though still better than LEDs.) LEDs on the other hand are low-power devices, and don't scale up very well. The 1-W LEDs are very efficient, but the 5-W is less so, and there's nothing larger than that.

The other issue is voltage regulation. What I said about efficiencies assume you're operating them at optimal voltage. When the battery starts to die, voltage starts to drop, and efficiency of halogen lights drops rapidly. Whereas LEDs are equally efficient (actually, slightly more efficient) at lower voltage, and therefore continue to shine. That's one of the reasons why LEDs are desirable for safety ("to be seen") lights. In theory, both can be run at constant voltage (= constant efficiency) by using regulator circuits, but I don't know of any regulated lights. There are a few LED lights with regulators. All HID lights have regulators, so that's a non-issue.

This also means LEDs can have multiple brightness settings, and be equally efficient in all settings. When you try to do the same with halogen lights, you end up with decreased efficiency at the lower settings (i.e. a 12W bulb operated at 6W outputs less than 1/3 of full brightness). Also the color becomes more red at lower settings.

There are many other issues. For example, LEDs are sensitive to heat, and become less efficient (or break down completely) unless equipped with a proper heat sink. But if properly designed, they are extremely rugged and have long life. HID are more fragile, and replacement bulbs are very expensive. Halogen bulbs have shorter life but replacement bulbs are usually cheap. The cost of the light setup is of course much lower for halogens.

IMHO, lights with multiple 1-W or 3-W LEDs (or multiple lights) are the most practical. Unless you want a really bright light (twisty descents or mountain biking in complete darkness), in which case HID lights are better. My "commuting" setup usually consists of one Light & Motion Vega (rechargeable light with 3-W LED), one Cateye EL-400 as backup, and sometimes a pair of Cateye EL-120s, one on each end of the USS handlebar.

[ZorgusPrime]

If you can't measure the output current' date=' how can you do any calculation? You need the output current for every calculation in this case.

 

Measuring the volts on the LED won't help you with anything because every LED has a different forward voltage... some are 3.6v at 1000mA and others of the same manufacturer are 4.1v at 1000mA.

 

I just published my figures because if anyone really want to compete they'll post their measurements... because I know the figures I posted can't be improved.. unless you use a heavier battery... remember... that system was quoted to be even lighter than mine...

 

You'll see that running 1 led from a high voltage, the circuit is more efficient and that the low current on the battery makes the battery more efficient.

 

Running 2 LED's in series off 7.4 volt, you'll have linear dimming before the battery pack's empty voltage (even at 350ma)

 

Running 2 LED's in parrallel off 7.4v, you will have higher current drawn and less efficient battery. 

 

I run 790mA on the LED, so devide that by 2 =  395mA each for 2 led's.

 

Cree Q5's latest batches are all about 3.45v at 395mA and 125 lumens.

 

So 2 will be 250 Lumens at 395mA with a needed voltage of 3.45v+3.45v =   6.9v nominal for the LED's + at least 0.5v for the drop over the driver circuit = 7.4v

 

So 2 led's at even a low current of 395mA will only be in regulation until the battery pack reach 7.4v - then linear dimming wil start.

 

7.4v lipo is 8.4v full and 6.6v empty.

 

[/quote']

 

Hey B-L,

 

The current and voltage I can measure, but I unfortunately don't have a lightmeter.

 

Anyway, back to the calculations, you can't really go around saying "... because I know the figures I posted can't be improved...".

 

We'll I suppose you can, that's normally what causes someone to go out and invent something (and maybe that's not a bad thing :-) ).

Anyway, you do get Li-Po's at upto 200 Wh/kg these days, so theoretically you could  IVh/w, say 200/12.55*0.300*11.5= and get a battery of  215 grams to do the same. If someone was to go lower than that, then we can talk.

The proof is normally in the pudding, and that's why the beamshots are so valuable. I thikn we all look forward to seeing yours.

 

 

[sampie]

Wow, when i left for lunch it was on page 18.

[markStockton]

 

when have i been disrespectful? pls site any instances

Look through the 22 pages where you reply to adults; how you address them; how you talk to them ...

 

Speedi, it is a cultural thing. I myself didn't notice.