Lumicycle Halogen to LED conversion with piccies and a step by step guide.

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.

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 these? 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 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???

Seconded request for the boards to be available with wires already attached as this would allow easy lash-ups… errr… I mean prototyping with screw terminal blocks.

Ian: No problem, should be able to have these ready for tomorrow afternoon if you are about to pick them up.

Squeeky: Can you post the link to the LED board you mean? 1W LEDs are usually 350mA so while you could run three in parallel, that isn't usually recommended for power LEDs.

All: Will look in to options with wires attached. I'm not sure what thicker wire I have – 7/0.2 is rated to 1.4A but it's always better to use more substantial stuff to minimise losses in the wire itself.

I will also do a version with the half-power option. For this you would connect 'A' to 'PWR-' for half-power mode, and leave it unconnected for full power mode. You could add the 1M thermistor between these terminals with the switch shorting it out for half-power mode. You would then get 92.3% power at 10C, 85.9% at 25C, 72.6% at 50C and 63.8% at 70C

Hi BlackCatTech…yep no problem, I'll bob over at 3pm if ok?

Just thought I'd mention that the drivers are now available on eBay again. I've listed a version with the half-power dim mode as well as the standard ones. I've not had the chance to look for other colours of wire so I can't offer pre-wired ones yet, probably Monday now.

I also had a good long chat with the Nockmeister today and it sounds like some of the other things I have up my sleeve may be of interest. I'll try and get them complete as soon as possible so keep an eye on my eBay stuff.

@BlackCatTech – be interested to see what you have up your sleeve, please post here when they're available so we know to look 😉

Any switch recommendations for Lumi cans to go with the 1/2 power option Black Cat drivers?
I'm presuming that a 3 positon switch will be needed? Looking at Farnell's site it's all a bit overwhelming!

@zangolin – you could go with the original Lumi switch and just unplug to switch off.

Otherwise, go with type F here:

http://www.maplin.co.uk/Module.aspx?ModuleNo=2341

…and use one of these toggle covers:

http://www.maplin.co.uk/Module.aspx?ModuleNo=2348

…if your original Lumi cover is no more.

Use one half of the switch to switch the power, the other half to switch the dim setting on. I'll try to do a proper wiring diagram if anyone needs one…

Otherwise, go with type F here:

I thought that too, but found that the fatter base of the DPDT switches like that one don't fit in the Lumi can if you want to use the existing hole.

If using the standard Black Cat driver, then it's easy enough to use a SPDT switch such as the Type B Maplin one to have a configuration such as off-full-half (where the off mode is a soft off, so technically not quite as off as unplugging the power cable, but effectively the same), by using the control terminal and a resistor. The instructions that come with the drivers are excellent.

People should be aware that with the 'Dim Mode' drivers the off-full-half option is not available. To turn off you need a separate switch in the power rail.

Using a double-pole, centre off switch you can use one pole to switch the power and another to control the dimming. For example, if you have a double pole, centre-off switch you can wire the 'common' on both poles to 0V. Connect *both* sides of one pole together and run these to the 'PWR-' terminal (IN- on older drivers). Then connect one side of the other pole to the 'A' terminal. (Connect via a 200k resistor for standard drivers, direct connection for dim-mode drivers)

You will then have full – off – half. Not ideal as you have to go via 'off' to change mode but still an option.

The Dim-mode drivers have the resistor described in the data sheet built in, the down-side of this is that you can no longer access the control terminal directly so can't put the driver in to shut-down mode. Next time I get some PCBs made I'll do a version that has both half-power and shutdown modes.

If you are looking for switches I find Rapid Electronics are fairly good and cheap – the trouble is that unless you are near Colchester you need to spend £30 to get around the handling charge. The problem there is that they have so much interesting stuff you can easily spend that much on things you don't really need…

Nice One Steven the 2 mode on the drivers is a good upgrade and a lot less faff for the users .

I have used quite a few of your drivers and have to say they have been solid little things .

Be interested to know what else you have in mind

Fantastic thread!! I have often heard people with almost zero electronics knowledge argue in favour of the pricing of high output lights. The component prices are very low in comparison to the shelf price of an engineered system, but the mark up is such, that you have to have deep pockets or be very very enthused to take the plunge.

I have had three lots of halogen lights, my first set was acquired in 1998. I paid £75, but thought that was a bit steep at the time. Since then, firms like Lupine have driven prices into the stratosphere.

Just had a look at one of the beautifilly engineered lamps from my ageing Cateye ABS35 to see if there is enough room to facilitate one of these high power upgrades. I'm out of luck as the driver would never fit, plus the heatsink fins on the inside would make getting a thermal bridge to the body rather troublesome (if not impossible). Shame since I was once trained to MOD standards ans spent 2 years manufacturing electronics assemblys for things like weapon control systems on fighter aircraft.

I thought i'd see how much a set of lumicycle lights are and am shocked to find their halogen set ups are now £60 more than they were when I last looked (£200).

WHY ARE DECENT BIKE LIGHTS SO STUPIDLY EXPENSIVE? 👿

@spongebob
It must be the outlay>units sold I assume. You think in the grand scheme of things it's only us night riders or 24 hour'ists that buy them.

@spongebob

WHY ARE DECENT BIKE LIGHTS SO STUPIDLY EXPENSIVE?

As my mother would say: because they charge what people will pay. Same reason a cup of coffee can set you back £3

As others have commented part of the cost is simply due to the significant outlay needed to build these things. I'm lucky that I found a good PCB fab that allows me to mix a number of board designs on a single panel as otherwise I probably wouldn't have started doing these drivers. Even then I have to outlay enough to buy components in 100s to keep the cost down so I'm reliant on selling a fair few quickly to pay off the credit card bill.

It is a similar problem for the casings – you need to pay someone to do the tooling or CNC programming and there will probably be several parts required so you could be looking at thousands in set-up costs alone. You'd need to buy a significant quantity to get the unit cost down to a realistic level and unless you can be sure of selling a significant proportion in a short time you run in to cash-flow problems.

I'm certainly interested in looking in to doing a complete system – I can tailor the electronics to suit giving packaging advantages – but until I find a good CNC company with low set-up costs I'm struggling. Of course once you start doing these things commercially you also have a much bigger paper-trail to follow, you have to register under the WEEE directive, have to prove the units meet CE standards etc. If you can be sure of selling things in the millions like radios, DVD players etc you can pretty much ignore these costs but if you are talking thousands then they become more significant I'm afraid…

A quick overview of other things I'm looking at for Troutie and anyone else interested:

Osram do a version of their 'Dragon' range with lenses built in. I've combined one of these with a Linear LTC3490 on a single board to get a pretty decent commuter / head mounted light powered from 2x AA cells. Only trouble is packaging it to be waterproof. I'm meaning to start selling these for DIYers soon.

I've got a version of the driver board with a PIC built in. I'm planning to have this with either a thermistor for temperature control or with a battery monitoring function that lowers the output when the battery gets low as a 'get you home' function. I'm planning to have the option of either a pot for full-range dimming (not so useful for bike lights I'd suspect) or a push-button to cycle through various power settings.

I also have a circuit that can boost from a single Lithium cell to drive 2x LEDs. Not sure if it will manage 1A or just 700mA – will have to try it out! This is based on the National LM3410 which shut cut-out at around 2.7V which is ideal for protecting lithiums from over discharge.

Future plans including trying to hand solder the Zetex ZXLD132x range and trying out a 0.8mm FR4 PCB with plenty of thermal vias and 3x Cree LEDs plus driver on a single board. Getting heat away from this one may be a challenge but if I can solve it (or find a fab that does thermally enhanced PCBs cheaply) then that will be a great combined solution.

Main trouble is that I've got a reef aquarium system with a touch screen controller to get finished as an urgent priority so these will be a while in coming I fear.