200w led driver pot replacments/resistors

[bionicdan]

I am currently half way through building a 200w max led lamp for my bike. I bought a pwm dimmer for led's but they all run 1amp max instead of the 8amp they often promise.

So I have room for two 100w chips in my housing and have purchased a 10amp pwm motor driver with a potentiometer to vary the load. I want to connect this to my main beam/low beam handle bar switch unit to enable barely on (no one swearing at me or daytime runner) and 10.000 lumen setting at around 1.5amp per led for riding up my lanes at night. I have one 100w led running super cool at 1amp 30v pwm as my prototype on a cpu cooler right now.

I also need to stop 10amp getting to my 6amp max leds. In effect I need a 3 speed switch setting like some big motor controllers have. Maybe I can just run a resistor between the number 2 wiper pot to half the 5v feed and keep the pot as it is. I like having full range adjustment But 90 percent of the time its just full on or all the way down so people dont shout at me. On a side note it is nice that drivers now turn their lights off full beam for me when they never bothered before as I am just a lesser being on a bicycle.

So how can I limit the pot feed to make sure the load is around 5a max or how can I replace it with resistors of two magnitudes for high and low settings? Cheers if anyone can help or has done this on other devices. I have the driver ordered but wouldnt mind getting the extra parts in before it arrives in 3 weeks. Even then I might blow it up lol

The leds are around £11 on ebay each, the housing is around £11 and the drivers around £8-£5
controller
http://www.ebay.co.uk/itm/251204533026?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
lamp example
http://www.litecraftcommercial.co.uk/OUTDOOR-FLOODLIGHTS/pid8455/cid8/10w-LED-Outdoor-Security-Floodlight-with-PIR-in-Satin-Black.asp
100w led 45x45 big chips
http://www.ebay.co.uk/itm/High-Power-New-100W-Warm-White-LED-Saving-Lamp-for-floodlight-outdoor-Light-/251204554523?pt=US_Light_Bulbs&hash=item3a7cf54f1b

 

[amberwolf]

I want to connect this to my main beam/low beam handle bar switch unit to enable barely on (no one swearing at me or daytime runner) and 10.000 lumen setting at around 1.5amp per led for riding up my lanes at night.

looks nifty so far; what optics will you use to make a beam that goes only on the road and not up at people's eyes?

fwiw, the larger the sruface area of the light the easier it is to see you without being blinded, and the easier it is to reflexively judge how far away you are and how fast you aer going, so if you could point hte actual leds into a reflector to create the beam, with the reflector as large as is physiclally practical on the bike, it would make super bright lighint mch more tolerable to anyone facing you.

typically car and motorcycle headlights are roughly the area of a human hand with fingers together flatenned out, so thats one thing people unconciously learn to judge distance/speed at night by.

also, for daylight you could more easily use teh ful lbrightness mode, as it won't blind peole and they can better see it in daylight.

I also need to stop 10amp getting to my 6amp max leds. In effect I need a 3 speed switch setting like some big motor controllers have. Maybe I can just run a resistor between the number 2 wiper pot to half the 5v feed and keep the pot as it is. I like having full range adjustment But 90 percent of the time its just full on or all the way down so people dont shout at me. On a side note it is nice that drivers now turn their lights off full beam for me when they never bothered before as I am just a lesser being on a bicycle.

So how can I limit the pot feed to make sure the load is around 5a max or how can I replace it with resistors of two magnitudes for high and low settings? Cheers if anyone can help or has done this on other devices. I have the driver ordered but wouldnt mind getting the extra parts in before it arrives in 3 weeks. Even then I might blow it up lol

i guess it depends on the driver cirucit--if it has a brightness adjustment dimmer input, you just figure out what voltage into that (or resistance) creates the output current you want.

with a motor speed controller like the linked one you should be able to first just ensure its max voltage input suply doesn't exceed the leds' rating, so if it's fets fail (usually shorted) it can't blow your leds by voltage. then calculate current you'd have thru the led at max output of motor controller at that voltage. if it is too much, then you calculate what percent of throttle input would be the max output of controller the leds could handle. then limit the range of your input to that, down to zero.

can do with a voltage divider if it takes a voltage input for throttle, and can just tap off a voltage diviider for various brightness levels, using a multi-way siwtch like some 3speed switchs to get mulitple settings. use the common poleof switch to go to throttle in of conroller, and the switched contacts to go t each of the various taps of divider. some 3 sepeeds witchs use cnter position = open so that would be center-off whic hmeans youd only have lowbeam, off, and highbeam.

could wire up so that center-off position is wired to lowest votage tap, then medimubeam position shorts acoss one resistor in stakc above that tap, and highbeam position shorts across two of them, with one more still above that that prevents ever going highr than max current.


does that make sense?

 

[bionicdan]

Yes I think I am getting what your saying but it is late so will soak it up tomorrow hopefully cheers for that. Might be easier to visualise when its in my hand too

Right now it has a reflector housing and glass collimator? strapped to the front so as long as you are 30 degrees off to the side it deflects the worst of it. the security light fits perfectly between my forks! I actually only got sworn at when I used a 50w 8000k super cool white led with no optics. It was so white I couldnt see the pot holes or lumps as the contrast was rubbish (everything looked blue/grey) lol. Warm whites only for me now 3000k

I rarely have any trouble in the daytime as my bike is huge and suggested a low daytime running light as my heatsinks may not be up to full power all day. Also My motor pulls around 8amp cruising so I dont want to add another 3a. You absolutely cannot look at it straight on full in the day or even on low at night. Otherwise you see spots for a loong time

I ran the lamp on a constant current boost driver at 2.6amp for a few mins and it smelt hot lol.

I only run pwm driver over 9 life cells making 29.5v max so if something goes pop it will only be at min voltage anyway.

Maybe I can add some material to this case on the back or add some cooling holes for air as I never go out when its wet.

This really is big lumens for little money I think

*it looks like the trees are being lit by the spill but they arnt its purely bounceback off the wet grass. You can see by the picture that just standing slightly above it has resulted in none of the yellow led showing in the glass. This gives you an idea how well that glass keeps 90 percent of the light directed forwards not at victims on the side of the road

The driver I have right now sits on my cross bar in a pocket on the battery bag with the variable pot. I have also ryn it through a motorcycle control unit on the bars. Then I can cut it dead asap while my keygos t6 is on. Sometimes I realise I am blinding a pedestrian down the country roads and just need it off. I also use the three position indicator switches to control my three speed controller positions. I have some three speed throw switches around too that might come in handy

 

[amberwolf]

It was so white I couldnt see the pot holes or lumps as the contrast was rubbish (everything looked blue/grey)

if you put the light at a level less than halfway between your eieys and the road surface you can much moer easily contours of road or debris, the shadows cast are lots easier to tell what they are. the higher up the light is vs your eyes, the shorter teh shadows and the less able you are to see stuff like that. of course, the lower it is the shorter teh throw without blinding others down the road facing you, so....

You absolutely cannot look at it straight on full in the day or even on low at night. Otherwise you see spots for a loong time

anything that bright is too small a spot for the lumens...you should make a bigger reflector area and poing the led at the reflecor and not out at the world. then let the reflector/optics make a wide beam (not wide angle but actually a wideer beam) so that no one spot of it is too bright to look at straigtn on.

at the very least you should put a 'lid" in there to shade the half of the light that would be projected above the road level, like hid lights (shoudl) have.

otherwise you risk temporarily partly bilinding people so they can't see somethign else on the road and cuase them to hit it or run over it; even possibley cause pedestrians to walk off the sidewalk into road or other things/epople/etc on the sidewalk.

i've seen this happen with cars that have hid lights in place of their old halogens but no proper 'lid' in there to keep it from blinding people, only casting light on the road, and some motorcycles that have ultra brigth headlights up high (wher e most cars are lower to the ground) that laso have no 'lid' to shade the top half. i've sometimes been blindied by them myself, as pedestrian and as cyclist, and almost crashed into things as a result.

I ran the lamp on a constant current boost driver at 2.6amp for a few mins and it smelt hot lol.

sound s like you need much better airflow over that heatsink. if the heatsink is trapped isnide the box it can't d o it's job. it has to be outside teh box. or else you must pull lots of air thru the box to keep the fins cool so the heatsink can worlk.

or you could polish up and flatten a spot on the case itself, and bolt the led directly to the case.

a good test is to measue temperature of the led die (or as close as you can get on the face of the leds, maybe with one that you point at things to measure) with it running with heatsink/led not in the case, just held out in open still air as warm as you expect to ride in. if it still gets too hot like that, you probably have to have a fan puling air thru the fins. if it is fine like that then you may well e able to just bolt the eld to the main case without the heatisnk and use the case as teh ehatsink.

 

[bionicdan]

Yeah it doesnt help I have really high front forks and will put it as low as I can to the tire. The white led just made every lump and bump unrecognisable as it was all washed out colour wise and too glarish for my eyes with no type of lens.

I have had an idea 30 seconds after waking this morning lol. I am totally happy with the beam spread as it is for off road and the lanes when no one is coming. So I may mount that one to the right side (as im sat on the bike) of the housing body directly. Run it via the 10a pwm set and locked at the level it can handle without overheating the led. Then via my main beam rocker switch so I can flick it on and off like I do already when I cant get to my dimmer quickly.

Then I might frost up/etch spray the left portion of the glass and mount my white 50w led so it only gives off a glow not a glare. This can run off my 1a pwm variable circuit as a daytime runner and large night time marker while my main beam is dormant. Maybe I will remove some of the black coating but its really on there, like a copper laminate.

I either ride in well lit towns and just need a marker for others to see, or unlit lanes and need a search light. So I think this will cover both areas needed hopefully. None of my rides take me near pavements either and my seaside town is very quiet mostly.

I only sat that old 50w led on the cpu cooler in the light to show how you can get 2x100w led chips (50w and 100w are same size but more chips) in these housings but would have to run them at 1amp each max. At 1.3amp the chart says they can put out 5000lumens so Its a bit of a silly idea really but since when have we done things cos they make the most sense here lol.

Those leds have an odd ramp of efficiency. Its like 5000l at 1.3a and 8000l at 3a and three times the heat. Doesnt seem worth dealing with the heat Il just stick to 1.5a maybe. I can barely see the difference between 1.5 and 3amps anyway when I tested it on a cc boost circuit due to your eyes/brains interpretation of light brightness levels as they compensate.

Here is my boost box and is a perfect tiny little device for leds but you cant get to the diming current without a teeny screwdriver for OTF adjustments. Plus as its CC it seems to heat the led quicker than pwm. Will have to test that out when it all arrives. Cheers for the input again. You think led-battery-light simple but it never is these days lol

http://www.ebay.co.uk/itm/300811033000?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

 

[bionicdan]

Just for reference if anyone is building one of these.

I got my 10a driver and the led only seems to pull around 2a from it on max at 10xlife cells. So no panic with over driving it as the led almost seems to self limit current wise. Due to sag in my tiny 10ah pack I had to up the cell count by one or it went out uphills if you set the controller to 40a warp mode.

I have 100 chips at 35x45mil (1-2w chips i think) and wow its bright now. I have an led on the way that is the new 3w 45x45mil chipsx100 that are underdriven at 1w each. Even at 1amp its almost like my car headlamps so I will never again ride through dog poop at 30mph ha ha.

Will post a night time vid when it turns up and picture when its installed properly

18usd or 11.5gbp

http://www.ebay.co.uk/itm/251204554523?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

 

[bionicdan]

FINAL BUILD SETUP WITH 10-16000 LUMENS.

Thanks for the advice, It turned out I just put a switch in the negavitve pot feed to flick from max to what ever the pot is set at Woo too easy that was, wow its bright

http://endless-sphere.com/forums/viewtopic.php?f=3&t=47991&p=705657#p705657