Cheap 1.2 amp driver running off 2x 3.0v lifepo4 cells that iam using.

[Garoq]

Hello, my apologies to necro-post, but did you use any sort of capacitor to protect from voltage spikes?

Thanks,

AAlasers

There is a delay caused by a resistor/capacitor combination built into the driver circuit that allows the input voltage to settle and the regulator internal circuitry to start to function before the power is applied to the laser diode. This delay results in a relatively smooth turn on voltage being seen by the laser diode.

 

[flucero28]

with the proper current limiting resistor in place, say to limit the board to 470mA would it be possible to use this board with a LPC-826? Or is the voltage this board puts out too high for the LPC-826 without a diode in between the driver and laser diode?

 

[Blord]

The LPC-826 runs fine on these drivers. Use the formula 0.25/R=I for the proper resistor.
Also the diode must be isolated from the battery, no direct contact between these.

 

[flucero28]

I have one of these boards that I swapped the sense resistor value to .520hm, so I was seeing about 478mA with a 4v test load and 8.4v input (2x16340). After disconnecting power I Shorted the leads on the board as a pre-caution and Hooked up an LPC-826. After a few short duty cycles in an aurora c6 host the diode turned LED. Now that Blord confirms these boards just fine, I will have to verify all connections. Is there anything I may have missed?

 

[Blord]

Did you isolate the diode from the host/pill/battery ?

 

[flucero28]

The heat sink is bare aluminum, however the host is anodized so should not be conductive right?

 

[Blord]

The C6 host shouldn't conduct electricity but did you measure it with the DMM ? The anodizing process isn't always 100% perfect.

 

[flucero28]

Thanks very much blord! Upon close inspection discovered that the heat sink makes contact with the flashlight pill upon tightening the front bezel. Confirmed with DMM that the heat sink and diode were conducting ground via the housing and therefore overdriving the diode.

Edit: rep added Blord for your help troubleshooting