Date: Thu, 22 Oct 1998 03:01:15 -0400 (EDT) From: Marty Goodman MD KC6YKC Subject: Night Sun's "Trilight", revisited Today I had my first look at a commercial-issue, real, in the steel Night Sun "Tri-Light". Folks on BikeCurrent may recall my extolling the virtues of this product based only on a detailed description of its specifications and design characteristics supplied BY its designer (Tobin of Night Sun) AND on Zach Kaplan's description and impression of it when he saw a prototype of it at InterBike a month or so ago. NOW I finally had a chance to SEE and (albeit briefly) test out the thing myself. I'm delighted to say the Night Sun "Tri-Light" in almost every way lived up the extremely positive impression I'd gotten of it previously by second hand means. This unit is a finely CNC - machined module with three MR11 bulbs in a row. Each one can be independently aimed in any direction by about 15 degrees or so, by virtue of a ball and socket joint for each MR11 module. It APPEARS the tension on the ball and socket joints is such that it will both permit easy adjustment AND stay in position once adjusted, surviving bumps in the road, tho this aspect of it of course has to be further tested (I just tested it in a living room). The stock model is supplied with narrow 10 degree spot 8 and 20 watt MR11 units, and a wide angle 17 degree 12 watt MR11 unit. Tho any nominally 12 volt MR11 bulb can be installed in the lighting heads, and one option Night Sun offers is a 35 watt ultra high power bulb. The appearance of the unit is very rugged and professional. It looks to be "military / industrial grade". The control over the three bulbs is very well done: There's a small rectangular box with three push on / push off buttons (which have nice tactile feedback, and a reasonable travel distance, for good feedback to the user that they have been properly pressed). Each button has a different color LED above it (red, amber, and green), as further feedback to the rider on the status of the three headlamps. I found that if I put the low and high beam "out of phase" (one on, one off) I could instantly switch between low on / high off and low off / high on by just tapping the high and the low beam button at the same time with two extended fingers. Other combinations of light switching are equally easily accomplished. The lighting control module is at the end of a short stalk of wire attached to the main three light module. Of course, recumbent bicycle and tricycle riders will have to either order custom versions with a longer cord between the lights and the switch box, or engineer their own custom extention to the switch box. This isn't really a serious criticism: NO ONE really takes recumbent bikes and trikes into account when they design lighting systems, cycling computers, etc. We ALWAYS have to customize stuff, and stuff with electrical cords is no exception. The charger is VERY heavy duty. The DC power supply is a 24 volt 1.7 amp supply... FAR more powerful than any supplied with ANY other bicycle lighting system. It HAS to be powerful, to permit true SMART, FAST charging of the 4 amp hour NiMH battery. For smart charging involving detection of zero delta V requires a relatively high speed of charging. In this case, C/2.5 rate, or 2.5 hours to fully charge the battery. Most other bicycle lighting systems require 8 to 10 hours to fully charge a relatively completely discharged battery. The battery is a 13.2 volt 4 AH battery. Thus Night Sun, like NiteRider, Jet, and TurboCat (among others) "overvolts" its "12 volt" bulbs, to achieve greater efficiency and brightness, at the expense of decreased bulb life (a sensible, intelligent trade off, which still leaves a bulb life of around 500 to 1000 hours). Night Sun maintains, and my information would seem to support its contention, that NiMH batteries are extremely easily damaged by trickle chargers and other less than completely smart chargers. There seems a real possibility that the flood of new, high tech NiMH battery systems used in bike lighting systems will be plagued some months down the line by significantly decreased battery life due to improper charging. Night Sun believes its fast, smart charger, made to meet NiMH battery manufacturers' specifications, will not cause this problem. Night Sun has taken rather a big gamble by forcing the retail price of its product to be VERY high due to the inclusion of an expensive, fast, smart charger. For it requires a very educated public and dealership audience to understand WHY the extra money for such a charger is worth it. The only criticism I can make of the Tri-Light design now that I've had a chance to see a production model is that the mounting of the lighting head does not permit quick release, and is rather heavily geared toward mounting on handlebars, with a (rugged metal + injection molded plastic) strap mounting attachment grabbing the handlebars on either side of the stem. The Tri-Light is a top of the line incandescant (halogen) + NiMH battery system, costing over $350 retail. Its competition are other very expensive halogen systems, such as the NiteRider Digital Pro 12. The NiteRider Digital Pro 12 offers a number of fancy features implimented by its embedded microprocessor. SOME of those features are valuable (such as the warning then automatic cut off when the battery gets extremely low). Other features of the Digital Pro 12, such as the pulse width modulated / chopper dimmer function for lower power operation, are distinctively inferior to the approach to power husbanding provided by the Night Sun "TriLight", which uses the far more efficient approach of running all bulbs at full power (even a bit over-volted) and providing power control by using a lot of bulbs, each separately switched by the user. It appears the Tri-Light has a more sophisticated charger, too. And certainly a faster one. The TriLight should appeal to serious cycling commuters and police cyclists, who wish the most rugged of halogen lighting systems, and one that offers the widest variety of efficiently implimented different light levels. It would do best on a "commute" or "police" bike permanantly mounted to the bike (or trike). Randonee / Tinkerer musings: Thinking like a tinkerer, I could see a highly customized Tri-Light lighiting head that used 6 volt MR11 bulbs. Say, two 5.5 watt bulbs of the sort used in the SunSport, and one 10 or 15 watt bulb. Powered via one or two LVR2 PWM regulators, and rechargeable lithium, primary alkaline, or primary lithium batteries this would make a potentially superlative brevet / randonne system. Substitute a rechargeable NiCd or SLA battery, and you have a less expensive configuration for training and night commuting. Run one low power MR11 at 4 watts, one at 5.5 watts, and overvolt the 10 or 15 watt bulb just a bit, and you have a system which allows considerable husbanding of battery power during hill climbing and when riding under street lights, considerable redundancy of light bulbs, and the option of reasonably bright lighting for fast downhill and flat stretches on bad roads. ---marty ps The TriLight would benefit by the addition of a small analog circuit (a mosfet and voltage level sensing circuit) that cut off the light when the battery voltage got dangerously low, and with a minor addition to such an analog circuit the light could be flashed or otherwise made to indicate cut off was coming soon. No microprocessor is needed to accomplish this, as Willie Hunt's LVR2 offers these features implimented simply by analog circuitry.