billg519
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- Feb 21, 2008
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Well, yesterday was a very rainy day where I am, so I decided to make a handheld IR laser (my third). My previous IR handhelds, both 808 nm, 1 and 2 watt, were based on 2 x 18650 battery power, current regulation by LM338. This time, I wanted to produce a much smaller laser, but still get about 2 watts of 808 nm output, so I made some design changes. I used 1 x 18650 battery power, and I got creative on the current regulator. I had purchased from DX some 350ma and 1050ma 7135 based flashlight regulators a while back, and had many left over. Current regulators can be parallelled for more current. I made a compact stack of 2 of the 1050 ma and 1 of the 350 ma. Testing the result showed that a current of 2.65 a would be delivered to my diode. Since my diode is rated 2.8 a maximum, I figured that this would be safe. I went to my machine shop and made a machined aluminum host and matching c-mount heatsink enclosure with focusable optics. I went with positive ground as the c-mount diodes are also positive ground. The 7135's are a negative side regulator, so this works perfectly with a positive ground system. The resulting laser is not much bigger than the red DX200, photo attached shows my new IR next to the DX200 red.
Summary :
Power 1 x 18650 Lithium Battery (DX)
Diode 808 nm c-mount 2.0 watt (from ebay - snoctony) in custom machined mount
Regulator Stack of 3 DX flashlight regulators 2 x 1050ma + 1 x 350ma
Host Custom machined from aluminum stock
Lens Aixiz glass lens was cemented into my own brass threaded focuser
Results :
I am extremely happy with this laser! It is quite small, has a solid feel to it, and looks good. Output seems quite strong although I have no method currently to measure a laser over 120mw. This laser lights a candle nearly instantly. Electric tape usually catches fire when being cut. A black plastic film can is instantly perforated. Matches light instantly. Wood burning even on light colored wood is easy and quick. Of course, anyone making a unit like this should have appropriate goggles. This laser has enough aluminum to it that it does not heat up during use.
Summary :
Power 1 x 18650 Lithium Battery (DX)
Diode 808 nm c-mount 2.0 watt (from ebay - snoctony) in custom machined mount
Regulator Stack of 3 DX flashlight regulators 2 x 1050ma + 1 x 350ma
Host Custom machined from aluminum stock
Lens Aixiz glass lens was cemented into my own brass threaded focuser
Results :
I am extremely happy with this laser! It is quite small, has a solid feel to it, and looks good. Output seems quite strong although I have no method currently to measure a laser over 120mw. This laser lights a candle nearly instantly. Electric tape usually catches fire when being cut. A black plastic film can is instantly perforated. Matches light instantly. Wood burning even on light colored wood is easy and quick. Of course, anyone making a unit like this should have appropriate goggles. This laser has enough aluminum to it that it does not heat up during use.