Forum menu
It's pretty simple really - sight has evolved with sunlight, so our eyesight is best suited to wavelengths in that spectrum (orangey/yellow).
Amber LED lights, anyone?
All very interesting . . . just back from a 2 hour run round the local hills with an XP-G triple bar lamp and an XP-G triple helmet lamp, the bar one is the Lumi HID conversion I did and the helmet one is a standard lumi halogen case running with the eBay 970mA regulator with my own 7mm thick slug behind the LED's . . . a very tight fit which I wasn't sure I could get it to work . . . but it does, just . . .
So long as you keep moving the small case temp is fine, but if you stop for any length of time you need to switch off, it only takes a few minutes for the temp to start rising rapidly . . . but I can live with that . . . this is with an ambient of only a few C . . .
One thing that is noticable is that the helmet lamp appears brighter, when in reality it isn't . . . I guess it being more or less co-axial with your eyes makes for better reflection . . .
Anyway . . . on the colour balance side of things, I don't notice them as being markedly blue (when riding) at all . . . I also had a 20W lumi halogen to make some comparisons and it looks terrible, dull, and nothing like as good (and twice the power consumption) . . . the LED output is very nice, makes a HID look very monochromatic . . .
Anyways, on the way back down the hill I have to use about 600M of more or less single track public road, unlit (middle of nowhere), between trails . . . I had both lights on full bung, and encountered two cars, both pulled into passing places and stopped as I passed 😉 . . . I guess they can't work out the two vertically placed, very bright, lights are so stop (sensible drivers around here) . . . 😉
Sounds spot on FD.
just printing postage labels etc ready for posting all this order.
Hopefully people will post on here to say how they have gone on with their conversions.
about to swap my XRE for the triple XPG's.
300-400 lumens extra for no extra drain, just what the doctor ordered.
ironically some of the guys we ride with think that a car is behind us on the unlit roads when me and a mate are riding alongside each other. 😆
Chucky
when I am just behind you with my lights I just thank god we ban Lycra on our outtings!!!! 
Nige, When you are behind me with your twin set-up I can see bugger all!! Even with 1000lumens
and for that i'm wearing Lycra next week 😈
fergusd - some questions:
How did you establish you need to turn it off?
Does your driver have a thermal overload? and is it being tripped?
Have you got any external heatsinking?
I'm using the bFlex driver with 5 power levels and I was planning on dipping it to lowest level when I stop, so I don't blind people for one thing and to control the temp. Hadn't planned on having to turn it off though.
> How did you establish you need to turn it off?
Burned fingers after 10 minutes spent watching a herd of deer.
> Does your driver have a thermal overload? and is it being tripped?
No I'm using the 5 quid ebay job rather than the 20 quid bFlex, secondly I have no use for bFlex functionality in a helmet lamp and lastly given the heatsink slug I am using there is no room for a bFlex. A bFlex in this case is a waste of money.
> Have you got any external heatsinking?
Yes but not fitted 😉 . . . My ideal objective is a lightweight helmet lamp, any mass reduction is welcome and I thought I'd see just how usable a non heatsinked version was . . .
If you reduce current to 500mA with the XP-G the heat output is negligible . . . so cutting to 1/2 power means you have no heat issue . . . I'm runing things at 1000mA (max drive current) where heat is much more of a problem . . .
Thanks fergus
Maiden voyage with mine tomorrow night. Max setting is 1000mA but I do have an external heatsink. Plan was to run the majority of the time at less than full power and only crank it up when I really need it.
Have a good one, you'll be fine on max all the time in this weather . . . enjoy 😉
@Chucky
If you somehow end up with enough spare bits for a Lumi can conversion, let me know, I'd be interested. Can source a driver myself, really just LEDs and optics I need, but a spare driver wouldn't go amiss.
Ta.
You might be lucky Dr, i'll let you know in a few days.
It will only be the LED and optic though.
No problem @Chucky, that should be enough to tinker with when I get round to it. Let me know what you got and how much, email in profile.
Have been running my Lumi can as per Chucky's build but with XPG's for a couple of days now. On my 45 minute commute the can hardly gets warm, which I've found a little strange. I'm hoping it's not getting ed hot inside!!! (It used to get very hot with my 20W halogen). The light is more 'white' than the halogen but brighter IMO.
If you are only driving them at 650mA then they won't produce that much heat . . .
Regardless . . . your halogen bulb was about 2-3% efficient so produced about 17 watts of heat . . . your LED setup is probably ITRO 20% efficient and in your case probably only produces ~5 watts of heat . . .
Sorry to be very lazy and not reading this lot, but I have the old 13.2V Halogen lumi set sitting doing nothing. Is this convertable?
There is currently a shortage of drivers, has anybody tried to squeeze in the 650mA version with screw terminals??
There is currently a shortage of drivers, has anybody tried to squeeze in the 650mA version with screw terminals??
I was thinking the same, So I bought one and then I was going to De-solder the connector. The MINUTE I paid for it and I get an email from the seller saying that the solder connection drivers are due in at the end of next week.
Typical. 🙁
*Update* the seller has agreed for me to swap a connector type for the solder type when they arrive. What a gentleman. 😀
The guy selling the drivers on eBay seems like a sound chap. I contacted him regarding the inner workings of the dimming / shutdown pin and he put he straight on to the data sheet of the main chip used in the circuit. I could now bypass him completely and reverse engineer his board, but at that price, there's not much point.
We all have troutie to thank, he pointed me in the ebay guy's direction.
and just to add the ebay guy is 'spot on', honest and very well priced.
I bet he wonders what the hell has happend in the last 4 weeks 😆
He never had quite the same demand before we got the Lumi casing thing to work.
Just as an aside, you guys have had more running time with these lights than me. I've hardly been out these past 4 weeks due to work. 🙁
The idea behind it was just to make a commuting light. The halogen case was used because Lumi do a glowring for it, which I thought was a great idea for commuting.
But now, thinking about it, with a smallish Lithion battery (circa 2.2amphr) it will probably make a great helmet light given it's low weight.
Piccies and more opinions when these are all built please.
Happy soldering.
The maiden voyage with mine went swimmingly last night. Very pleased with the amount of light and the beam pattern from the Cutter Cute 3 optic.
Had it running at full tilt (1000mA) for most of the ride and it hardly got warm at all (it was -2deg though).
I'm considering converting my other Lumi can in the same way but with the quad board instead.
Should also be picking up the CNCd housing for a x7 XPG bar light today.
I'm getting rather carried away with this home building malarcky. 😀
Chucky - that's exactly the setup I used last night (see pics in earlier post). I'm using the 2.2Ahr Li-ion battery from my original Hope HID fastened to the shoulder strap of my camelbac. Very neat and much lighter than the Hope head unit.
I haven't run the battery flat yet but sensible use of the lower power levels should eek it out over 3 hrs.
Just completed the conversion on junkyards Nightpro headlight.
I must admit it was easier than the lumi one due to a little bit more room. The light is very neat and the switch integral. Used the switch as an off and on rather than a 1/2 power. The switch housing retaining screw even locates into the heatsink ensuring an good contact with the casing.
a couple of piccies of it here.
[img] 
[/img]
[img] 
[/img]
[img] 
[/img]
[img] 
[/img]
[img] 
[/img]
[img] 
[/img]
[img] 
[/img]
[img] 
[/img]
Hi i have 2 of them ebay 970ma drivers that i no longer need if anyone wants one £6.50 each posted email in profile cheers.
Anyone tried a conversion on one of [url= http://cgi.ebay.co.uk/CNC-Alloy-Halogen-Bicycle-Light-Lamp-Lumicycle-Compat_W0QQitemZ250538099651QQcmdZViewItemQQptZUK_SportsLeisure_Cycling_Bike_Lights?hash=item3a553c03c3 ]these[/url]? With nearly three inches front-to-back there should be loads of room for more LEDs, a good heatsink and a driver board.
I think you should be able to get the cutter LED's on a MR16 board (50mm) as opposed the 35mm MR11's ones used in this thread. If you can it should be spot on with a suitable heatsink.
I don't have any LED's left BTW Doctor, sorry
Damn it. Tried the conversion and followed instructions, but it wouldn't work when finished. Can't see why, checked all the soldering as i check the LEDs the damn track peeled off the board.... yay i get to fork out for another LEd board and wait for it to arrive.
Plus i get to convert it back to standard so i can use it tomorrow.
I'm not happy!
sorry to hear that wishiwascalledsteve, if you get stuck again mail me.
Dave received the stuff yesterday...BIG thx for organising it etc!! Just waiting for the Ebay drivers now, went for the 970mA ones 🙂
DrRad, I think those kits are from OldGit off here??
I was just wondering if people were managing to disassemble the lights OK, say to upgrade the LEDs or driver board?
The heatsinks i've made are quite a good fit and i'm not sure how easy they'll come out once all the wires are in place and the heat transfer paste has been added.
@Chucky - doesn't look like Cutter do 50mm optics, looking elsewhere. Thanks for letting me know about the LEDs, will possibly head up another group buy if I end up doing a Cutter order.
mjb - I've seen the heatsinks tapped, so that you screw two screws in to aid extraction. Look at [url= http://www.elisanet.fi/kai_js_nurminen/ ]this guys site[/url] under DIY lights
I hope the Mods don't mind me posting on here - I'm 'The eBay guy' who sells the LED drivers. I was pointed to this thread and thought I could offer some useful comments for anyone who is going to try this.
The new batch of PCBs is due tomorrow so unless I've made a horlicks of the layout I should have more drivers built up ready for the weekend.
I've noticed a few people are using the half-power mode. If there is interest, I can configure the drivers so you get half-power simply by connecting the 'A' and 'IN-' terminals via a switch - you couldn't get the shutdown function this way though.
Also, people are talking about thermal issues. It should be possible to add a large thermistor between the 'A' and 'IN-' terminals to reduce the current as the temperature increases. The only down-side of this is that you will no longer be able to get 100% output current. I would suggest something like a 1M NTC thermistor with something like a 470k fixed resistor in series. Using something like order code 61-0458 from Rapid Electronics, this has a resistance of 2190k at 10C, 1000k at 25C, 309k at 50C and 133k at 70C. The formula R / ( R + 200k ) gives the fraction of full scale output current for my drivers so at 10C you would get ( 2190 + 470 ) / ( 2190 + 470 + 200 ) = about 93%. At 25C you'd get about 88%, at 50C about 80% and about 75% at 70C. Decreasing the value of the fixed resistor would reduce these percentages if this doesn't keep the temperature low enough.
The net result of this mod. should be that you get nearly full output when moving and the air flow is keeping the light cool (i.e. when you need it most) but when you stop the thermistor will react to the temperature rise and reduce the current to limit the temperature. Light output will drop when this happens but that shouldn't be a major problem when you are stopped.
You should be able to still use the half-power mode by running the 200k resistor in parallel with this circuit. You'll actually get slightly less than 50% as at 25C the thermistor circuit will reduce the 'effective' resistance to 176k but I doubt you'll notice the difference. You will lose most of the thermistor-induced current reduction when in half-power mode but that shouldn't be a problem as you are running at a much lower current anyway.
I'm looking at ways to mount both driver and LEDs on the same circuit board but unfortunately my PCB fab can't do thermally enhanced boards so I need to look at alternatives.
I'm also looking at different driver ICs including one which takes a lower input voltage than the Vf of the LED string and one which has a higher output current limit. These aren't imminent though, especially the latter as this requires me to work out how to solder a tiny chip by hand... Also, I am doing a version of my standard driver that has a PIC microcontroller on-board which will allow better temperature compensation and push-button control of the light level.
If anyone has any questions I'll happily do my best to answer them provided by doing so I'm not breaking forum rules.
Welcome to the world of STW.
Nice to see somebody spending time to see what we would like to have on future drivers.
slightly smaller would help if possible. especially for these Lumi halogen installations.
Nice product by the way and very well priced.
keep up the good work.
The new version of the drivers is slightly smaller, but only by about 1mm all around. A quick warning that the order of the terminals has changed! It is difficult to decide the optimum size as the components of the driver also generate heat so I decided to go for a larger board the aid dissipation (the original version was a fair bit smaller but was originally only designed for 1W LEDs). I could go smaller for 3W LEDs but not really for 5W ones unless you want to worry about cooling the driver as well!
I may have the opportunity to get some more PCBs made in January. Would there be any interest in a version of this driver with the components on-board for the thermistor and half-power mode? All that would be needed external to the driver would be the thermistor itself and the power switch. This would be a cheaper solution than the version with the microcontroller on-board but with less functionality.
Any other requests? As long as I can sell enough to cover my costs I will consider doing 'specials'.
Excellent, BlackCatTech thanks for jumping on board.
I was looking at your e-bay items the other day & saw you had no solder-on drivers in stock. I'll be keeping my eye out & placing an order once they are back on.
Need to really pull finger out and get it all ordered. I made a list and everything, but have yet to make a purchase. Should really get the Cutter order underway, as that'll probably be the longest lead time.
Lot of functions on boards are nice but I generally only use the Duo mode (Hi/Lo) & the over temperature protection on the bflex so a driver with those (on board thermistor sounds good) would be great.
Also the option to buy with 4 inches of wire already soldered to each of the driver terminals would be useful.
nockmeister - Member
mjb - I've seen the heatsinks tapped, so that you screw two screws in to aid extraction. Look at this guys site under DIY lights
I did think about that but assumed that the LED board would cover most of the heatsink and so they'd be no space left (i'm still waiting for the bits from cutter to arrive to check this).
Boards are here, I've built and tested one and all looks good.
For added stylishness (not that you'll see them inside a light fitting...) they are now Black.
I'm waiting for a few components due today before I can build a large batch but should be able to list on eBay tonight or Friday.
I should warn people that prices may have to go up in the New Year - my costs have been rising for a while and I've tried to absorb them but with the VAT going back up I may not have any option.
I'll look at the board changes mentioned but as I'm having to piggy-back these on another PCB order this is unlikely to be ready before the end of January. Is the shutdown function still desirable, or are people happy to use a main power switch? I ask as every terminal I need to add will increase the PCB size so if shutdown isn't needed I can probably save a bit of space.
Are the 3W boards avalable in 970ma? I've fitted the 650ma one and there are no heat problems so I'm thinking of changing it to a higher output to get more lumens. A 970ma board with a built in resistor to reduce the output to 50% would be ideal...
from my point of view the shut down requirement is lower priority than the 1/2 power and temp.
To have a driver with those two additional features would be great.
Squeakybrakes: The board is generic to 1W, 3W and 5W versions. The 3W and 5W also share all but two components. The power ratings are a bit misleading - no two LED manufacturers seem able to agree on ratings. The current rating is the most reliable figure to use as LEDs are current-mode devices. As standard the units are available as 330mA, 670mA and 970mA. I can do pretty much any variation under 1A as a special as long as I have the appropriate resistors to set the current.
Is it worth listing versions with a half / full power mode instead of a shutdown function? Cost would be the same, it's just a case of changing one resistor on the board.
Does that mean that the 970ma can be used to drive the cutter board with 3 x 1W LEDs? The 1/2 power option would also be my preference.
Brilliant stuff...BlackCatTech,any chance of getting my 2boards modded for full/half power(it's Ian BTW)?? Yes deffo worth advertising with the functions you have mentioned rather than shutdown.
mjb - well if you only use thermal compound rather than thermal adhesive you would just need to remove the pcb to get access to the extraction threads. I'm not sure but it might just be as simple as drilling through the pcb???