CONSTRUCTION OF THE LAMP
After being scared off by the high prices of off-the-shelf diving lamps, I decided to try building my own lamp.I started to look around and found different web sites with tips concerning diving lamps, for example Reinhard Kopas Scuba do it yourself, and How I built my own diving light by Roger, and Home Page by Alberto Pace (in French). Before you begin building your own lamp you may find it helpful to browse some of their pages.
Här finns en svensk version!
CIRCUITS
Click on the pictures to see detailed versions
CIRCUITS
The circuit controls the two lamps that can be lit independently. When the battery voltage drops below a certain level the lamp begin to blink, providing a warning. The lamp are turned off automatically if the voltage drops even further. Circuit diagrams of the system are available in wmf format, Uw21.zip (12k). If you would only like one lamp, see Uw21_1l.zip (9k). The circuits described on this page were designed by Reinard Kopa.
One can also remove the electronics and use a relay or a simple little circuit capable of switching 4 to 5 amps with help of an FET such as the BUZ 11. For example, Uw3.zip.
To the index.
BULBS AND BATTERIES
 
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I use a 20 W spotlight and a 35 W flood light. I use lead-acid batteries because they are cheap and are not so sensitive to how they are charged. For these bulbs one should use a 3.2 A battery. The battery will be able to light the 20 W bulb for about 75 minutes, and the 35 W bulb for about 45 minutes. The drawback of lead-acid batteries is that they are heavy. An important point to consider is that lead-acid batteries release hydrogen gas which could explode. Therefore one should avoid keeping the battery in an enclosed area more than absolutely necessary. In contrast, nickle-metal-hydride batteries are lighter and do not release hydrogen, but they also cost an arm and a leg! :(. |
ON OFF SWITCH TO THE LAMP
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I have chosen to use a reedrelay to turn the lamp on and off. In this way one avoids a feedthrough for the switch which may leak. A socket head screw is welded on the inside, onto which is fastened a copper block with a magnet. To get the tin to sit in place a slot was milled into the back plate to guide the tip of the mating screw.
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LAMP HOUSING
The lamp housing is made of stainless steel. Stainless is a little heavier than aluminum, but it is easier to weld and it does not require surface treatments such as anodizing or painting. The back end of the tube is welded. The other end of the tube is welded to a flange similar to those used in vacuum systems.
ASSEMBLY OF THE LAMP
A special o-ring made of Viton is used to seal the tube to the plexiglass faceplate. The faceplate is held against the flange of the stainless steel housing by eight hex head screws. The battery, lamp and electronics are attached to a bolt that is screwed into the front edge of the tube.
To the index.
I have dived with the lamp to a depth of 9 meters without any leaks. The only problems I have seen are that the tongue element has leaked a couple of times, and the lamp weighs a little too much in the water (1 to 1.5 kilo). I have dived to a depth of 30 meters on severel occasions without any problems. The lamp is exceptional for diving in wrecks since one can switch between wide and narrow beams. If you have any comments or questions please contact me.
I would like to thank Matt Johnson for helping me with the translation.
To the diving page (in swedish).
Johan Thånell , last updated 2000-11-28 12:31:53