DIR GUE and backup lights

[CompuDude]

Properly configured, the canister light switch is turned "on" by pushing back and backup lights (if anything) hold the switch closed not open. Some canister lights may have the switch installed backwards. I also see divers putting the lid on in reverse fairly frequently. Traditionally the cord goes on the outside to avoid line traps. Some of the newer recessed switch lids may avoid the line traps but sill need to have the switch oriented correctly to avoid the backup light conflict.

You really don't need all those backups, nevermind the bungie loop modifications to manage them.

As your body moves around, the light head (when it's the wrong length) moves back and forth across the top of the canister light. On, off, on, off... Orientation of the switch is pretty irrelevant in that case. Regardless, though, I do put the cord to the outside on mine, as you describe. Frankly, reversing that and moving the switch farther from my body would probably eliminate that particular problem, but again, I don't have it with longer PT (or with the super-short Intova Compact) so it's really not a problem for me that requires changing a thing.

I certainly need ONE backup, since I dive at night a LOT. I feel better with two, and have one to hand off to buddies who are not as well-equipped. And if my wife ever allows me to enter a cave, I won't need to change my configuration from what I'm used to.

Btw: I only use the bungee loop mod on occasion, as the whim strikes me. I can easily unclip my backups with or without them. I posted the photo in response to a poster who was having a specific issue I thought they MIGHT be helpful to manage.

 

[laurin]

Having had a backup light turn off my primary twice during a dive (inside a wreck, at 39m) I've been following this thread with some interest. A shorter backup might have helped there.

Since most of my lights are DIY's or otherwise Frankenrigged or modified I have some experience with different switches and lid configurations. I used to prefer the toggle switches to magnetic ones (that tend to be favored by DIY guys around here), mostly due to simplicity (at least observed) and the fact that I've yet to see a failed one.

However, lately I've been testing a magnet-reed-FET (BUZ11) combination, and have started to convert most of my lights to that config. Mostly for the following reasons:
-the reed-FET-combo is actually more reliable and simpler than a toggle switch (if you consider them as electrical components)
-one less penetration to the canister
-dead easy to build; a reed, FET and resistor, some solder; and the whole bunch can be wrapped in heat shrink/glue/epoxy/whatever for additional waterproofing
-really small if built smart; nice if you're low on lid real estate, and can actually be fitted in the light head easily, too
-the magnet movement on the lid can be just about anything; a rotary movement is probably easiest to build and can't be switched off by a backup light

A reed+relay is a different beast (as seen in Gavin scooters, for example) and shouldn't be mixed with a FET arrangement. I've seen an overdriven 250W halogen video light can explode during a dive. Tortured cells -> hydrogen + a relay spark -> BOOM. This was during deco, and the diver was lucky to have quick enough reflexes so he managed to catch the falling battery pack as the can was a couple kilos negative. Need to get the video online sometime. :cool3:

Also, I've tried the bungee rigging for backups now on one dive, not because I feel that I particularly need one, but because I like to try out new stuff. They do seem make picking up and dropping stages/deco cans just a tad faster, and I don't see how they could possibly be a problem when deploying the backup. So they'll be staying on my harness, at least for now, more dives needed for a final judgment.

//LN

 

[Chous]

For me - i don't want to use light with CR123. As far as i know they are made
by lithium technology. Is it good if i'll dive in cold water? I think
no...
And also, for example in Russia, CR123 is much more expensive than AAA
or AA type. I can buy AA or AAA in every fuel station or supermarket
all over the world, CR123 only in photographic supplies store.

 

[rjack321]

For me - i don't want to use light with CR123. As far as i know they are made
by lithium technology. Is it good if i'll dive in cold water? I think
no...
And also, for example in Russia, CR123 is much more expensive than AAA
or AA type. I can buy AA or AAA in every fuel station or supermarket
all over the world, CR123 only in photographic supplies store.

Lithiums are actually more tolerant of cold than alkalines, but either will be more than adequate if fresh.

 

[CompuDude]

For me - i don't want to use light with CR123. As far as i know they are made
by lithium technology. Is it good if i'll dive in cold water? I think
no...
And also, for example in Russia, CR123 is much more expensive than AAA
or AA type. I can buy AA or AAA in every fuel station or supermarket
all over the world, CR123 only in photographic supplies store.

I agree with your reluctance to buy a light with cr123 batteries, for reasons of battery cost and availability. Cold isn't really a factor, however, and the shelf life of cr123 blows away the shelf life of Alkalines. Cold is a problem for all battery technologies, but as rjack pointed out, cr123's do not have a problem in this regard that's any worse than others.

I would still rather use AA or AAA batteries, however, which are far less costly and far more readily available worldwide.

 

[Chous]

...I would still rather use AA or AAA batteries, however, which are far less costly and far more readily available worldwide.

I just want to buy Intova torch, but in shop only CR123 version. AAA version will be available in February 2010 and will be more expensive.
So i don't know what to do. Order CR123 version or wait AAA and pay more money...

And for example one piece CR123 in Russia cost aprox. $6 and pack of 2 AAA cost $2. 6 times more cheaper...

 

[CompuDude]

I just want to buy Intova torch, but in shop only CR123 version. AAA version will be available in February 2010 and will be more expensive.
So i don't know what to do. Order CR123 version or wait AAA and pay more money...

And for example one piece CR123 in Russia cost aprox. $6 and pack of 2 AAA cost $2. 6 times more cheaper...

To be completely fair, however, I'm not sure the 3 C-cell Scout-style lights and the Intova Compact (the only one I'm aware of that takes AAA batteries) are comparable, or really intended for the same purpose.

I'd consider taking a current-build Intova wide/narrow on a technical dive... but not the Compact. The burn time doesn't fall within the parameters I look for on the Compact, and the rear-mounted switch has yet to prove itself over time, since it's only been on the market for about 6 months, if that. (The early model magnetic switches on the Intova wide/narrow models reported some problems, but I understand they've been worked out and currently-shipping pieces should be no problem, based on the number of people actively using them in caves.)

For open water, the Intova compact is a nice little light, however, and it makes a great loaner... and it uses the readily-available and inexpensive AAA batteries.

 

[Chous]

For open water, the Intova compact is a nice little light, however, and it makes a great loaner... and it uses the readily-available and inexpensive AAA batteries.

Am i right you are talking about Intova LED 4.7W 130 Lumen Light or about another model of Intova?
https://www.divegearexpress.com/lights/backuplt.shtml

 

[b1gcountry]

I own both of those lights. They both seem like very nice lights, and very bright, but I'm not sure how much I like them for backups. I've activated both the switches accidentally with them just sitting in the bungees, and with gloves on in the dark, I can't find the slide switch on the CR123 version.

 

[Chous]

...with gloves on in the dark, I can't find the slide switch on the CR123 version.

I didn't think about it, thank you. I use SiTech DryGloves so i think there may be some problems with Intova. Do you think version with push button better in this case?