Shedding light on PlayStation’s LEDs

To the editor:I just read your article on PlayStation (Issue No. 99, July/August 1999), Steve Fossett’s new catamaran designed by Morrelli and Melvin. It’s an interesting article, but it contains some errors that I think need correcting. While Davis Instruments is a licensee of my company (Deep Creek Design, Inc.), they had absolutely nothing to do with the design or construction of either the interior LED lighting or the LED navigation lights for PlayStation as might be inferred by the text of this article. Davis, to my knowledge, sells no navigation lights at all, apart from the “Mini-Mega” light series, and they rely on conventional incandescent bulbs and are not LED powered. Deep Creek Design, Inc., should be solely credited for the design and manufacture of PlayStation’s LED-based interior and navigation light “bulbs.” Davis Instruments does build and market under license to us, our original series of LED “cluster bulbs” that were featured in a recent article by Tim Queeney (“LED bulbs have a bright future,” Issue No. 91, July/August 1998). The Davis off-the-shelf versions of these bulbs are lower powered that the custom ones we did for PlayStation, which has a 24-volt electrical system. They do offer a very affordable opportunity for the energy-conscious sailor to retrofit many existing 12-volt lighting fixtures with the same LED technology used in Fossett’s boat in the interior lighting, but they are not designed for use as navigation lights. The custom-built navigation light replacement LED-based “bulbs” we built for PlayStation are used in existing off-the-shelf fixtures from Aqua-Signal. These bulbs represent state of the art in existing LED technology and contain far more advanced circuitry than employed in the simple Davis LED clusters. Our chief of engineering, Mr. Ken James, is wholly responsible for the unique pulse-drive circuit that powers all of PlayStation’s navigation lights, which are also bi-polar and fully RFI shielded. The pulse-drive circuit flashes the LED array on and off very rapidlyso fast that the human eye can see no flicker and the lights appear to be burning continuously even though they are only “on” half the time, hence conserving even more energy. Our bulbs led (no pun intended!) the way as PlayStation set the new 24-hour distance record. The navigation light fixtures themselves were damaged in the record run, but our LED-based bulbs “took the licking and kept on ticking” anyway. The same circuit design and reliability are now available in out own Star series of LED-based replacement bulbs. Our own testing reveals that our LED based “FirstStar” anchor light replacement bulb unofficially meets the two-mile visibility requirement for sailing vessels up to 20 meters LOA, when used in the bottom (anchor light) portion of existing tri-color masthead mounted fixtures from several manufacturers. But, they are not officially “certified” as navigation lights as yet. The FirstStar is not available from any source except from Deep Creek Design, Inc. At this time, I think we can lay claim to the most energy-efficient (50 milliamps), longest-lived (100,000 hours typical) anchor light source in existence that provides two-mile visibility when used in existing fixtures. The FirstStar anchor light replacement bulb is available now, and it is the direct result of R and D performed for and first employed by Gino Morrelli on Steve Fossett’s PlayStation.

By Ocean Navigator