DB & Wiz2 Sandwich questions

[StoneDog]

I would like to use a 14500 Li-Ion in a mini-mini-mag to drive a 1w at or slightly above spec.

My options appear to be:
1) Build a downboy 400 or wizard 400 sandwich.
2) Wait for the next generation wizard board.
3) Build a resistored DD "sandwich" /ubbthreads/images/graemlins/icon15.gif.

If I build a downboy/wizard sandwich, do I need to isolate the LED's - connection from ground? If so what's the best way to do that using the emitter boards available at the shoppe? I would like to use one of the QWAK low dome emitters that are also available at the Shoppe but their slugs need to be isolated from ground too (yet still transfer heat to the emitter board). Any suggestions?

If I go with the Wizard2 board how long will I have to wait? /ubbthreads/images/graemlins/smile.gif Wayne, any idea whether it will be a single-sided board and whether LED- needs to be isolated from ground?

Any and all suggestions are greatly appreciated! /ubbthreads/images/graemlins/help.gif

Jon

 

[dat2zip]

The Downboy, Wizard and Wiz2 are not sandwichable using the connectors and the emitter board. The Badboy and Madmax are the two that are directly compatible.

The downboy with some care can be made into a Sandwich using the converter board and the emitter board since it has the battery anode contact on the backside. You would have to wire the converter board to the emitter board and provide the appropriate spacing between the two boards with epoxy or something.

If the 14500 is a regular Li-ion and full charge is 4.2V then a resistored DD sandwich might be a good choice.

The Wizard2 coming out in could be made into a sandwich. It too would need a new emitter board or wired and epoxied together to make the sandwich.

I just got the prototype raw boards yesterday and another batch of ICs. Just built one. It's looking good. The next step is to make a run of them. That's TBD and still at least a month away. I do have part shortages and will only be able to build a limited number till ??? 20 weeks from now. That's the current forecast for one of the parts. Bummer. /ubbthreads/images/graemlins/frown.gif

Wayne

 

[flashlight]

20 weeks??? /ubbthreads/images/graemlins/confused.gif /ubbthreads/images/graemlins/crazy.gif

 

[StoneDog]

Wayne, thanks for the quick respons - sorry to hear about the parts shortage. The Wiz2 board sounds very exciting, I can't wait until they're available.

Were I to use a downboy and an emitter board are there any special precautions to keep LED- isolated from ground?

Jon

 

[TrueBlue]

Here is a picture Wiz2 750 Sandwich that I made for a single AA-sized MicroMag. The Wiz2 is sitting next to a Madmax Lite Sandwich. The Micro runs a 14500 3.7-volt rechargeable Li-ion cell. I made the emitter holder from left over parts from an Xnova AA light- the Xnova board had the 5mm leds removed then I inverted the board so the printed circuit side became the heat sink path to the MicroMag body.

The finished Wiz2 Sandwich could have been shorter. It looked so short I felt the need to raise the emitter board. In other words the Wiz2 doesn't take much room- it is very compact.

 

[tvodrd]

Haveblue,

I have concern for the life of your LED driven at 750 mA with the heatsinking pictured. The stock sandwiches rely on the emitter board's copper surface to transfer the heat from the LS's slug to the minimag body. Some of us go as far as to make copper discs to serve as emitter boards. /ubbthreads/images/graemlins/icon3.gif

Larry

 

[TrueBlue]

80% of the board is copper. I've had no problem with them at all.

Obviously you have a much better Wiz2 Sandwich than my pathetic Sandwich so I'll just pull my picture and let you put your better Wiz2 Sandwich picture in its place.

No harm done, OK?