Product is no longer produced.
Sales thread:
Useful links:
https://budgetlightforum.com/t/-/33706
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 : https://budgetlightforum.com/t/-/33706?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: Rmoon=(Vbatt - Vled)/Imoon
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 (Vbatt - Vled) 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 Vled 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:)
