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digital lightbulb

a bulb that tells you when it will blow
  [vote for,

its dark and you switch on the light. ping! it blows. don't you just hate that.

bulbs are designed to last a predetermied time, so why not put a small (inexpensive) microchip timer on each lightbulb that terminates it. the microchip can also tell a suitable quipped lamp how many burn hours are left.

then you can replace the bulbs before they go.

barkinghugh, Sep 05 2003

Screw base LED bulbs http://www.sunbrite...t_listing.asp?id=42
[AO, Oct 04 2004]


       "I used my microchip timer, but they still went soggy" quipped the (standup) lamp.
squeak, Sep 05 2003

       The timer should be attached to the light switch, not the bulb.
phundug, Sep 05 2003


       It's time.
Amos Kito, Sep 05 2003

       Bulbs do not a predetermined time, but an average lifetime. Simply counting down the 1000 hours (or whatever) won't do you much good if the bulb blows at 923 or 1224 hours.   

       However, I suspect that the current through the filament will change as it approaches the end of its lifetime, so monitoring that over time and applying a diagnostic system to the measurements would allow you to predict the bulb's failure.
DrCurry, Sep 05 2003

       Since the failure always seems to occur when the bulb is turned on, you could program your lamp to slowly ramp up the applied voltage while monitoring the current.   

       If it detects that the resistance or the filament has increased over a certain limit, then it knows the filament is about to burn out and it backs off the voltage, giving you enough light to see by, but not so much current as to burn out the filament. It also starts beeping to indicate that you should change the bulb.
AO, Sep 05 2003

       I think the bulb should have a small light built into the base of it that comes on to let you know the bulb's burnt out.
waugsqueke, Sep 05 2003

       I got wise and looked all over and finally found a supplier of traffic signal bulbs. They are guaranteed 8000 hours with constant turning on and off in all kinds of nasty weather. That was a couple of years ago. I haven't changed any lightbulbs since then. Now I see they are changing all the traffic signals to LEDs around here so the bulbs are even harder to find. But that's OK, LEDs come in white and are rated 100,000 hours and are suddenly getting cheap especially from china. Get them before they put blow chips in them.
mr2560, Sep 05 2003

       //The timer should be attached to the light switch, not the bulb.//   

       That's kind of baked. I had to do a lab experiment where we measured voltage and current for a bulb in operation and cold. You could see when a bulb was old because the ratio hot/cold resistance went through the roof. Such a devices could be built into a switch these days to predict failure. I don't know if anyone offers it.
kbecker, Sep 05 2003

       ...and this is the bulb that goes Ping.

The number of psychiatrists needed to change a light bulb is dependant solely upon the light bulbs desire to want to change.

       Making a light bulb last longer isn't difficult. Running a light bulb at 90% of its rated voltage will make it use a little less power while being significantly less bright but lasting many times as long. "Long-life" bulbs are often fairly ordinary bulbs that are rated for 130-135 volts. In most cases, the cost of extra electricity required over the life of the bulb exceeds the savings in light-bulb purchases. On the other hand, for light-bulbs which are difficult to replace, the reduced frequency of replacement may be worth it.   

       I do like the idea of a switch which responds to a nearly-failed bulb by dimming it.
supercat, Sep 06 2003

       I'm just waiting around for screw-base LED bulbs with incandescent spread and colour temperature.
Cedar Park, Sep 06 2003

       [Cedar] see link
AO, Sep 08 2003

       Saw those, but all are special-purpose lower-output types. None are designed to replace the standard bulb. The globe style bulb produces only 6 lumens. An 60-watt bulb makes about 855 lumens.
Cedar Park, Sep 08 2003

       Obviously, Cedar, you have yet to install any 140-socket light fixtures in your house.   

       (By the way, does anyone know how to translate mcd into lumens?)
AO, Sep 09 2003

       There is no direct conversion, since a different measuring system is used for each. LED's are measured in millicandela, or mcd. The output measured is in their projected beam, whereas a light bulb produces a spherical projection, with a constant brightness of rated lumens in all directions (except towards the base, of course).
Cedar Park, Sep 10 2003

       Check out this NEW type of EASYDIM Lightbulb .   


       Lasts upto 30 Years !
designs, Mar 17 2004

       EasyDim doesn't seem terribly new. I have a microprocessor-controlled light bulb (incandescent) that slowly dims to nothingness when left on for over IIRC 30 minutes; other variants were available with built-in dimming, flashing, etc. I think on the other one the bulb would come on full-bright but flicking the switch rapidly would change to dim. Regardless, those microprocessor-controlled bulbs were available more than five years ago.
supercat, Mar 18 2004


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