DIY Canister Light.

[Packhorse]

I made up a light using a mag light head and PVc tube for the battery box. I used two 2.2Ah SLAs. The main problem I get is with the toggle switch. It is a marine sealed switch with a rubber cover but it seems to have leaked. I packed it in my dive bag one time for a night dive. When I got to the dive site and unpacked my kit I found that water had shorted the switch which turned the light on and melted the plastic lens. since then I have relace the swich with another the same and filled the rubber boot with silicon sealer and also silicon sealer around the exterior of the switch. I havent use it much since and seems fine. I have thought of using a reed switch with a relay or mosfet but prefer a toggle.

 

[Firediver]

I used a regular marine boat toggle switch with rubber boot<by the same company>. YOu should always let the silicon cure a minimum of 24hrs.. Your Epoxy might of let if it's not the marine stuff.. it will break down in water.. I have problems with my lighthead flooding and that was the reason.... YOu can use a reed switch, and you can find them on e-bay..

I have the same idea light head as you being able to change the bulb and charge it through the same port.. so my top comes off and I am using a sealable o-ring.. When you go to put your LH back together, put some plumbers wrap on the threads.. should help seal the light.... How big is your o-ring your using???

 

[ShoalDiverSA]

Firediver,

Did you have any leaks through the switch/rubber boot combo? I am purchasing the same type of switch from a marine electrical supplier, and I would like to avoid drama...

Cheers,

Andrew

 

[ultravinnie]

get a hall effect sensor and drive a power mosfet.

all you need is a mechanical part OUTSIDE that moves a small magnet.

simple solution:
take a round piece of plastic ( from a rod ) and drill a hole through the centre. put a screw through, put a small o-ring over the screw and fasten this screw in the base of your lamp.
You now have a knob you can turn.
the oring sits inbetween the knob and the rest of the lamp.
the only function of the o ring is to act as 'spring' so the knob does not turn by itself ( the oring gives enough friction ).
its goal is NOT to make a seal.. there is no hole all the way throug.

in the bottom of thet round knob you drill a small hole ( not all the way through ) and you stick a small pellet magnet in there ( go to staples or officedepot and get the magnets for whiteboards )

the hall element is powered form the battery ( the current it takes is very small. ) its output drives a powermos that switches thelamp.

since there are no feedthroughs there is no risk of leakage. and it'll never break mechanically.

if you make the entire thing out of delrin it'll stand the test of time as well.

 

[airsix]

...and remember that the hall sensor is pole specific. If you glue your magnet in with the wrong pole facing the sensor it won't work.

-Ben M.

 

[Kwbyron]

OK, so lense cap is definately the source(even if my home-made boot fails, the inside is filled with silicon)water traveled along the cable into the battery pack. What I think is happening is that the oring between the main lense and the top of the threads is not giving a good seal and preventing the oring at the base of the threads from making a goodseal with the lense cap. I am going to pull the inner o-ring, and rely on the outer one. I think I might also put a bead of silicon at the very base of the tread to act like a second o-ring, then tape the threads. Think that'll work?

 

[TomP]

get a hall effect sensor and drive a power mosfet.

great idea. i know a little about haloclines & misfits but nothing about hall effects and mosfets. can you list any suppliers/part numbers.

thinking of using a slide and putting the switch in the light head. if and when i ever get started

 

[Firediver]

ShoalDiverSA: No I haven't had a leak at the boot. however be careful in you construction of the light that you don't accidentally puncture it. A guy I know spent quite a bit on his light and battery pack<it's DIY made from delron> and he had a pin hole in his boot. Out of three lights I have made, I have never had a leak.


Kwbryon: I don't think you should have a problem with your changes. I suggest you do a bucket test before you take the light out again. I still have two orings the origional small one that came with the maglight at the bottom of the threads, then i put a larger o-ring in the top with the second piece of glass...., My first DIY I only used one lense and only had a pin hole leak at the lense, having the same as yours....<hope I am making sense here lol> The pin hole was because I had used regular epoxy and it broke down in the water. I haven't had the problem of water going through the wire casing...............

 

[Kwbyron]

I'll give that a try, I made the adjustments mentioned above, and thought I would give it a test before filling it with electronics......well, at 60-70' the lense gave way... I am thinking that the glass would have normally been supported by the bulb as well... or it might not have been thick enough.

 

[diverryan]

I have just completed my light. It was leak tested and not one drop was found inside. This project could not have been done without Padipro's assistance. Thank you very much. As bulbs go, I have ordered 2 halogen bulbs.....one 6500K 50W (12 degree spot) and one 5300 35W (36 degree flood). I will let you know how well they work.