The decision to go AC vs DC was made a long time ago. Of course, we would not go DC over the distribution network. However, we COULD have a low voltage supply and wire the light switches with a smaller guage wire, needing less robust switches. Perhaps a not trivial reduction in wiring costs, as copper has gone up dramatically.
We would still have the AC for appliances and such.
It would not be a big deal for new houses.
This would mean 2 types of bulbs- DC for new, AC for old. This could be a show stopper due to manufacturers probable unwillingness to have 2 types. But, if LED is the way of the future, why not use it as close to the "raw" state as possible? Cheaper for product, less manufacturing cost, less copper cost, less wiring installation cost. And, less high voltage AC in the walls
(BTW, I previously said DC for doorbell, incorrect. It is 12VAC, I think)
??? Wouldn't it be infinitely less disruptive (and I mean that pejoratively) to stick diodes in the CFL instead, if they prefer DC?
DC house current would mean that any appliance that doesn't require strictly 115 V would have to have a switching power supply. Not to mention, the electric utilities would have to co-locate gymongous rectifying circuits where they now have the final distribution transformers that go to 230 VAC. Which means, huge changes all over the distribution network.
Not a trivial change.
I have had somewhat the same results as DrQuine with CFL failures at home. In 2 years, I have replaces maybe 1/2 dozen bulbs out of the 30 or so that I have in service.
If one researches, it appears that the failures are due to the electronics associated with start-up.
In order to eliminate these issues, is there any effort to start wiring houses with DC for lighting? We already have DC for doorbells. This would be an easy extension, and would eliminate the cost of the start-up circuitry, and the associated failures.
We haven't anything remotely close to that. The CFL brands we buy are Sylvania or UtiliTech, which are sold at Best Buy. We've had much better luck than what you describe.
Basically, one failure that was premature, within maybe less than a year, one failure in a couple of years (which is also premature, in my book), and the rest keep soldiering on for many years.
As to going to laser lights, interesting concept. I wonder if the coherent nature of laser won't create some weird phenomena?
Our electric utility companies distributed many CFL bulbs for free, or at greatly reduced cost when they first came out. The fact that each CFL contains a small amount of mercury makes them much less desirable than LED's when you take into account the disposal cost.
Drones are, in essence, flying autonomous vehicles. Pros and cons surrounding drones today might well foreshadow the debate over the development of self-driving cars. In the context of a strongly regulated aviation industry, "self-flying" drones pose a fresh challenge. How safe is it to fly drones in different environments? Should drones be required for visual line of sight – as are piloted airplanes? Join EE Times' Junko Yoshida as she moderates a panel of drone experts.