telemonster
Contributor
This is a bit of work in progress. As I prepare to head on a dive trip with some friends from the laser show system community I'm going to (hopefully) convert a cheap underwater flashlight into a green pointer.
I found two existing units on the market. One is fairly expensive at $100, and it's unknown if it can be turned up or converted to run other modules. The other is a simple double A plastic pen pointer at Leisure Pro (and direct from China.) It looked like it might be an easy unit to convert but eh...
I chose a cheap metal light for the "host" that I found on eBay. It uses a standard 18650 battery and via ebay listing appeared to have some room where the reflector is. Also, the review indicated that maybe they have been underwater and didn't instantly flood, so maybe it will last at lease a few dives ;-) These are one of the many Chinese units that are all over the market.
The laser diode module which is still in shipping is a simple 100mw 532nm green with a driver rated for 3.7v. Duty cycle is noted at 1 minute on with some seconds off -- which doesn't instill confidence but YOLO. It would be nice to move up to the 200mw to 400mw range but I don't want to risk that kind of module on the project. I have some 1 watt blue laser diodes on the shelf but don't have drivers for them. Hmmmm.
The lights showed up early, so the first step is disassembly. The top part containing the reflector unscrewed without too much issue, and I'm working to get the rest out. Interesting on this light is that it is not activated by screw down of the head or pushbutton -- it has a settings ring. It looks like (so far) the settings ring moves a magnet around and that changes the modes. If this is indeed the case, that is pretty cool (until the magnet rusts out -- of course.) I expect to find hall-effect sensors inside or something, we will see. Cool for the light, but a bit more of a PITA for my project since I need to remove the existing LED driver electronics. I am still working on removing the existing electronics to make way for the new laser diode and driver.
I will post pics as progress happens. This is actually my 2nd underwater laser project, the first is one that uses a motor and a microcontroller to do PWM projecting various circle patterns out of an older Underwater Kinetics fixture that was meant for a 6v lantern battery. It will go on the trip as well, and it should actually produce "moon tunnels" and such for some interesting pictures. I went to test it over the summer at the local quarry (Lake Phoenix) and unfortunately the o ring to seal the unit was missing. I ordered a new O ring then found the one that was missing, so this should also finally make a voyage.
NOTE - the power output of this unit is above that which is eye safe as advised by the CDRH/FDA, and it will be used in a safe manner. Direct exposure of the exiting beam by people or animals would be bad.
Current pic of the housing (one together, one apart):
I found two existing units on the market. One is fairly expensive at $100, and it's unknown if it can be turned up or converted to run other modules. The other is a simple double A plastic pen pointer at Leisure Pro (and direct from China.) It looked like it might be an easy unit to convert but eh...
I chose a cheap metal light for the "host" that I found on eBay. It uses a standard 18650 battery and via ebay listing appeared to have some room where the reflector is. Also, the review indicated that maybe they have been underwater and didn't instantly flood, so maybe it will last at lease a few dives ;-) These are one of the many Chinese units that are all over the market.
The laser diode module which is still in shipping is a simple 100mw 532nm green with a driver rated for 3.7v. Duty cycle is noted at 1 minute on with some seconds off -- which doesn't instill confidence but YOLO. It would be nice to move up to the 200mw to 400mw range but I don't want to risk that kind of module on the project. I have some 1 watt blue laser diodes on the shelf but don't have drivers for them. Hmmmm.
The lights showed up early, so the first step is disassembly. The top part containing the reflector unscrewed without too much issue, and I'm working to get the rest out. Interesting on this light is that it is not activated by screw down of the head or pushbutton -- it has a settings ring. It looks like (so far) the settings ring moves a magnet around and that changes the modes. If this is indeed the case, that is pretty cool (until the magnet rusts out -- of course.) I expect to find hall-effect sensors inside or something, we will see. Cool for the light, but a bit more of a PITA for my project since I need to remove the existing LED driver electronics. I am still working on removing the existing electronics to make way for the new laser diode and driver.
I will post pics as progress happens. This is actually my 2nd underwater laser project, the first is one that uses a motor and a microcontroller to do PWM projecting various circle patterns out of an older Underwater Kinetics fixture that was meant for a 6v lantern battery. It will go on the trip as well, and it should actually produce "moon tunnels" and such for some interesting pictures. I went to test it over the summer at the local quarry (Lake Phoenix) and unfortunately the o ring to seal the unit was missing. I ordered a new O ring then found the one that was missing, so this should also finally make a voyage.
NOTE - the power output of this unit is above that which is eye safe as advised by the CDRH/FDA, and it will be used in a safe manner. Direct exposure of the exiting beam by people or animals would be bad.
Current pic of the housing (one together, one apart):