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2011-03-18

Light reading





So last week I met with Tim Mackinlay and his wife Bice down at my club for a coffee and a chat about the wonderful world of LEDs. Tim builds and sells LEDs of the "warm white" variety; they aren't your Dad's (elder sister's, maybe?) "bluey" LEDs, but are easy on the eyes and have the ideal (for boating) quality of directionality and low-amperage draws.

Tim was kind enough to give me a couple of "bayonet mount" lights and a foot-long strip of ganged LEDs to play with as an incentive to buy. Frankly, his prices are very good, so if the quality matches the ding, he'll be receiving my custom.

I've spoken about the logic of using LEDs before (or at least I think I have). For sailboaters, who are not making electricity when actually sailing, unless they have a wind generator or solar panels (and it's full daylight), lights are among the biggest users of the usually limited power that the boat's battery banks can store.

We are so used to more or less unlimited access in this country to cheap...but steadily getting more expensive...electricity that my constant shout of "turn off the lights when you leave a room" is frequently ignored and our cities at night are ablaze with clearly illuminated, empty rooms.
With the incandescent 12 VDC "auto lamps" in use aboard most boats until the last five to ten years, you simply cannot leave them on for hours on end without running the engine, and its amp-producing alternator to recharge the batteries any more than you can leave a car's headlights on all day and expect the engine to crank. They convert 90% of their draw to heat to make that little tungsten wire glow, and heat up the boat (desirably, in some situations) in the process. Rare is the boater who hasn't overdrawn his or her batteries through miscalculation or mistake, and it can make for a sick feeling when the engine won't start...or starts in a dodgy fashion...because you've left the lights on too long.

The heat issue was solved in part years back via the use of 12VDC flourescent tubes and "C-shaped bulbs" that provided either a cold or warmer light, but without the heat output. I think they drew a little less, as well. Good as area lights, like for under-counter fixtures in the galley or the head or even the engine room, the flourescents, if not well-made, sometimes had the habit of emitting RF interference, leading to crackling static on certain VHF or SSB frequencies. Some alternators do this, too. It's sometimes due to shielding or proximity issues, but can be annoying. Also, some people just don't like the "office lighting" effect aboard. Maybe it's the atavistic impulse that sailboats below deck should be bathed in the cheery yellow glow of stinking oil lamps or even candle-powered "lanthorns". Or maybe it's because the last place you want to be reminded of "the office" is "the sailboat". Whatever...flourescents have never taken off, except as work lights where the shadowless "throw" of the light is great for finding critical little pieces you've dropped under the engine.
Alchemy has a real mix of lighting: incandescent nav lights of the "honking" type, which in this case means 25 W Aquasignals. These are oversized from a legal standpoint, and draw down the batteries, but if I'm motorsailing at night, I love the fact that they make us the brightest thing for miles. LEDs here, at 1/10th of the draw, if equivalent in brightness, would represent a huge savings in amps, because I would sail with the trilight on all night without thinking I was going to have to turn off the fridge for three hours.

I also have two 10 w lightbulbs in the saloon bulkhead fixtures, tube and C-type flourescents in the galley, head and pilot berths, a typical brass and faceted glass incandescent in the aft cabin, 10W halogens for aft cabin berth reading lamps and an Alpenglow red and white flourescent in the pilot house. There's even a blue LED with a switch for the fridge! Throw in the various LED flashlights, head lamps and work lights I own, the oil lamp I bought from that poor girl who died on the S/V Picton Castle, and short of an arc lamp, it's all there: the history of boat lighting in one hull! It's quite representative of the changes since Alchemy was built and I'm sure many a boat in the harbour contains the same mongrel mix.

I would keep a halogen for close work in the galley, like dish washing and cutting board work, and maybe for the "workshop" forward, for when I have to do soldering with a magnifying glass or clean out burrs from tapping aluminum. I also will keep the Alpenglow, which by some design magic is the flourescent fixture that looks the least flourescent of any I've ever seen, and has "dim" settings in white and red suitable for the nerve center of the boat. The rest? Swap meet.

Going forward, the goal of "independence from the marina and its Satanic shore power" is intimately tied to the concept of installing and keeping topped up a substantial house battery bank (the batteries used to power everything but the engine starting, by far the biggest, if short in duration, use of electricity aboard and customarily delegated to a dedicated "start" battery). Then, once you've got this quarter-to-half ton of sparky lead at 100% capacity, the idea is to use it as little as possible! One pulls this particular rabbit from the confines of its top hat by monitoring and reducing draws where possible. The fridge gets insulated with tranches of blue or pink closed-cell foam, sealed with gooey, waterproof, condensation-blocking industrial goo, and strict rules about opening the lid are posted. The idea is that the compressor should cycle as little as possible, because in the tropics, the difference between keeping things frozen and the temperature on deck can be awesome to contemplate and expensive from an amps-consumed viewpoint to achieve.

Lights are also amp-eaters. LEDs, not so much. Leaving an LED on for 10 days tends to equal the equivalent of leaving a lightbulb of equivalent output on for one day, and even drunken sailors are likely to notice a lamp left burning that long. So the advent of more "warm" and "less directional" LEDs is welcome. I have "first gen" blueish LEDs I bought some seven years ago on Valiente already, and they aren't nice, but I can't measure their draw with a one decimal amp meter, so they'll stay because they make great night lights.

Where LEDs have real potential, I think, is not in the "bright, warm reading and area light" market, where I think the corner has been turned on everything but price (still too expensive!), but in specialized, boat-particular applications where the LEDs are dim, directional and not even attached to the boat's DC power supply.

Years back, I got from one of my favourite surplus stores a single dim, red "blinking" LED, a 9V battery and a 9V battery connector. Some electrical tape and two crimps later, I had a weird-looking black Pez dispenser-like thingie that blinked steadily like it knew something. I clamped it to Valiente's nav station and sure enough, through the smoked Lexan of the dropboards, it looked like some sort of burglar alarm or other security device. It worked for about 14 months straight before needing a fresh 9V, which set me back two bucks. Did it keep the boat safe? Dunno. Did I get two bucks' worth of "peace of mind"? Yes, I did.

So I started to think: What if you wired an IR sensor, some sort of auto-off circuitry and the same 9V battery and the same dim red LED to the companionway stairs? On the blackest night, a light would illuminate the companionway steps...poorly, so as to preserve precious night vision...and then would shut off after three seconds? You could have the whole boat done this way, although you'd want to have a "daylight shutdown" to save power. A heaving boat at night can be tricky, and yet turning on proper lights can disturb sleepers. How much better would it be to have invisible beams turn on dim "here's where the cabin sole is" lights that self-extinguished as you moved through the boat?

Another use, already implemented in part on Alchemy, are magnetically switched little LEDs that click on when a locker lid is raised or when a cabinet door is opened, throwing lights on the contents. I would like to implement this idea pretty well everywhere not only because it logically shortens the time spent rummaging around in the dark (there's that "do not disturb" aspect again), but is also a safety element, because on a rocking boat, you don't want to have one hand in the locker, the other holding a flashlight, and no hand left "for the boat". I've worn headlamps on watch and they are the next best thing, but paradoxically are sometimes too bright. "Dedicated" locker LEDs down in the bilge stowage and inside cabinets and lockers could save time and be safer when all about is dark...and at night at sea can be like the inside of a cow.

Another aspect of LED and safety concern is what happens when the normal lights go completely out. Electrical failures of the catastrophic sort are rare, true, but lighting happens, corrosion never sleeps and fuses inevitably blow, any of which could find you searching in the dark, on a lee shore, with heavy air all about, trying to connect batteries you know were good three hours ago to nav lights that may or may not be still functional. If you were the Pardeys, you'd already have the oil lamps out, but we aren't them, and maybe you aren't, either. You want perhaps, some form of lighting that is self-contained and independent of the boats "mains", as our British friends call it.

The "self-contained" part is critical. Any situation bad enough to need self-contained lights is probably going to involve a breakdown of the boat's electrics, either via water ingress or flooding. I know I'd want the bilge pumps to work then, not the lights. I don't need a light to notice my feet are wet.

There's a little kids' toy you can buy at any dollar store that is a tiny coloured LED worn on a little piece of elastic on one's finger. Like so:

I don't like single-use items, but these are cheaper than the batteries inside them and are great for dark corners.


Well, you could either mod them for a white LED, or simply use them as is on your little finger to bring light RIGHT UP to the work in your boat! Clip 'em to a hat and you've got a map reading light. At a buck a piece, you could buy quite a few to brighten various areas up to see if the concept of "many points of light" works for your boat.

That's what I mean is a bit of a paradigm shift with LEDs. They are so cheap and plentiful that you start thinking less of "what light" and more of "where would I want light?"

Of course, all these little gadgets can be coated or siliconed to make them more water resistant, if not water-proof.

That's enough for now. Good grief, I do prattle on.