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Recently there's been a bit of confusion about the RPL's auto shut off and what triggers it, so I tried to do some investigation. At first it was said to be to protect the laser from overheating, then Jack mentioned it having more to do with the batteries. Finally, someone (I think it was Aseras) mentioned getting longer runtimes with slightly used batteries. Well, it looks like they are all partially correct. Here's the situation as I understand it from the broken English:
The RPL auto shut-off is ultimately to combat the laser overheating, but it doesn't do this by a temperature sensor. As a laser diode heats up, it becomes less efficient and so the RPL circuit makes it draw more power to sustain output. Eventually it starts trying to draw more current than it was spec'd to, and that's when the auto cutoff triggers to shut down the laser temporarily.
How the actual driver circuit works on the RPL puzzles me, but I did learn that a fully charged battery results in both higher input and output powers for the diode/laser. Therefore, using a fully charged battery, or a higher capacity battery will cause the diode current to already be close to auto off levels, whereas letting the battery drain a little before use may allow unlimited runtimes.
I hope that helps all you RPL users.
PS: If you are considering an RPL, send me a PM as I may have some useful info for you.
PPS: I haven't had time to work on my site recently (Will be called A1 lasers and used for selling the random stuff that passes through my laser collection), but eventually I will get it online and be able to sell additional tailcaps to you RPL owners who would like to have both (I bought my RPL 300 with the adjustable endcap, and my RPL Blue 17mW with the non-adjustable endcap. I found I much prefer the non adjustable one, but I only have one of those endcaps for two lasers)
The RPL auto shut-off is ultimately to combat the laser overheating, but it doesn't do this by a temperature sensor. As a laser diode heats up, it becomes less efficient and so the RPL circuit makes it draw more power to sustain output. Eventually it starts trying to draw more current than it was spec'd to, and that's when the auto cutoff triggers to shut down the laser temporarily.
How the actual driver circuit works on the RPL puzzles me, but I did learn that a fully charged battery results in both higher input and output powers for the diode/laser. Therefore, using a fully charged battery, or a higher capacity battery will cause the diode current to already be close to auto off levels, whereas letting the battery drain a little before use may allow unlimited runtimes.
I hope that helps all you RPL users.
PS: If you are considering an RPL, send me a PM as I may have some useful info for you.
PPS: I haven't had time to work on my site recently (Will be called A1 lasers and used for selling the random stuff that passes through my laser collection), but eventually I will get it online and be able to sell additional tailcaps to you RPL owners who would like to have both (I bought my RPL 300 with the adjustable endcap, and my RPL Blue 17mW with the non-adjustable endcap. I found I much prefer the non adjustable one, but I only have one of those endcaps for two lasers)