Product is no longer produced.

Sales thread:

http://budgetlightforum.com/node/39824

Useful links:

http://budgetlightforum.com/node/39673

LD-M2 is a high power version of LD-2 developed because of continuous demand for higher power drivers which could reliably drive new big emitters like MT-G2,XHP50,XHP70,and multiple XM-L2s,nichia 219C etc.

Idea was old as LD-1,and it's simple:put main source of heat-mosfet on separate board which could then dissipate that heat more easily.Last testing with mosfet on led mcpcb showed good results,much better than older idea of FR-4 with vias : http://budgetlightforum.com/node/39673?page=4#comment-809544

Disadvantage of that method is two separate boards,so stacking two boards was pretty logical solution.

LD-M2 has two boards,the bottom one is 1mm aluminum metal core pcb,70um copper,with MOSFET,NTC sensor,moonlight resistor and multicell support parts on it;the top one is basically LD-2 pcb without parts that are on bottom pcb.

Result is driver with identical features/specifications like LD-2 except that voltage,current and power dissipation ratings are higher.

Because of that,I will mention only differences compared to LD-2 specifications (you can find LD-2 full specification in LD-2 info thread):

• Input voltage: 2.8 - 19V (user must solder jumpers for proper operation,depending on number of cells in series)

• Output current on high: 6A or 12A, 4A - 20Amps possible by changing 0603 resistor

• Max. power dissipation: 15Watts@25C case temperature, 12Watts@60C case temperature

• NTC over temp. sensor,1S-4S cell support parts and moonlight parts are already soldered on MCPCB by default - no need for adding/changing any parts for 1S-4S cell operation,only jumpers soldering/desoldering

• less than 150uA of parasitic current in sleep mode for all 1S-4S settings (slightly lower than LD-2 with multicell parts)

• Only two thick and one thin wire is needed for complete connection (optional,two additional thin wires for e-switch)

• Two big solder pads on MCPCB for up to 16AWG wire support

• 1mm bottom alu metal core PCB with 70um copper - bottom is electrically isolated so it can be mounted directly on flashlight metal surface

• 25mm diameter,~5.5mm height

Moonlight resistor note:

Moonlight current set: R_moon=(V_batt - V_led)/I_moon

For 2S,3S and 4S configurations moonlight current will be 2,3 or 4 times higher if stock 154Ohm resistor is used! Upper equation is still valid,but because (V_batt - V_led) is 2,3 or 4 times higher,current is also higher for the same factor.To keep moonlight current at ~10mA in case of 2S,3S and 4S configurations,moonlight resistor should have next values:

1S - R~150 Ohm

2S - R~300 Ohm

3S - R~450Ohm

4S - R~600Ohm

As it can be seen from equation,current depends on battery voltage,so it will drop as battery voltage drops.Typical V_led values for high power white LEDs at very low currents are 2.6-2.7V.

Setting operating voltage: 1S-4S solder jumpers

Driver supports 1 to 4 Li-ion cells in series,and to ensure proper operation,some solder jumpers must be shorted,deepening on cell number:

1xcell  (1S) - jumper 1S soldered,others unsoldered

2xcells(2S) - jumper 2S soldered,others unsoldered

3xcells(3S) - jumper 2S and 3S soldered,others unsoldered

4xcells(4S) - jumper 2S, 3S and 4S soldered,others unsoldered

Note: driver comes with all solder jumpers unsoldered,so user must solder jumpers depending on his application.

Warning!

Driver configured for "N" cell operation should not be used with "N+1" cells!

Driver cannot protect itself from too high voltage,so it will burn if it’s connected to higher number of cells in series in that case.

Connection diagram:

Diagram made by BLF member Andi,thanks!

Example:

Applications:

• driving single or multiple emitters  - XM-L2,XP-l,XP-G2,Nichia 219C,MT-G2,XHP50,XHP70,big color leds like SST-90,etc. in bigger flashlights (well in every flashlight with place for 25mm driver:)