Lighting a 70-P Compass

[Ben Fuller]

Am looking for a solution to lighting athe now seemingly ubiquitous 70-P compass. There is a factory add on but seemingly not available on this side of the pond.

I can tape on cylume sticks but that is kind of boring.

So I have been experimenting with red LED's. These are the marine kind, sealed. Have altered the 3 LED kind, sold as a step light,so that all three shine straight. It fits snugly in the grove of a 10 inch hatch Run with 9 or 6 volts there is glare. What seems better is lighting the top at the rear, with either the aforesaid triple, a single ( sold as an Accent light or or use one of the LED round indicator lights.

You'd bury the light in piece of minicell cut to the diameter of the compass. Piece of bungy to hold it in place. Run the wires to the fore hatch. They are pretty thin. Then to a watertight container for the batteries.

Has anyone actully done this? So that I don't have to reinvent?

And while playing around I realized that there were some scratches on the compass housing. Got out the toothpaste and polished them out, an old jeweler / watch chrystal trick.

[bob budd]

If you are ambitious you can investigate switching power supplies that operate from lower battery voltages. The plus side is that the light output is relatively constant throughout battery life. The minus side is that the light output is no longer an indicator of battery life. Several LED lanterns use this approach.

[Ben Fuller]

These are bulbs designed to run at 9-12; I have been running them at 6, 4 double A's in a radioshack holder. Keeps the number of battery types down.

[bob budd]

A switching supply can turn any DC voltage to another.

When you wire single or multiple batteries directly to a light bulb their voltage drains away and the light dims over time. A switcher maintains a constant voltage, and thus a constant brightness, until the voltage falls below that required to operate the supply. These supplies are typically 80% efficient so you get more battery life at a desired brightness of the lamp for a given battery or combination of batteries. Furthermore, you can operate from a single battery and generate a higher voltage, reducing the size of the lighting device. Multiple batteries tied directly to a lamp provide a simpler system at the expense of reduced battery life and disposal of more batteries.

An LED light with more than sufficient brightness using these methods can be built about 2x the diameter and 1.5x the length of a AA battery. If you Google about you will find similar devices that are larger, have more batteries, etc. for sale. YMAWMV(your mileage and waterproofedness may vary).

So what is "Caret Browsing", my cat just hit "F7" and Firefox wants to know if I want it?

[djlewis]

>So what is "Caret Browsing", my cat just hit "F7" and

>Firefox wants to know if I want it?

Ask your cat re browsing.

http://tinyurl.com/jbkbx

[Paul Sylvester]

How about wrapping a lightstick around it? Held in place with a thin copper wire?

[Ben Fuller]

Have done the lightstick bit. Solution lacks the elegance that I am seeking.

Best rig I had was a brunton 85 on a hatch with the light already built in. Had a plug in battery pack. It was 12 volts and I had to reduce it as it looked like a red ball moving through the night.