Source for Dual Power Level Converter

[Donald1800]

Does anyone know of a source for a LED Buck or Buck/Boost converter/driver that will output a low power 330ma or a high power 990ma/1A, depending on one of two power switch positions? It would seem most practical if the converter/driver was controlled by an inexpensive MicroP or programmable logic chip. It would be most convenient if the current levels were determined/user selected by two sets of 10 logic inputs connected (hardwired on a PC brd.) logically to ground or power, using binary numbers starting at 1ma with (1ma resolution/increment) to 1,023ma (1.023A).

Each switch position could be hardwired to one of two 'Power Select' logic inputs as well as each switch position connected through a forward biased isolation diode to the single converter power input.

If no one has this yet, is there someone interested in doing this design?

Donald

 

[Gnufsh]

Look at the drivers made by georges80, especially the nflex. I think his site is taskled.com.

 

[Donald1800]

Thank you for the suggestion, but a regulator with a single output current user selected from several available through a computer is not what I am looking for. I need a current regulator with two seperate output currents selected by an 'OFF/ON/ON' switch with the regulator/driver feeding one SSC P4 LED from 4 'D' cells, with the regulator/driver power input connected to the switch positions via seperate isolation diodes. This wiring allows the regulator power input to see an OR function for input power (ON1 OR ON2) and the Power Select logic inputs see only their respective and seperate power level selected switch positions (ON1 and NOT ON2, ON2 and NOT ON1).

This does not seem to be a difficult modification/variation of current designs. Someone out there should have already done this - if not, they should. This design allows for both max. brightness when needed and optimum battery life otherwise.

It should also be made available as a kit with the 'OFF/ON/ON' switch. And, as a kit, it should be user configurable WITHOUT the need for a computer. Simply provide two sets of user jumper selectable 10 bit binary number inputs (1ma to 1,023ma) for the low and high power selection. This allows an unlimited 1ma resolution from 1ma to 1.023A. A less desirable but using much less pins is a design with two 3 bit logic inputs allowing 7 descreet current levels from 350 - 650ma on the low power setting and 700ma - 1A on the high power setting.

This design will allow non-electronic/computer geeks to mod their own flashlights AND allow custom makers a straight forward option to upgrade their offerings - especially those STILL using direct drive in their flashlights.

Donald

 

[Donald1800]

I am so surprised that even with over 100 views, no one has a source recommendation - nor has a source stepped forward with interest in building this. What am I missing here? It appears SOOOO obvious!

Donald

 

[TMorita]

I am so surprised that even with over 100 views, no one has a source recommendation - nor has a source stepped forward with interest in building this. What am I missing here? It appears SOOOO obvious!

Donald

You're missing that you can do this with two separate converters.

Toshi

 

[Gunner12]

It might be possible to get a two stage switch like the Lumapower M1's switch, it uses a resistor for low and a full circuit for high.

 

[roverjohn]

If you are going to use a 4d mag as a host would'nt it be possible to just put a resistor and an on/on switch into the tailcap of the Mag. I know there would be two switches, and that I'm a ME not an EE, and also that I'm a total noob but wouldn't that give you two levels?

 

[Donald1800]

Yes, it is obvious that I could use several converters, which has the additional advantage of redundancy and disadvantage of complexity. And I may have to use this approach. However, I prefer the design I submitted if I can find one or stimulate an interest.

The other suggestions regarding special switches and resistors is really just the old, archiac Direct Drive (DD) technique used before we had converters/drivers. The major disadvantage to Direct Drive is the noticable reduction of light over battery life, even with NiMh which is still better than Alkaline. This issue will become even more apparent as LED structure improves (such as the SSC P4) resulting in very steep If vs. Vf LED curves, which translates into a very sensitive current variation (and light output) with a small voltage change. Constant current Buck or Buck/Boost converters/drivers will be the preferred method of powering state-of-the-art LEDs now and in the future. Why not a dual drive design which allows both maximum light output AND maximum battery life depending on the user's needs?

Donald1800