| SCD |
Hello out there:
I have recently been riding with a couple of guys that have these incredible lights. The lights are Xeon High Intensity Discharge. They are sold by a couple of companies and are ridiculously expensive. So I was wondering if any one had DIY'd a set yet and was looking for some help in getting parts. I have made a few other sets of halogen lights but this looks like a bit of a different animal.
Any help is greatly appreciated. |
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| AndrewT |
Hi,
go on , give me a lesson in modern lighting.
Is that Xeon or Xenon? Because Xenon lamps are high pressure discharge lamps, a completely different animal as you put it.
What are the new lamps being fitted to automobiles? Are these them? |
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| Variac |
I believe the bike lights he is describing are the samee tech as those new HID auto lights that are white/blue. (not the white/blue fake versions)
SCD,
I would first find out from your friends how much the replacement bulb would cost. That might be the first limiting factor. Lots of bike riders here, so there will be some interest. The people that will know the most will be the in the video-moving image forum. |
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| SCD |
Thanks Variac.
I have begun that path as well the two companies I am aware of generally only sell replacement bulbs to purchasers of their product (kind of makes sense, keeps guys like me out of their hair).
I suspect the bulb will be available from a supplier it is just a matter of finding out whom that supplier is.
As far as I can figure out so far it is a 13 watt bulb that operates at ~ 13.4 volts. The lumen output is pretty high somewhere near the equivalent of a 45 watt halogen MR11 bulb@ 6volts. The retail price is crazy, I suspect the availablity of the bulb will control the DIY crowd for now.
I will keep trying. There are many creative people out there
Thanks for the help |
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| Variac |
| Well, your friends who are purchasers of the product might be able to get one for you. There must be some kind of high voltage ballast somewhere I would think- I don't know though. The video projector folks are always talking about ballasts for their bulbs... |
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| wes-ninja250 |
HID bulbs do indeed required a high-voltage ballast. Just a hint for auto types, if it doesn't cost at least $300 US for your first light, it's not an HID system.
There are many vendors out there selling out-of-spec halogen bulbs with a blue tint. As a bonus, the inert gas they choose is often Xenon. People think these are HID. Unscrupulous vendors have been known to call them HID conversion bulbs or similar. But, the fact of the matter is, they aren't HID!
In fact, the biggest difference between HID and incandescent bulbs is that HID bulbs have an electrical arc in place of a filament.
Wes |
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| AndrewT |
Hi Wes,
are you confirming that HID is a development of the Xenon high pressure discharge lamp, presumably done on a small scale to suit automobiles and push bikes? |
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| wes-ninja250 |
Andrew:
I can definately confirm this for automobiles, but not push bikes. Given the electrical requirements, I find it difficult to believe that they exist for the latter.
They come as OEM equipment on certain high-end autos. They cast a blue-white light, and will not have high/low-beam (dip) functionality integrated into one housing. Where this is desirable, motors have been used to raise/lower the enclosure.
Notes for anyone wanting to "convert" their car -- optical requirements for an incandescent filament and an HID arc are VERY different!! An effective kit would have to include:
- Reflector
- Lense
- Bulbs
- Ballast
- High/Lo beam solution
- Wiring harness
Daniel Stern, a very smart (professional) automotive lighting guy, discusses this at length: http://www.danielsternlighting.com/...onversions.html
Wes |
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| wes-ninja250 |
After some Googling, I take back what I said about bicycle HID lights. It seems they do in fact exist: http://www.bikelights.com/Products/arc_li_ion.htm
At $580 US (300 pounds?), the price is at least in the right ball park.
Me, I'd have a hard time spending that kind of dough on a BIKE, let a lone a light for one! :)
Wes |
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| SCD |
Yes the lights are Xenon. 13 watt consumption @ 13.4 v DC
Yes folks the lights are for "push bikes"
Yes they are ridiculously expensive
That is why I wanted to find out if any one had taken on the DIY challenge yet. It seems that no one here has yet.
Thanks for the interest.
I will keep looking |
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| bentheboatman |
Follow this link and you should find what you are looking for
http://www.batteryspace.com/index.a...ROD&ProdID=2204
I'm scratching about with the idea of HID, not sure if this site provides the ballast as well
I have found some pretty good Luxeon LEDs which provide enough light for road use. You can buy them at any electrical store.
Cheers
Ben |
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| Variac |
Supurb detective work. I've been riding a lot more lately and a great light would help in the winter. A friend of mine just paid $380 for one. It is very slickly designed, and amazinly bright, but more -it has a wide beam. We can do something cheaper and maybe better I'm sure!
BUT they have assembled systems at great prices- might be hard to top:
http://www.batteryspace.com/index.a...TS&Category=738 |
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| SCD |
Thanks guys I think we are in line for intersting bike light construction now.
I have been riding with few fellows that have the Night Rider, and Light and Motion system. They are truely amazing lights.
I think I will be making something this year.
Hmmmm Christmas is soon... To me, love me, just what I really wanted. |
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| Variac |
The HID lights are very, very, bright. These are for people that ride trails at night or lond didtance rides in the country. For many bike lights leds would be fine, but even lots of them can't compare w/ HID
I sent the info about this company to a very serious bilke rider I know and he actually knew of them, said he had bought one, and it failed quickly. I will find out more... |
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| SCD |
Hello LineSource:
I do not think it is a question of right or wrong. It is more a question of how much light intensity is available given the type of riding. I am riding through dense conifer forest on narrow trails that have a lot of obstacles at a fairly high rate of speed. It is critical to be able to see extremely well.
I have not seen a light system yet that can out perform the HID. I have a friend that is using an LED system and it just does not meet the task.
This state of the art stuff and boy does it perform. It is hjust really expensive.
thanks for the comments |
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| SCD |
Thanks for the info Variac
I am very keen to hear more about the failed system. |
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| jeremym |
I'm thinking of building some HID lights for trail riding as well. There is quite a bit of discussion here, but I haven't really gone through it yet:
http://www.bikeforums.net/forumdisplay.php?f=20
I remember seeing some talk of someone buying the bulb and balast for around $100 USD-the rest is just like a halogen system, except I believe you may want/need to add some sort of voltage regulation on the battery output. Seems to me like you could put one together for a lot less than they sell for. And you're right, those things are incredible. Everyone seemed to have a set at the last 24hr race I did, and they are pretty much like riding in daylight. They make my 15W halogen setup seem like a birthday candle in comparison. |
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| Chris8sirhC |
I did one of those 24 hour mtn bike races about 2 years ago. I got to use both led lights and HID lights. Its literally the difference between night and day. The led lights simply dont have anywhere near the output to be able to ride a trail at an effective speed.
As a side note: if your going to make one, make it helmet mounted. What happens when your going around a switchback with a handlebar mounted HID at night....:xeye: |
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| LineSource |
| From what I have read, LEDs last at least 200x longer than HID, are more energy efficient in mcd/watt, are more rugged and allow instant on/off. One 5 watt and two 3 or 5 watt white LEDs sound attractive to me. Reflectors and an aluminum heatsink seem the basic building blocks |
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| mzzj |
| quote: | Originally posted by LineSource
From what I have read, LEDs last at least 200x longer than HID, are more energy efficient in mcd/watt, are more rugged and allow instant on/off. One 5 watt and two 3 or 5 watt white LEDs sound attractive to me. Reflectors and an aluminum heatsink seem the basic building blocks |
Many of previous posters are comparing 2-10 years old led technology to HID. 3 Watt or 5 Watt luxeons are in somewhat different league. HID-lamps yield 20-90lumens/watt and 5w luxeons about 25lumens/watt. Hopefully soon coming CREE chips 60lumens/watt.
edit: Maybe best side of leds is ease of use compared to HID in DIY projects, no need for 15kV starting pulses etc. And Li-Poly for batteries as they are more forgivin than Li-ion. |
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| AdamH |
OK, bit late on the task here but it may help someone....
I've just ditched the old halogen lights on the front of my car for some HID ones. Fortunately they are actually made for my car so all I had to do was wait until someone had some up for grabs on eBay. I managed to buy a set for 30 pounds (stirling) which for what they are is very little! It's like daylight in front of my car now, and the fog just isn't there (although it is here in abundance in england at the moment)!
Anyway, that all aside, my thought is this: These lights have their own HV transformer which sits in the back of the light cluster under the bonnet. It's obviously 12V being automotive, and from what i can gather doesn't actually draw all that much current either, (they'll run happily through a 3A fuse) so if you were to grab yourself one from eBay on the cheap and do exactly what us DIYers are all good at and run it off one a small 12V supply, maybe even charged by one of those little wheel servos you used to see on the back wheels of old bikes powering the lights. Job done.... that's my theory, eBay is your source for cheap High Intensity Discharge bulb assemblies and the right transformer for it the rest is childs play and a bit of reflectorship!
Just one more thing, don't point them in anyone's eyes eh cos the f'n sting like hell, these are REALLY bright!
Best of luck let me know if you do it. |
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| Variac |
The little wheel dynamos only put out like 5 watts and even they slow down the bike perceptibly.
LAtest word from my friend is that the bulb is fine, it is the batteries that went bad in 10 minutes. I have written back and quizzed him as to whether he tried the unit with different batteries and did it work OK? Trying to see if the ballast is OK.
He isn't very technical and IS very busy...
IF the bulb and ballast are fine, then it seems we might want to do a group buy directly from the bulb/ballast maker. That would be a lot cheaper and then the reliabilitty is up to the individual maker.... |
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| bentheboatman |
I'll be in on the bulk buy.
So far my this is what I've come up with:
http://www.batteryspace.com
14.8 V 5500mAh Polymer Li-Ion Battery w/leather bag $99.95
Universal Smart Charger $24.95
Welch Allyn 13W MR11 HID Bulb for replacement of Trailtech HID Light $75.95 -I don't know if this is the same as the M10P002-1
Using the 14.8V power pack, the nearest ballast is the 14.1-14.5V
Probably there will need to be some kind of voltage limiter too - but I don't realy understand how they work yet - here is a good link for anyone who is more electronically minded:
http://www.national.com/appinfo/power/files/f4.pdf
http://www.walamp.com
The Ballast - 14.1- 14.5V
Welch Allyn PN: B10N003 $79.00
The Bulb - 13 Degree wide Beam
Welch Allyn PN: M10P002-1 Parabolic Lamp $126.00
We can set up the bulk sell using Ebay. We need a wealthy volunteer first, to make the bulk buy...& I would volunteer myself but I'm currently skint!
Regards
Ben |
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| Variac |
Where did you get your prices on the ballast and the bulb?
BatterySpace seems to have and entire setup, helet mount, for $230
I think the ballast is mounted in the same pod the light is in?
Anyway my friend with the BatterySpace light just offered it to me to look over and try to fix.... I'll have a lot to report if that happens soon.... |
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| bentheboatman |
I got the ballast price from Welch Allyn official site.
The Bulb and ballast prices are fixxed on orders bellow a quantity of 47. Also there is a minimum order value of $100.
I believe the bulb is the same as the one on the Batteryspace website - so it is cheaper there. But batteryspace don't sell the ballast separately.
The battery that I have listed is a realy good low weight polymer Li-Ion battery - normally a HID light set up with Polymer Li-Ion battery is $500 or more.
Maybe you are right in that it is cheaper to buy the whole unit at battery space. |
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| rcavictim |
I checked out one of those sites and saw no bicycle headlights. What I saw were helmet lights with person carried batteries. Those could just as well be called skateboard lights, sexual adventure lights (if used in the bedroom.:D :att'n: ), or walking headlights.
I always thought bicycle headlights employed a generator mounted on the vehicle to power the lamp. Don't they do that anymore?
If these compact, low wattage arc lamps with ballasts are strictly battery powered why aren't they showing up as flashlights/lanterns? It is common to see much more power hungry 55 and 100 watt halogen bulbs in such portable lamps.
:att'n: Caution when using any form of arc lamp in bed as to avoid risk of fire! |
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| Variac |
A generator won't put out the power for these. There have always been both generator lights and battery lights. At least these batteries are rechargeble.
Why aren't they showing up as lanterns?
Well, how many people are going to pay $400 for a lantern?
Bike riders are well known to be willing to spend lots of money on gizmos, and they are motivated because the consequences of bad lighting can be severe injury!
I do believe I saw a handlebar mounted light at battery space...
http://www.batteryspace.com/index.a...TS&Category=738
Look to the lower left... |
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| Variac |
Update from my friend that bought the light. The Welch Allyn bulb and ballast are fine, it is the battery pack that gave out he says. Said that he had it tested locally. but hasn't sent it back yet. Ironic in that Batteryspace's contribution is the batteries.
He said he has been too busy to send it back, so we don't know what kind of service Batteryspace would offer.
So, I don't think it's fair to judge Battery Space too harshly- bad things happen and we don't know- they maybe they are incredibly responsive to problems...but one should be careful... |
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| AndrewT |
Hi,
bike power generation is available from axle mounted alternators.
When switched off they are very efficient (no drag).
Similarly when switched on, the efficiency is much better than the old fashioned tyre rubbing dynamo.
They would allow on road recharging and supplement the batteries when in use, extending the effective battery life considerably.
It is possible that on board recharging may remove the need to charge the batteries away from the bike. |
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| bremen nacht |
www.solidlights.co.uk use Luxeon LEDs (as mentioned by Linesource), Lithium Ion cells and some very nice PIC-based circuitry.
I used their 10W bar-mounted light alongside a 3W helmet light at a couple of 24 hour mtb events last year, and the combination was definitely up there with HID for brightness. And much lighter, cheaper and more reliable.
Their dynamo version is surprisingly good at wringing the last drop of energy out of a very limited source.
For DIY: use some sort of pulse DC-DC controller. Running them at less than peak current (eg from a series resistor) seriously reduces their efficiency.
Nothing to do with audio - for the tenuous connection, let me fact you up: the father of the guy behind Solidlights was the chief engineer at Neve for their original digital audio mixer design. |
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| Eva |
Have you all considered Compact Fluorescent Lamps?
Their light output per watt is similar or better to those of HID lamps, but the price is almost 50 times lower. For example, I got two 11W CFL lamps rated at 900 lumen each for just $5. The only big drawback is size, as these lamps are 20cm long and require some kind of custom reflector, but they costed almost nothing (efficiency, cheapness and size are mutually exclusive factors, as always).
One of my projects is a 12V powered electronic ballast with dimming for these lamps. In my current prototype, adjusting the light output allows to reduce the current drawn from 1A at maximum to 0.3A at minimum in order to allow to increase battery life at the expense of lower light output (lamp filaments end up using most of the power at the lowest light output levels, though). |
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| Variac |
That has crossed my mind, but you have done something- which is a lot more virtuous.
I would like to hear more about the fluorescents as an option.
I suppose a very sophisticated reflector could be made from a sheet of silvered mylar folded into a parabola in one direction. |
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| purplepeople |
Reflectors aren't that sophisticated. This type of handheld was available long before many of them were converted to UV for security use, counterfeit checking, etc.
:)ensen |
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| Variac |
that's a good example. The problem is mostly size, but that one looks pretty good.
My point was that we could easily make a better reflector than most and benefit - your picture reinforces my statement!!:D
here is a candidate that might be more sophisticated (to rip into parts?)
It is a coldCathode model..
http://www.batteries.com/productpro...sp?appid=315294 |
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| powerbecker |
snip:
...The problem is mostly size....
...only!:xeye:
transfer this to cars with about 60W : will look interesting with two 1,2m neontubes:D
Regards
Heinz! |
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| Variac |
Eva,
I think for bicycles the popular battery configuration is four cells, which is about 6 volts.
Do they make around a 6 watt 10 cm model light tube? 6 watts is a power consumption that would allow reasonable battery weight and enough hours for long rides...
I think that one dimming setting of about half power is probably enough...
This is from interviewing my riding friends...
I'm interested in more info |
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| Eva |
I'm working on it from time to time. There are smaller CFL rated at less power, but I think that they are less efficient. Also, small low-power lamps may be easily taken from those fluorescent light-bulbs that include a built-in ballast, I suppose you know them, they are available in different shapes and sizes.
Currently, my circuit uses a SG3525 driving two MOSFETs that switch the push-pull primaries of a tiny transformer, which produces 120V AC and has two additional 12V AC windings. Operating frequency varies between 50Khz and 125Khz. The 120V AC output feeds a 75Khz LC resonator that ignites the lamp and then works as a ballast allowing for dimming by changing the operating frequency. The two 12V AC windings provide variable power to the filaments depending on the frequency by means of a capacitor in series with each one (lower dimming levels require increasing filament power, while full intensity requires little or no filament heating).
The main drawback of the current prototype is that it's not automatic, it has a frequency potentiometer that has to be adjusted to approx. 75Khz for starting the lamp, then you have to wait a minute for the lamp to get warm and then it can be dimmed. I will make it automatic, though.
A 6V version may be also possible by employing logic gate MOSFETs and some tricky start-up bootstrap circuit. |
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| powerbecker |
Eva,
If You try to google "royer oscillator" You will find a lot like this attachment.
Regards
Heinz! |
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| Variac |
I think mainly because you can get much brighter ones than those you listed. It is a lot easier to work with one LED and one reflector, etc. than 5. Cateye used to make a light with a cluster of 5 which was prettty bulky and heavy, but now are using one much more powerful one. The big ones I mentioned , like the are now up to about 3 watts
BUT your place is a good resource, they also sell the big ones: http://www.besthongkong.com/newsdes...?newsdesk_id=47
http://www.besthongkong.com/product...products_id=171
I need to check prices, the places I mentioned also sell lenses and reflectors that fit the star LCD's.
Also, it is possible that the HID lamps and even the fluorescent lamps are actually more efficient than LCD's . People assume that LCD's are the most efficient, and I'm not sure its true... |
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| Eva |
| quote: | Originally posted by powerbecker
Eva,
If You try to google "royer oscillator" You will find a lot like this attachment.
Regards
Heinz! |
I don't know where you got that circuit, but it won't work at all for normal low-cost compact fluorescent lamps in the power range that we are discussing.
Note that a normal 11W compact fluorescent lamp like mine requires proper filament heating and 400V for starting, and 100V 100mA for operation. There is no way in which such a circuit could provide 100mA to the lamp as it has a 562 ohm resistor and a 50K pot in series with it that would burn instantaneously! Also, there is no way in which two TO-92 transistors rated at 2A max could provide 11W lamp power with input voltages as low as 6V.
Actually, as it has a 33pF 3KV capacitor in series with the lamp, it seems like a low power neon tube dimmer (5W or so, like the ones used in computer modding). |
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| powerbecker |
| quote: | Originally posted by Eva
"I don't know where you got that circuit, "
Itīs from AN 45 LinearTechnology (1991), You can load it there.
"but it won't work at all for normal low-cost compact fluorescent lamps in the power range that we are discussing."
Of course itīs not a recipe, interesting is the topology.
It deliver very easy high hf-voltages. For instance I build with this
topology a source for hf-surgery : 500kHz, low distorsion sinus, 150 W @ 93% effectivity.
The actual schema is for 5W lamps, worked @ 60kHz and deliver 1400Vpp.
"Note that a normal 11W compact fluorescent lamp like mine requires proper filament heating and 400V for starting, and 100V 100mA for operation. There is no way in which such a circuit could provide 100mA to the lamp as it has a 562 ohm resistor and a 50K pot in series with it that would burn instantaneously! Also, there is no way in which two TO-92 transistors rated at 2A max could provide 11W lamp power with input voltages as low as 6V."
If You use "real" HIGH Voltage ccs You donīt neat the heaters!!
"Actually, as it has a 33pF 3KV capacitor in series with the lamp, it seems like a low power neon tube dimmer (5W or so, like the ones used in computer modding). |
Yes, behind many (big) screens there are some of this lamps.
You can use also a little bit other schema to came with high effectivity to high voltages : Output current from a power-comparator drives via transformer a L-C series connection, feed back the input current with a current transformer to the comparator to get nearly zero switching losses.
The biggest oscillator I had to build with this deliver 16kW @ 100kHz to power a 4MW LC series connection (8000Vrms/500Arms), witch produce a strong high frequency magnetic field.
Regards
Heinz! |
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| Eva |
| quote: | | If You use "real" HIGH Voltage ccs You donīt neat the heaters!! |
There is no way in which you could make a conventional fluorescent lamp light at lower than maximum intensities without heating the filaments. It will just stop lighting as soon as you try to reduce the duty cycle. Also, since conventional fluorescent lamps have a strong negative impedance, they can't be dimmed by trying to reduce the input current to the transformer through a buck regulator (the voltage will increase as current is reduced, thus keeping power constant), dimming must be achieved by duty cycle control. Furthermore, skipping filament heating for conventional lamps is said to reduce its useful life by an order of magnitude.
This circuit is much better suited for conventional fluorescent lamps:
In that circuit, dimming by duty cycle control is achieved by increasing the drive frequency. That's not due to the inductor, but because the capacitor in parallel with the lamp imposes a crossover time on each transition, during which the lamp conducts little or no current due to a lack of voltage (filament heating is required to keep the gas ionized during that period, otherwise the lamp won't conduct again in the next cycle). As the frequency is increased, the relationship between the time the lamp is conducting and the time the lamp is not conducting (crossover period) decreases, thus decreasing light output.
Also, this circuit has a very nice feature: The power applied to the lamp decreases linearly with increasing phase lag of the inductor current with respect to the drive voltage. This means that precise dimming is easily achievable for different lamps, different temperatures and different LC values just by adjusting drive frequency to get a fixed phase lag, thus estabilishing a phase-locked loop. The current phase lag is quite easy to detect by sensing the voltage drop across one of the switching MOSFETs during its conducting period and finding the zero-current crossing point (where Vds is exactly 0).
Anyway, if you just drive the MOSFETs straight from a SG3525 at a constant frequency close to the resonance of the LC network, the lamp will light nicely.
Even the following circuit produces excellent results despite its simplicity, altough filament current ends up being somewhat higher than required and it's not easy to reduce it.
And the best of all, net light output from a fluorescent lamp is similar or better than from an HID lamp at similar power levels (altough light is much more concentrated in the latter case). |
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| jleaman |
id like to post that besthongkong.com was a rip off i got screwed over totally i waited 4 months and have not recieved a single product from them. :(
Im now using > http://www.lsdiodes.com
Scott's idea here is to use the same battery pack as what comes with his bike lighting system as it is but get better / more lighting and a longer lasting light run time. I think super bright white led's with a high cid will be the trick. |
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| powerbecker |
"There is no way in which you could make a conventional fluorescent lamp light at lower than maximum intensities without heating the filaments."
Well, Eva, I have no practically experience about that.
On the other way, with lamps described eg in AN45 it works.
In my limited understanding the physical process in all this gas-discharging lamps is the same. Of course the characteristics depends from pressure and kind of fillings, dimensions and temperature. And always helps heated electrodes to work or start with less voltage and also all represent after ignition a negative resistor.
"It will just stop lighting as soon as you try to reduce the duty cycle. Also, since conventional fluorescent lamps have a strong negative impedance, they can't be dimmed by trying to reduce the input current to the transformer through a buck regulator"
This seems clear for me, because this is not a real current source which will enforce the current, one can this also imagine as a cycle by cycle ignition.
I think it will be a interresting experiment with Your circuit to feed them from a (DC) currentsource, implied all parts are useful for a higher outputvoltage.
May be I get the time to try it in my company with a constant current poweramp which can deliver 800Vss DC to 100kHz.
But I had to wind a 1:2or3 step-up transformer and my free time is limited.
If You do some experiments care to Your probes, at higher frequencies they break down at much less voltages as, say they withstand @ 10kHz and less. This way once I killed a 1000:1 HV-probe!
Regards
Heinz |
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| SCD |
Thanks for chiming in Jason;
I have been reading this discussion with interest. I am not familiar with the florescent lighting as a portable helmet mounted system.
I have riden with folks that have the LED system. That fellow has had lots of trouble with his battery pack and I think the lights are not quite brite enough for me.
Other fellows have the HID systems that are quite incredible. One made by Niteride the other by Light and Motion. Both systems perform very well. The cost of these is way up there in the $700.00Cdn range. Well beyond my reach.
The HID sysytems are what inspired me to start this discussion. I am hoping that other riders will be interesed in developing / designing a DIY system that might bring the cost down a bit.
Now that daylight savings is here and daylength is increasing so fast right now the preasure is off a bit for this year. That allows lots of time for discussion and design.
Keep the ideas and thoughts coming. This is a ways off of audio but it is still DIY
Thanks for the help |
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| powerbecker |
Hello Eva and all,
I had to do my work, but this things seems to put me off:
By Zetex I found a lot of interesting information and links about ccfl and leds: http://www.zetex.com/
For ccfl it is very usefull to download AN65: 124 pages interesting stuff from
http://www.linear.com/designtools/app_notes/index.jsp
A part at the end I cut out to show it here. There they say, that the hcfl-lamps (hot cathode) work equal with their ccfl-circuits...without using the heater!
Regards
Heinz |
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| Variac |
My stupid friend has convinced me to try some brevets this year. The first official one in 300km. Even with summer light we will have some darkness!!!
He has the Princeton Tec 3 watt LED. It isn't quite bright enough, but I think that means a 5 watt might be.
OR:
A wide angle 3w on the bars paired with a 3w spot on my helmet. That would consume 6 watts which is low enough for decent battery life.
I'll report back!
Jason, Useful to know that that LED place you linked us to isn't reliable. Make sure to tell us what happens!
Mark |
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| jleaman |
| quote: | Originally posted by Variac
Jason, Useful to know that that LED place you linked us to isn't reliable. Make sure to tell us what happens!
Mark |
I'll keep us all posted on the new place. i was told from another member on here that the new company that i just put up for share's is really good. ii just did my order so far so good :) 3$ for shipping to canada WICKED deal the other company charged me 12$ us :( |
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| Eva |
powerbecker:
It's what I said previously. The lamps discussed in that paper have nothing to do with conventional fluorescent lamps when it comes to drive them. If you look at the diagrams, their circuit is used to drive tiny tubes drawing 5mA with working voltages as high as 1KV (neon like). Conventional fluorescent lamps draw much more current (100mA the smallest ones, even 6W) and use much lower working voltages (around 100V).
Also, I suppose that you have seen that the two automotive medium-size lighting systems shown were CCFL but required external heaters for proper starting in cold ambient conditions, causing 30% losses due to capacitive shunting. Hot catode fluorescent lamps doesn't sufer from any of these issues because they have built-in heating (note that the voltage is 10 times lower and the current is 10 times higher so shunting capacitive losses are negligible).
Anyway, somebody trying to build a DIY fluorescent system is going to have a trouble finding CCFL lamps and getting them at a reasonable price, so we should forget about these. |
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| suzyj |
I can verify (having used that light for a couple of years including two 400km brevets and a 600km brevet) that the light linked to is a good-un.
If I were building another today, I'd use the new Cree XR-E LED, which manages some 70lm/watt.
Cheers,
Suzy (slightly surprised at finding a cycling thread on DIYAudio - where's the framebuilding thread?) |
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| bremen nacht |
| quote: | Originally posted by Variac
YOW! I was this close to ordering the 5 watt luxeon!!
But this is amazing:
http://www.cree.com/press/press_det...i=1160427137863
State o' the art!!!!
Now I gotta think again.....:rolleyes:
There are more than few bikers lurking in high places around here... |
Well, low places...hello!
Are the Cree LEDs available yet?
Problem with chip LEDs is heatsinking them. I haven't found anyone that does alumin(i)um backed pcb in proto quantities, would be grateful for any leads.
I use a Luxeon 3W, not even at full power, for my unlit country-lane commute and it's fine. Most drivers dip their lights so I know they've seen me, and even if they don't the Luxeon is so bright that I'm not blinded after they pass.
These guys do really good prices on LEDs and lenses:
www.dotlight.de |
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| AndrewT |
Hi,| quote: | | I haven't found anyone that does alumin(i)um backed pcb |
why would you need aluminium for a heat sink, when copper is so much better. Just as copper is better at carrying current, so you only use aluminium when some other reason (characteristic/property) overides the better material's properties. |
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| bremen nacht |
| quote: | Originally posted by AndrewT
Hi, why would you need aluminium for a heat sink, when copper is so much better. Just as copper is better at carrying current, so you only use aluminium when some other reason (characteristic/property) overides the better material's properties. |
I was referring to aluminium backed pcb, which is a sandwich of copper, very thin FR4 then 1 or 2mm aluminium. I don't know whether anyone makes anything similar with copper.
http://www.clarydon.com/services/metal_backed_pcb.html
Luxeon use it for their mounted LEDs. |
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| djQUAN |
I have use a high power LED (a cheaper taiwan copy of a luxeon) and it is blindingly bright.
I'm using a Li-ION batt pack scavenged from a broken laptop and AN-003 from ESP (raised the current to 320mA) and it works quite well considering the price. :)
right now, I'm bench testing the Li-ion charger that I made since searching the net leads to charge controllers that always use a dedicated IC so I made one that uses an op amp, some transistors, passives and a 16V laptop charger. |
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| suzyj |
| quote: | Originally posted by bremen nacht
Problem with chip LEDs is heatsinking them. I haven't found anyone that does alumin(i)um backed pcb in proto quantities, would be grateful for any leads.
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For Diy stuff, I'd just machine a copper block, bung some solder paste on it, and sweat the LED onto that. As long as the block has cutouts so that it doesn't contact the anode and cathode, it'll work very well. Thermal conductivity would be better than with an aluminium backed PCB too.
Of course, for quantity stuff, the PCB is the way to go, as it'll be lots cheaper.
Cheers,
Suzy |
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| AndrewT |
But copper is better for conducting away the heat.
Cppoer's main disadvantage is weight and cost. But as a bonded PCB plate I suspect neither of these disadvantages are significant. |
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| suzyj |
I used the 700mA one with my Luxeon-III. My reasoning was that there wasn't a particularly big increase in lumens from 700 to 1000mA, and I wanted the light for all-night brevets, so wanted to keep the power consumption reasonable.
Everything I've read about the Cree LEDs imply that they max out at around 700mA, so I'd go for the same module for a Cree LED too.
Cheers,
Suzy |
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| Variac |
Yup, the Cree efficiency is what's so appealing. I have now done a 200k and 300k brevet and various double centuries. For the 300k or double century (200mi.) we certainly need lights for a few hours. I can't say that any further would be appealing, but who would have thought that I'd be doing the distances I'm doing now? -not me!
I wasn't too thrilled about the idea of riding for hours in the night, but it turns out to be rather peaceful and fun -even with some car traffic. I did have even more fun when I was with some other riders that had better lighting, so a decent light directly equates to More Fun!
Even though we think highly of ourselves here in northern California, we are forced to admit that our roads are often in poor condition, and the nagging thought that your wheel is about to disappear into a pothole takes away a bit of the joy ;)
variac |
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| panomaniac |
| quote: | Originally posted by Variac
it turns out to be rather peaceful and fun -even with some car traffic. |
Sure is! I ride home every night from work - 'round about midnight. Lovely. No wind, no hot sun, very little traffic. Have ridden all over the island at night, what fun!
I bought a bunch of 10mm white LEDS to make a light from.. Never did. Seems like you guys have a good thing going here with the 3W and 5W leds. Wow! Was going to make a solar charger for my light. Maybe I will, someday. |
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| bremen nacht |
| quote: | Originally posted by AndrewT
But copper is better for conducting away the heat.
Cppoer's main disadvantage is weight and cost. But as a bonded PCB plate I suspect neither of these disadvantages are significant. |
Probably because there's the thermal resistance of a layer of FR4 between the copper and the base material, so the reduced resistance of copper is not significant.
I don't know. I've never seen Cu/FR4/heavyCu, but Cu/FR4/Al is commonly used for taking the heat out of RF circuitry. |
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| djQUAN |
I got four Luxeon V's off ebay for $20 and since they're only the bare bulbs, I will be needing the aluminum core PCB.
since heat reduces the life of the LED, I was thinking of something better than that, what about using something like the metal tab of a TO-220 transistor (only the metal tab, get a copper plate to a similar size and shape) and solder the LED heatslug on it. since the back must be electrically insulated, mica and grease would do nicely here.
soldering may not be a problem since I have soldered IC's with heatslugs in the past and they worked just fine. I just don't know how much the LED's will stand the heat.
any comments? |
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| Variac |
That seems like a great price!
I am also plannning to add a small square of aluminum or copper to a bulb. Most components can stand soldering temp for a certain amount of time. MAybe the specsheet states this. So maybe you have to solder fast with a massive soldering gun or such and then quickly place it on a thick and large piece of metal to cool it?
This is another possible way, Arctic Silver Thermal Epoxy:
http://www.coolerguys.com/840556003014.html |
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| djQUAN |
I would have gone with the thermal adhesive but availability is an issue besides, soldering is still better thermally ( I think! ). I can't try it since the LED's haven't arrived yet so I'll have to wait.
I got the LED's from here
and they are removed from unused stuff from what I can tell. although the bad thing is, the next day later I found out someone is selling new Luxeon K2 whites at around $5. damn. oh well. the good thing is, I can only get Al core PCB's for luxeon I's (luxeon V's have the same footprint) so I won't be able to use AL core PCB's on the K2's anyway. |
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| djQUAN |
incase others may be interested........
Luxeon K2's
I saw other colors available too............ |
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| goodbyegti |
I started building some HID lights, check out the progress so far...
Take 1 H4H 35W HID lamp (from a car)
Take 1 mains voltage halogen reflector lamp and carefully remove the front glass (i tried with 2 diffferent bulbs to get it off without breaking the glass with no luck)
Saw the end of the lamp using a tungsten carbide blade and some tape to keep your fingers safe.
I finished it off on a grinder wearing all the proper protection stuff (didn't fancy glass in my eye)
I used a bit of copper pipe to mount the reflector central around the lamp and some exhaust cement to hold it inplace
Testing! In real life all the trees got lit up in the background, it was very bright!
Shining it at the floor, nice round projector (i think 20 degree spot).
I'd say in real life life it's significantly brighter, the camera hasn't picked up much of the surrounding which were lit up pretty well.
Next up is the battery, i want about 3 hours run time so it's going to be around 120WH. I was thinking of using a li-ion laptop battery as it work's out fairly cheap. I just need to devise a way of charging it carefully - i think this will be the hard bit. I might use a PIC chip or something.
As for the casing i thought about moulding some CF, or perhaps fibreglass if i'm feeling cheap :)
The plan is to blow away my mates 10W HID which cost him Ģ300! |
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| Variac |
| Awesome! What are you using for the high voltage power supply? |
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| SCD |
Let me be the first to say wow!
I love it. Yo may be on to something here.
Things to watch for:
Temperature, temperature temperature. It is going to get hot,real hot.do not get things too conjected it will need room to breathe.
Mud and **** on the reflector, you will need a method of keeping it clean some how.
Replacement bulb do you have to completely remake the lamp when the bulb burns out? Is there a way you can make it so you can work through a few prototypes.
Mounting bracket, I have used a handle bar mount from a cheap Cateye when making other systems. A helmet mount would be really nice once you get the bugs worked out of your prototype.
Power you will need at least a 5 or 6 amp hour battery to get any reasonable amount of burn time from a 35 watt bulb. Lead acid will be cheap but very bulky. NiCad may be a better way to go. Li-ion will also be expensive. I recommend Lead acid for the prototype and if it works out go for a lighter better system once you have things a bit more refined.
Good for you and good lucky |
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| goodbyegti |
Variac: The HT supply is simply a denso HID ballast pulled from a Lexus. As it's built for a car it runs off a good range of voltages (about 10.8- to 14.4v) and also features hot ignition :)
It seems fairly efficent as well, doesn't get that warm so not much energy wasted. It's also pretty small, although not as small as typical ballasts like on the the cateye stadium...
SCD: Thanks for the comments!
You're right, there is no way i can run it like this on a ride, it needs a proper housing. I have an old cateye stadium kit i can tear up, and with a bit of modification i should be able to fit the lamp in the housing. That solves the mounting issue as well.
The lamp has a lifetime of about 3000 hours, and i imagine a typical battery will only last about 300 cycles so it really should last the lifetime of the system. Having said that i think it wouldn't have been much more difficult to make the lamp replaceable...
Yeah, the battery will need to be fairly big. I have a whole load of lithium cells but i'd need to parallelize them massively to get a good capacity. Also being lithium you need sophisticated control circuitry to avoid them blowing up and for a lot of cells this is tricky.
I like the look of large laptop batteries like this one:
http://cgi.ebay.co.uk/8900mAh-DELL-...1QQcmdZViewItem
This should easily get around 3 hours run time and once i figure out how to charge it ,all the safety features are built into the battery.
Yes, lead acid is cheap but heavy! The batteries also degrade rapidly if you constantly discharge them fully. I think for the small amount extra i'll pay for li-ion it's worth it over Ni-MH as for a battery this size saving weight is very important!
As for temperature issues I've use the lamp for about 2 hours non-stop and whilst it does get pretty warm it's stable and doesn't melt any of the plastic plumping pipes i've got attached to it. I expect when it's fully enclosed this may become more of a problem, but hopefully it won't be a major issue as the cateye housing is built from metal.
The annoying thing is i don't have time to work on it until the summer, but hopefully this might give people some ideas :)
PS. I like these LED lights you guys are talking about, i think for most puposes LED lights are the future.. |
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