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That's 80mW - I hate auto correct 
Anyways, a couple months ago I ordered a bare 80mW diode module from E-bay with the intent on replacing a dead one in one of my laser projectors, or just mess with it. I'd have to dig up the link, but it seemed no different than the jillions of other ones for sale. Got busy on other things.
Today I decided to put it to a bit of a thermal test,and am scratching my head at the results. Or, is it common knowledge and I'm just ignorant.
I wired the module into a 5v switched source, and it fired up just fine. After about a minute the beam started to dim a bit. However, the beam coninued to drop slowly to about 60% of it's initial intensity (guessing by eyeball) and then stabilized. At that point (about 2minutes) I unplugged it because without a heat sink the brass was getting decently warm. No surprises here?
I then dropped the module into a small but decent 12mm copper heatsink. Nothing grandiose, but should give me a much longer runtime. Oddly, when I fired things up again the time frame and dimming was pretty much the same.
On a whim I pulled the heat sink off, and pointed a 60mm 12volt fan at the entire module, incuding the heat sink jutting out the back. This time the laser *did not* reduce intensity, and even after an hour was blazing away just fine.
Am I to conclude from this that the problem was the driver heating up and not the actual diode? If so, was it because 5v presented too much voltage differential that had to be converted to heat, or is something else going on worth chatting about.
Anyways, a couple months ago I ordered a bare 80mW diode module from E-bay with the intent on replacing a dead one in one of my laser projectors, or just mess with it. I'd have to dig up the link, but it seemed no different than the jillions of other ones for sale. Got busy on other things.Today I decided to put it to a bit of a thermal test,and am scratching my head at the results. Or, is it common knowledge and I'm just ignorant.
I wired the module into a 5v switched source, and it fired up just fine. After about a minute the beam started to dim a bit. However, the beam coninued to drop slowly to about 60% of it's initial intensity (guessing by eyeball) and then stabilized. At that point (about 2minutes) I unplugged it because without a heat sink the brass was getting decently warm. No surprises here?
I then dropped the module into a small but decent 12mm copper heatsink. Nothing grandiose, but should give me a much longer runtime. Oddly, when I fired things up again the time frame and dimming was pretty much the same.
On a whim I pulled the heat sink off, and pointed a 60mm 12volt fan at the entire module, incuding the heat sink jutting out the back. This time the laser *did not* reduce intensity, and even after an hour was blazing away just fine.
Am I to conclude from this that the problem was the driver heating up and not the actual diode? If so, was it because 5v presented too much voltage differential that had to be converted to heat, or is something else going on worth chatting about.
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