Suffolkandgood
New Member
That is absolutely amazing. I want some!
Datatek
Well-Known Member
decided it was time to change my roof lights. i have 4 bosch 100w floodlights on my roof at them moment and felt that they used a lot of current and were bulky for the light they produced.
so knocked up a prototype light to try out with the thought of making 2 more if it was good because i thought it would look weid with just one spot on the front..
bit of 4" billet
mounted up with lens, reflector, current limiter and 100w cree xpg chip
Had high expectations for it, data sheet on the chip is 13000 lumins.
All i can say is that im staggered how bright it is!!!!
its a spot and flood all in one! its definitely 10x brighter than all my original roof lights and headlights on full at once. once its on i cant even tell when i put the roof lights on or flash my full beams.
Obviously it will be used for off road only and im in the process of making a PWM circuit so a will draw less current / heat up less but will also have the feature of dimming it.....
You could go into business with those
discomark10
Well-Known Member
Have you read the spec sheet? Speaking to the old man today, he has made a set-up with a 50w and I told him about your one, he commented about the running temp and mentioned that the LED life is reduced if the junction temp is above 65c.
Have you thought about maybe a fan setup?
Have you thought about maybe a fan setup?
Datatek
Well-Known Member
If he builds a PWM power supply as he proposes with temperature feedback, no additional cooling will be needed.
discomark10
Well-Known Member
It would have to either limit the current to allow a lower operating temp or cut it off, only reason I mention cooling is so it will keep at optimum operating current.
Might also be with increasing the surface area so it can cool faster, it doesn't matter how big a mass you have as a sink, it still needs to transfer the heat to the air.
Might also be with increasing the surface area so it can cool faster, it doesn't matter how big a mass you have as a sink, it still needs to transfer the heat to the air.
Datatek
Well-Known Member
PWM does not affect current, it switches the LED on and off faster then the eye can see, temperature is controlled by altering the duty cycle
discomark10
Well-Known Member
Pulse Width Modulation with temp feedback would be effective @ avoiding over temperature, however the light output will effectively reduce in proportion to the duty cycle, just like a dimmer switch in your house.
As a result it will start at full brightness then reduce as the temperature reaches feedback equilibrium.
As a result it will start at full brightness then reduce as the temperature reaches feedback equilibrium.
bankz5152
Well-Known Member
Not sure if you mentioned it but round about how much did it cost your for the LEDs? And the total build?
Also found em on eBay if anyones interested.
http://www.ebay.com/itm/230831129271?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
They do em in 50w too.
Also found em on eBay if anyones interested.
http://www.ebay.com/itm/230831129271?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
They do em in 50w too.
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Dr_evil
Banned
Did you get the lenses from the same place ?
Had a thought cooling wise too, would an oil heat sink like you get on arc welders work using a very small electric pump seeing as you're running at 75 at 5* outside so shouldn't need huge cooling ?
I.e. a tube of ally tig welded round the exterior and filled with oil leading to a small cooler to dissipate the heat ?
Would solve the need for fancy electrics to pulse the light
Had a thought cooling wise too, would an oil heat sink like you get on arc welders work using a very small electric pump seeing as you're running at 75 at 5* outside so shouldn't need huge cooling ?
I.e. a tube of ally tig welded round the exterior and filled with oil leading to a small cooler to dissipate the heat ?
Would solve the need for fancy electrics to pulse the light
Dr_evil
Banned
I'm gonna get some billet off ebay and have a play about I think
Them daylighters are about as good as you'll get from halogens I've still got a pair of them myself as well as the HID pair, but the LED's will be more compact and I have a sneaky idea.
Thinking blank off the front wings on my series, mount a pair of low output LED lights within them so they're nice and discreet then a pair of the spot light powered ones with cooling system within the new winch bumper I'm making it.
Them daylighters are about as good as you'll get from halogens
I've still got a pair of them myself as well as the HID pair, but the LED's will be more compact and I have a sneaky idea.Thinking blank off the front wings on my series, mount a pair of low output LED lights within them so they're nice and discreet then a pair of the spot light powered ones with cooling system within the new winch bumper I'm making it.
mikeyt
Active Member
Ive learned quite a lot since first making one of these... avoid cheap ebay led's when i first ordered some for testing i bought cheap jobbies and have had average results...some of them have parts of the leds not working from new (ill post pics tomorrow camera at workshop), had a lot of heat generated for not very much output (inefficient), and ones where segments have died under normal operating currents and temperatures...
i have made several of these lights now and now use these leds 100W Cree XPG LED Emitter 100 Watts White Light 7000K 13000lm [BY-CR100W] - US$59.99 : Topledlight
with the same heatsink i have nearly halved the operating temperature curve over time under the same operating conditions with a increased output and that's before PWM.
Another part i have found difficult is being able to produce a stable current at 36v with a lower than 13v input. i have now designed a new circuit with PWM and temperature controlled current limiting built in and its going through testing before i have the printed circuit board made, now having problems finding sutible 4 core cable to supply both power with smaller cables for the thermocouple (to keep the cable nice and small)
Been having meetings with Clive (pressbrake) on the manufacture of the aluminum body's once i get them on cad.
Cad file will do then if complicated ie milling I'll use delcam though for simple turning the machine intuitive programming is fine.
Dr_evil
Banned
ahhh right, the beaver CNC we have is manual input on the keypad but the other one is an upload from computer and the CNC lathe I've not played with yet
will hand make anyway when I attempt one of these
mikeyt
Active Member
a winding system wont work, for a few reasons the main ones a transformer needs ac, would have to be quite big if you did convert to ac then back to dc to supply 3.5 amps. current limiting, stability over operating voltages 12v ign off up to 14.5 running etc etc....
few pics of cheap leds i bought when first fiddling taken through a shaded lens note the amount of segments lit these were all new and ran on a heatsink from a current limited power supply...
These were all bought from different sellers and were different specs.all the segments were lit but a drastically different light levels the ones that dont actually look lit were glowing, the camera for some reason has made some look purple but they were all white
