Help/info with problematic led swap

[KarlH]

Did I destroy a driver or am I just stupid, or even both.... I just swapped led's out from a d36 drop in with Cree XRE r2 which at the taicap was using 40 ma on low, 240 ma on medium, and 800 ma on high. I had an IR d26 drop in from solarforce which had more spill than throw and was useless at less than 100 yards because it created way too much light. I thought I'd try my hand at taking the led from that and putting it on a d36 drop in from Lumens Factory. The solarforce d26 pill pulled 1100 ma at the tailcap so I gave it a try. The good news is it works, the bad news is there are no longer a low-med-high and at the tailcap it pulls 2.5 amps. I thought if I screwed up I would have simply destroyed the led or the driver. Any ideas?

 

[Gunner12]

The modes are done in the driver, not the LED. So swapping the LEDs would not swap the modes.

It was an IR LED drop-in? IR LEDs run at lower voltages then white LEDs, which could explain the difference in battery draw.

If you want the beam pattern and modes, either swap the reflector if the threads are compatible, or swap both the LED and driver.

 

[KarlH]

I know the modes are the driver, but there is no mode anymore, just extremely high. It is far far far brighter than the 1 amp draw when it was on the solarforce drop in. Being current regulated, the driver from lumens factory should not be drawing that much from the batteries. As far as the voltage forward of the IR led only 1.7, that is not really an isssue. I have a d26 drop in from nailbender that is IR, but it is 940nm and is only good to 175 yards max due to 3rd gen night vision limitations at that high of IR frequency. According to nailbender, he uses the exact same drivers for the IR led's as he does for his white led's. And it definetely works, his two mode draws 110 ma on low and 1000ma on high. So the question is, did I fry the driver in my lumens factory drop in, or is there another possible explanation for the loss of modes and the extremelly high current draw?

 

[Gunner12]

I'm not sure what batteries you are using, but if it is drawing 2.5 amp and the drop-in is a lot brighter, it does sound like the driver is fried and the LED is in direct drive.

 

[KarlH]

Batteries are 2 primaries, duracell 123's, maybe 3 or 4 minutes run time on them at most.

 

[Gunner12]

The LED might be directly driven, which will explain the high current draw and output.

I'd suggest getting another driver and swapping that in.

 

[KarlH]

Just got home from work and was checking it out again. I pulled the emitter off of the pill leaving it soldered to the wires from the driver, and looking with a magnifer, there was some slight cracking of the wire insulation on the negative side. I could not see it with my naked eye, damn old age. The driver is apparently ok, as is the emitter. It will cycle through modes, although pulling about half the current at each level compared to what it originally drew at the tailcap with the original emitter(possibly damaged the driver but it still works?). So I had a short on one of the wires putting it in direct drive apparently.

 

[KarlH]

Next question. I broke the fine negative wire too short to solder it back onto the emitter and now have to get the driver out of the pill. Any suggestions on desoldering the drive from the pill so I can solder a new wire on without destroying the driver completely? Or perhaps use a dremel and cut the 3 points the driver is soldered into the pill? Any suggestions at all would be appreciated.

 

[Gunner12]

Use solder wick to take away the solder connecting the driver to the pill, then desolder the LED from the driver and you should be able to take the driver off.

I'm a bit confused at you first post. So you swapped the XR-E for an IR LED? If yes, then that could explain the lower current draw. As you know the IR LED does have a lower Vf.

The LED might have been damaged by the direct drive.