LF: xiphmont's LED driver board (TLD)

[atagunov]

xiphmont apparently has moved on to other occupations
only wayback machine remembers his exploits
anybody got his TLD - Thinkpad LED Driver board for sale - either populated or unpopulated?

Thx!

[zoltan87]

Wow you are right, his incredibly detailed webpage about Thinkpad LED conversions is completely gone! I huge loss, as it contained so much useful info, not just about his kits, but in general about the whole LED conversion procedure, expectations and much more.

[chowbear]

I have some unpopulated boards, however to be honest all I did was download the gerber files and get them printed in china. I think jlcpcb will do you 5 for a couple of dollars I can send you the files if you like?

[atagunov]

I have some unpopulated boards, however to be honest all I did was download the gerber files and get them printed in china. I think jlcpcb will do you 5 for a couple of dollars I can send you the files if you like?

Wow please send me all the files you've got! You wouldn't have any further docs? Schemas, lists of elements, where to place what? Perhaps some tuning instructions?

PM-ing you my email in a moment..

[jaspen-meyer]

which board are you looking for?

i.e. which machine will it go in?

[atagunov]

which board are you looking for?

I'm slowly collecting parts for a T60/T61 Frankenpad. I'm well aware that ex-factory LED backlight on Boe Hydis panels can be powered up in a relatively simple manner via 4 wires soldered on to the stock inverter (+it's advisable to remove transformer from stock inverter). However I'm keen on the project of powering LED backlight on that panel via Xiphmont's board. I believe this should also be possible. The idea is to eliminate flicker at hardware level entirely. People rightly tell me there's very little motivation too, but I just WANT to do it BTW I already got that plug that goes into Boe Hydis backlight socket.

chowbear kindly sent me an archive with Xiphmont's designs. Thx a lot! Shamefully I haven't checked yet what it contains. Perhaps eventually we can get permission from Xiphmont and put some of that archive online somewhere. Or maybe he changes his mind and finds time to put it online again himself.

I'm actually trying to get a good bunch of soldering equipment delivered. This project is part of my excuse for ordering that. I kind of always wanted that equipment (YUHIA 939D for example + tips..) and now I have some albeit rather small reason. On the other hand I do not enjoy the idea of ordering the required parts.. it's probably going to be tedious

Jaspen, have you got some documentation or some boards as well?

[wileE]

I have a X61 kit with a xiphmont TLD2 (300 mA output) board. Would you be interested in that?

[RealBlackStuff]

AFAIK the T6x inverter supplies +5V to the CCFL-trafo or (when LED-modded) to the LED-PCB on the Boe-Hydis HV150UX2-100 screen.
I've never tried it, but according to the LCD-specs, the LED Power Supply Voltage can be up to +28V.
Also, I once had a defective LED-screen, which I "fixed" by cutting out the LED-PCB part from a cracked screen and taping that on the defective one.
Which means that you could probably "tap" in the 20V motherboard circuit and feed that to the LED-PCB.
If that works, you could be almost "blinded", seeing how bright 5V already is!

[atagunov]

I have a X61 kit with a xiphmont TLD2 (300 mA output) board. Would you be interested in that?

Thank you very much for getting back to me!
I guess I'll play a bit and see if I can make my own copy by end of this year..

If it doesn't work out I may ping you for your board then
My plan is to try to make a TLD3 (with potentiometers), this is why I'm not jumping right away at a TLD2 (with fixed min/max current)

[chowbear]

Ah, so you are only interested in the driver board and not the LED strip itself? In that case I reckon your project should be much more doable since sourcing the Nichia LEDs is the most difficult part. I was going to suggest going with a Yihua 853d or something with a built in hot-air gun to help build the LED strip and to desolder the components on the inverter board but maybe you wouldn't need it. As RealBlackStuff mentioned you can probably get away with just removing the coil and hijacking the appropriate signals to your LED controller board.

So far I have managed to build 2 TLD3 boards and an LED strip, however I could only test my very first prototype before I accidentally crossed VCC and ground on the inverter board (!) while testing the second one so if you do need a TLD3 board in the future I could offer you my dodgy prototype board. Fingers crossed that you'll be able to successfully build your own though! Also if you are worried about the tedium of sourcing components, I recommend going through the notes I sent you! There should be links to components (mostly Aussie sites) and alternatives for ones which are no longer available.

[berrieds]

I'm also looking to recreate, in some fashion the LED Mod by xiphmont. I've looked everywhere for the files, and the best i can find is some PNGs for the TLD4-X6 that were saved by the wayback when machine.

I'm sent a PM just to ask for any of the relevant files so that I might be able to recreate the LED mod myself. I have a few UXGA screens with failing CCFLs, so I thin kthis would be worth a shot. Maybe replacing the entire inverter with the TLD4 would be the best option, but I'm not sure if that is possible.

Or should I try and find a suitable one from China rather than trying to recreate all xiphmont's work?

[atagunov]

hi, I imagine you'll have significant difficulty in re-creating led strips; re control boards I understand Xiphmont's designs allow us to have less flicker (none at all in fact) and have control knobs to tune max/min brightness; they also probably allow a wider range of brightness adjustment. That said I haven't even looked at the files myself and ordering all parts will probably take some time. Would be happy to pay a little for ready-made PCB-s should anybody be ordering them

[atagunov]

Purely hypothetically, how many people would be interested to receive a kit containing all needed parts + PCB ?
I'm thinking perhaps some nice person could do the orders, put parts into envelopes and send them to us?
I'm talking about TLD boards here NOT the LEDs which are their own story.. I'm talking about kits with parts NOT soldered

But how many would we want? I'd want between 2 and 6 depending on the price I guess, maybe 4.
Anybody else?

[zephray]

In the TLD3 board design, the feedback resistor is chosen as 0.332 ohms, with 0.2V of the reference voltage, this should translate to a 0.2/0.332=0.6A or 600mA, this is also confirmed by his own description on the website. He also mentions the LED backlight draws 4.8W at 600mA current, this means the voltage goes into the strip should be 8V. Single LED uses 2.5-3V, so the only possibility is that he put 3 LEDs in series as a group, then put a lot of groups in parallel. From the Gerber, each group is 9.1mm in width. He mentions that the lit area (or length) is 246mm, so there are 27 groups on the LED strip. 600mA / 27 = 22 mA.

Well unfortunately this means TLD3 won't work with HV150UX2. Monty's LED runs at 8V 600mA, the voltage is lower than the battery voltage and power supply voltage, so a buck (down) converter is used for driving the LED. In the HV150UX2 case, the LED is expected to run at 28.8V 120mA, the voltage is higher than the battery voltage or power supply voltage, a boost (up) converter is required. The TLD3 board simply wouldn't be able to lit up the HV150UX2.

[atagunov]

Thanks a lot. I would still like to get several TLD3 boards, even if they won't work with HV150UX2.
Is there a way for us to do a group buy here?

I would be happy just with a bag components + PCB-s.
I think you mentioned in a private exchange that it might be possible to order the boards assembled but untested. That would be good for me too.

My own appetite is between 4 and 6 boards.

[RealBlackStuff]

To make the HV150UX2-100 work in a 15" T60/R60/R61/T601 I have done numerous LED-mods.
According to the specs, that screen has Back-light Power Supply Voltage min-7.0V, average 12.0V and max-20.0V
From the T60/T61 inverter I connect power from the fuse that is connected to pins 2-4-6 on the inverters' LCD-connector (to the LCD-cable) and feed that to pins 1-2 of the 14-pin connector on the LED-PCB part on the back of the screen.
To be honest, I've never measured its voltage.

[m11k]

Coincidentally, I happened to measure the voltage out from a modified inverter over the weekend and I see 20V.

[atagunov]

Okay, there is a legitimate concern TLD3 will not drive HV150UX2-100. That's okay. I don't plan to fit all my 15" machines with HV150UX2
Let us still do a group buy of TLD3 assembled boards or kits consisting of parts + a PCB if we can..

P.S. if I ever get a chance I will try to pair TLD3 with a HV150UX2 but this is not my main purpose here

[Kingair]

Definitely interest for kits for the X61 !
Keep me posted

[chowbear]

Hey guys! I actually originally ordered a whole bunch of extra LED strip and TLD3 PCBs which means I have about 18-19 spare boards of each in this case. If you are interested in only the LED driver board then I can definitely help you out there and whip up some as I have enough parts for maybe 5 more TLD3 PCBs and can easily order more parts as required. Just send me a message! The only problem is that they'd most likely be untested as I unfortunately don't have a X61 as the current asking price on ebay is ~150 USD.

As for the LED strip I'm currently trying to source some Nichia LEDs however it seems that they are not very popular and hence production of these LEDs are very low and they cannot supply specific colour bins. With Xiphmonts original strips he was able to specify that all LEDs be selected from 1 of 18 colour bins spanning 0.08 of the CIE Y coordinate.

My worry is that the new LEDs would have a potential 8-fold increase in colour variation, however I'll check if this is the same situation for production runs from different years...

Also I was a bit confused as well when I tried to crunch the numbers on Xiphmonts original LED strip design! The LEDs he were using each had a forward current of 85 mA, which meant that 600 mA seemed to be far too low to supply enough current to the strip but I'll also admit that my understanding of LEDs comes entirely from the wikipedia entry...