Scram Bag: Head torch

Once in the dark you won’t be able to easily see what you’re doing. You may have a torch and have the option of holding it in one hand and attempting to do things but this may really get in your way. You may need both hands free. Of course you could hold the torch in you mouth or in the crook of you neck. A simpler solution? A head torch. A head torch frees up you hands an the light is always on the area you are looking at, a lot of problems solved.

A basic single unit head torch with overhead strap and 12 LEDs.

Head torches are basically divided into several categories:

Form factor:

Single strap: A single strap that encircles you head like an elastic headband. Minimalist but not as secure at  the over head strap and not appropriate with heavier lamps.

Over head strap: Like the single strap but with an additional strap that goes over your head to hold the lamp more firmly but at the expense of having to remove other head gear to put it on or take it off.

Single unit: the entire lamp batteries and switch are in one unit at the front.

Separate battery compartment: Batteries are separate to the lamp often at the back to counterbalance the weight of the lamp or possible to be worn on another part of clothing. external battery packs can get in the way and they is always the worry of the wire that connect to the lamp itself getting dislodged or damaged.

Lighting:

The lamps

White/white blue LED : One or more LED in the blue-white spectrum give of a diffuse glow of light extending about 5 meters. good enough to walk an night or fiddle with an object. A single LED can last for a hundred hours of operation for one battery charge.

Red LED: One or more LED in the red spectrum which allows you to intermittently use the LED occasionally without greatly affecting your night vision. Excellent for reading maps at night. Red light does not radiate far and is quite discrete at night, many animals can’t see red light- even at night.

Halogen / high lumen blub: One or more ultra bright focused beams that create a very strong cone of light stretching for 50 or more meters, great for looking at more distant objects at night. These lamps have a tendency to really drain batteries fast. In terms of battery life you are looking at 10-60 minutes of operation.

Ultra violet: I haven’t seen these on head torches yet but if you are a little electrically inclined you might consider adding one. Why? If you are in an area where there might be scorpions like Central Australia, you’ll find out that scorpions and some other insects actually glow under UV light. Pretty handy for avoiding a nasty sting.

Cree LED: Super bright with power consumption similar to a standard LED. The illumination is about 200 lumen ( the combined brightness of 200 candles) They are usually in a focus adjusting tube with a over the head strap configuration .Theses headlamps are new to the market and some are selling at very low prices, get in fast on these they are very good value for money.

Adult scorpions, cat urine and some spiders glow under UV light. http://www.science.widener.edu/~schultz/scorp/scorp.html

 

Power supply:

Batteries:

Commonly  AAA size batteries are used, sometimes because of the electronic switching involved, rechargeable batteries cant be used.

In higher light output head units CR 123 batteries are often used they are more  expensive, obscure and harder to find that other batteries.

Wind up: if this is the only power supply you will find winding up  a torch a lot gets a bit old really fast and as a consequence the batteries never really get a full charge. Investigate adding an alternative charging modification.

Solar: You will need to leave this in the sun a long time to get the charge required.

External charge plug: Great idea if it can be made waterproof perhaps with rubber cap or similar. Hopefully the charge plug is not really obscure in-case it gets lost.

The switch:

These seem to be more complex than needed. Often there are several light modes switching on various arrangements of LED’s or Lamps and may include a flashing feature. One torch i had had the annoying feature of refusing to respond when at low current forcing the torch into a stay on and go dead mode. the only way to avoid this was to take the batteries out to turn the lamp off.

Other important considerations. The head torch will need to be water resistant at least, preferably waterproof.

Cheap head torches can malfunction quite quickly. I bought two different ones recently that simply didn’t work at all, straight out of the box.

Best advice:

Single unit, using rechargeable batteries, at least 3 White LEDs, simple on/off switch.

Head torch  $15 and upwards depending on features.

 

OR

Cree LED because of brightness and battery life.

Repair: Examples – Small solar battery block in rain water

I have a bed side lamp I got from IKEA years ago, it’s solar powered with a removable block of batteries. So I did something dumb and inadvertently left the block out in the rain. Thinking the unit was well sealed as I retrieved it it made a sloshing sound, obviously not that well sealed. The 2 slots for the power output of the battery were it’s Achilles heel, and let the water straight in. As I unscrewed the block, water dribbled out of the screw hole, this repair/salvage job started looking dicey. The real risk was if there were complex charging circuits in the block. I finally opened it after almost losing 2 of the 4 screws bouncing on my wood floor.

Solar battery block with 3 x AA (1200mAh?)

After about 5 minutes of using a hair dryer to dry the water away, I discovered there was apparently only a fuse as the sole electronic component. Fuses do tend to survive water quite well.

Quite a relief really. Other things I found out were there were only 3 AA cells (I had guessed 4) and they were stamped with  1200A, I speculate that means 1200mAh, low on the capacity spectrum of rechargeable batteries.

The things you learn once you have the audacity to pop open the case.

Amazingly enough, once dry the unit worked.

Solar lamp in working order