FYI, one of the advances touted for Windows Vista is a new driver model which pushes most of the driver code outside kernel space, making it more difficult for a badly-written driver to crash the OS. The upside, of course, is that it should make crashes less likely. The downside is that many drivers need to be rewritten, and some never will be - there's little incentive for manufacturers to support stuff that no longer contributes to their cashflow (the two-year-old Toshiba tablet PC I'm typing this on is a particularly depressing example :)
Been busy on other projects. Also had a classic worst-case disaster a while back - simultaneous hard-drive failures in my laptop and primary desktop computers, and since they were backing each other up... Lost a bunch of email; managed to recover most of the other critical stuff. Needless to say, my backup strategy is a little different now :)
Anyway, about Insteon:
My house was built in the early fifties. And the sixties. And the seventies. And the eighties. The house is now about 4000 square feet, about 90 feet end-to-end, and has an "interesting" mix of wiring styles. My HA computer is at one end of the house, a long distance from most of the stuff it controls. X-10 was always marginal, even with an array of phase couplers, boosters, filters, all the usual stuff. I've been completely Insteon for about a year now, and power-line control has been absolutely reliable. I was using my own HomeSeer plug-in until the disk problems; when I rebuilt the system I installed the "official" HomeSeer Insteon plugin.
My biggest reservation about Insteon right now is the physical reliability of the devices. Out of thirty or so SwitchLincs, I've got two SwitchLinc Relays with bad rocker contacts - one won't turn on; the other won't turn off. Both work fine under power line control. Even more alarming is that I've had three or four LampLincs die when bulbs they were controlling burned out.
All of my Insteon stuff is early production; I'm about to get all the failed devices replaced under warranty - I'll see if anything's improved, quality-wise.
I recently lost an old laptop. It never recovered from a defrag. Fortunately, I could boot DOS and see the HDD so was able to salvage the files.
I have a network HDD that I try to use for backing up the things I really don't want to lose but the actual backing up is hit or miss. But the most critical stuff is distributed among 3 machines.
Could it be the Lamplincs went bad and took the bulbs out? I think that's more likely. Someone else reported 2 similar incidents on the Insteon forum and I suggested he make sure the latest failed module gets to SH engineering and they've taken steps to do that.
Your experience is sorta what I expected when I first looked at Insteon and reviewed it here. The basic technology looks good - Smarthome still looks like Smarthome. :(
Hard to imagine how a defective LampLinc could damage an ordinary 100W incandescent bulb. On the other hand, it's easy to see how a current surge as the bulb dies (typically accompanied by a blue flash) could damage a triac.
Why would there be a surge when the (resistive) circuit opens? The inrush current when a cold incandescent is turned on is significantly higher than after the filament heats up. If the filament is thin in a spot, the normal inrush current causes it to break.
On Fri, 15 Dec 2006 22:27:03 GMT, snipped-for-privacy@whocares.com (Dave Houston) wrote in message :
Dave,
When a tungsten filament fails, a "tungsten arc" can occur through vaporized tungsten connecting the ends of the foreshortened filament. There is a positive feedback in this effect, so as more tungsten is consumed to support the arc, the current path through the remaining filament becomes shorter, and the current increases causes more vaporization. This can result in the bright flash that is sometimes seen when a filaments fails.
This is a well-known phenomenon. Some lamps have fuses built into the base to provide some measure of protection. One of the functions of the RC snubber circuit across a TRIAC is to protect the TRIAC gates from inductive spike during filament failure that can damage the TRIAC. This is also a problem with IGBT and MOSFETs used in reverse phase dimmers.
If the branch circuit has appreciable inductance, then when the current first increases and then abruptly goes to zero when the internal fuse blows, a small voltage spike could be generated. This could damage other equipment on the same branch circuit, but I have never seen or heard of such damage.
Yes, a failing incandescent lamp can cause a current surge if the filament arcs as it falls apart. That's been well known for years. Incandescent dimmer manufacturers usually handle the situation by inserting a small impedance in the output circuit to protect the solid state parts which, of course, act faster than the thermal fuse in the lamp.
General service inandescent lamps are gas filled and fused. That's because when gas-filled lamps were developed in 1913, manufacturers learned quickly that an arcing filament was bad for business as it caused lamps to shatter, bases to melt and sparks to fly around.
The fuse is in one of the leads in the "stem" or glass support structure for the filament. If you take a lamp apart, you will see that there are different kinds of wire going from the base or cap up to the filament. The filament, of course, is tungsten. The support wires are Molybdenum, but they are welded to a wire of nickel-iron alloy covered with copper called Dumet which has the same coefficient of expansion as the glass which surrounds them. In one of the leads toward the cap, there is a fuse wire as well. It may be inside a tube surrounded with glass beads called ballotini which helps to quench any arc as the fuse opens. All lamps sold in the European Union must have a fuse which complies with IEC 432-1, a lamp safety standard. I don't know if there is a similar standard for the fuses used in North American lamps.
What are the physics of the mechanism(s) that would cause a INSTEON Lamplinc dimmer (TRIAC output device typical of residential US dimmers) to 'take out' lamps?
And why, as Dave thinks, is this "more likely" than the well-known phenomenon of a current surge owing to tungsten arc when the filament fails causing the TRIAC in the dimmer to fail?
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