OT: white LEDs

Curt @ Atari Museum wrote: Right. Instead of a single bulb, there are many smaller LEDs, and the biggest benefit is that they all don't fail at the same time. This makes them much safer. I don't know what the MTBF is on those things but I've seen a couple burned out in some of the lights around here. I used to talk to the technical people in charge of these types of projects in city/county/etc government. This isn't all that new, either. They've used RS422 and RS485 and run copper twisted pair between the lights, and then home run single mode fiber back to the centralized building. I got involved w/ them because they wanted to "network"-ify these old light controllers. The newer controllers are ethernet-based. I gave them a solution to transmit serial over tcp/ip, and then use small network switches that would use the legacy single mode. The advantage there was that they'd now have ethernet in these street-side boxes which made things like network-based cameras easy to connect. These switches had two single mode fiber ports (or multimode for shorter distances) and then around 6-8 copper 10/100 ports. What made them great for these types of projects is that they were industrial temperature rated. They were -50C to +100C rated, and designed for long term use at -40C to +75C. At the central location, they had big monitoring screens where they could see the status of every light, and have live video of the intersections. Pretty neat. Yup. I designed some of these types of networks too! Especially nice when they already have some of municipality wide wifi installed. Keith