Easy Driver Question

I just picked up a pewter mag 2C at Home Depot for $15. Really a nice hunk of metal for the money. Anyway, I've got a question that I thought would be simple to answer but my research has come up short. What is the best driver to power a 3W LED at regulated 750-1000mA from 2-C's or 2-25500 NiMh cells? By "best", I mean with good regulation and good efficiency. So far, this is what I know:

TaskLED: Maxflex & Fatman require Vin of 2.5 & 2.7. Won't work with 2x1.2V NiMh cells, right?
The Shoppe: BB Nexgen 1000 current regulation starts at 3.4V. Again, no good for my Vin of 2.4V.

I'm thinking that the Madmax Plus might be the closest I can come, but Iout max is only 700mA. I also saw this one at Kai: http://www.kaidomain.com/WEBUI/ProductDetail.aspx?TranID=3150, which appears to do somewhat of the same thing plus has multiple modes and is much cheaper.

So what's the consensus? Thanks very much for the help!

Georges80 has a limited supply of VIP drivers,available in either 750ma or 1000ma.Works great off two Nimh.See here http://www.taskled.com/techvip.html

Thanks Texlite. That seems like a perfect match. I've got a PM in to Georges80 to inquire about availability as the VIP sales thread is several years old. To be honest, I'm really surprised that there is no more widely available device meeting my specs.

Here are the three available choices I have found:

I have used at least a dozon of these DX drivers although I have found that these can overheat and fail if driven for more than an hour off of high capacity D nimh cells. If you stick these to a heatsink with thermal glue you should be fine.
700mA 2.5W Regulated Circuit Board for DIY Flashlights (3V Input) 5-Pack $9.95
http://www.dealextreme.com/details.dx/sku.4382

I have ordered some of these which look promising, can't say until they arrive.
(5pcs) 1AA 3W LED Circuit Board (0.8V-7V)Product Information for KD#: SKU3151 Our Price : $16.99
https://www.kaidomain.com/WEBUI/ProductDetail.aspx?TranID=3151

These are my old standby, 500mAh drive level or 700mAh using two in parallel. I just wish they didn't cost $10 each....
Super High-Output MicroPuck 2-Cell 1W LED Drive Module
Designed to efficiently power a single Luxeon I, or strings of 5mm LEDs, using two 1.5 volt cells.
http://www.ledsupply.com/02009-sho.php

Thanks Mr. Light. I just ordered that 5-pack from Kai in case the VIP drivers don't work out. I guess it is as I thought - not many options when it comes to driving a 3W LED to the limit off of 2 NiMh. Seems like there would be a HUGE market for such a thing, but I guess the whole world is using lithiums or those AA battery carriers to increase the voltage. Or maybe we're both missing something!

SnowplowTortoise said:

Thanks Texlite. That seems like a perfect match. I've got a PM in to Georges80 to inquire about availability as the VIP sales thread is several years old. To be honest, I'm really surprised that there is no more widely available device meeting my specs.

Click to expand...

Yeah,I looked for what seemed like forever for a 2 cell driver capable of 1000ma.You can run two micropucks (500HO),you wont get the full 1000ma though,and your efficiency will suffer(twice the loss).By the time your figure two pucks at $9.00 each and shipping your almost at the cost of one VIP 1000 which is $22.00.The micropucks are great drivers,just not in this application.Also Dealextreme had suggested that he had some 1000ma multi-mode boost drivers coming sometime in the future.Keep an eye out for those.This thread has some great information https://www.candlepowerforums.com/threads/168156. Anyways,the VIP drivers are available now,in the link I posted just go to Order Products at the top of the page,then scroll down to the bottom of the page.George builds great products and is very helpful.

SnowplowTortoise said:

Thanks Mr. Light. I just ordered that 5-pack from Kai in case the VIP drivers don't work out. I guess it is as I thought - not many options when it comes to driving a 3W LED to the limit off of 2 NiMh. Seems like there would be a HUGE market for such a thing, but I guess the whole world is using lithiums or those AA battery carriers to increase the voltage. Or maybe we're both missing something!

Click to expand...

Your right,theres not much available.And yes,it seems to me there is a HUGE demand for such a driver at an affordable price,especially a multimode driver.Im going to order some more of RV7's drivers for 1AA,maybe I'll ask him if he could produce some 2 cell boards.If theres enough interest maybe he will.These would be the perfect boost drivers it would seem to me,3 levels with or without strobe,and very efficient.RV7's work is fantastic.

Well, I now have two VIP 1000s on order from George and 5 multimode 700s on order from Kai, and only 1 host body. Looks like I need to make another trip to Home Depot. Texlite, I hope you are able to convince RV7 to make the 2 NiMh version - I'll be watching out for that.

Thanks again for the help guys. I need to stop spending money now so please don't offer any more good suggestions!:laughing:

You have the same problem I had when I decided to make a 2D mag (see link below). I took the easy option and used micropucks which works fine.

Having read all the above it would appear there are a few more driver options now, maybe it's time for me to make something again..........

I didnt think about this the other day ,but Wayne over at the Shoppe has some drivers that will deliver 1000ma when run from two nimh.

Which one? None of the ones I identified through the flow chart would work.

Just came across a link to this thread from another post,sorry for the long reply time.Both the BB Nexgen and the GD series will run off two cells,I checked with Wayne to be sure and he confirmed.Sorry again for the wait.