My basement hallway can get very dark at night, making it dangerous to walk when I don't want to tur on on the lights. I could splurge and install a wall socket, but that would cost too much for this minor addition. I could install a nightlightwith batteries, but it would eventually run down and need replacing.

my home is probably not the only one designed with this flaw, so I imagined a self-charging nightlightthat plugs into a standard bulb socket. it would have one end that plugs into the socket, and a second that accepts a light bulb. in between, there is a collar bearing LED's around the edge. there is also a NiMH or LiIon battery and charging circuitry. when someone turns the power on for a few minutes, the battery charges and the LED's turn off. when the power is off, the LED's run from the battery.

This is kind of like the solar LED garden/walkway lamps people install outdoors, except this one charges from house current.
-- squirrelecule, Aug 27 2010

Backup Bulb Backup_20Bulb
[xaviergisz, Aug 27 2010]

Patent application for a "Light Bulb System" http://www.faqs.org...nts/app/20080304272
Sounds pretty close. Not sure what the patent's status is. [jutta, Aug 28 2010]

I like it a lot.

You could maybe put a capacitor in there that charges up in the few seconds that the light is on. A battery takes some time to charge, a capacitor is pretty quick.

Is there anywhere a rig that charges up a capacitor, then trickles that charge into a battery? Or would that be a waste of time? Sticking with the capacitor might be better.

[+]
-- baconbrain, Aug 27 2010


Interesting. What's the minimum time the AC power would be on, powering the conventional lightbulb?

What's the maximum time you'd want the LED lights to be on after you removed the AC power?
-- csea, Aug 27 2010


//My basement hallway can get very dark at night, making it dangerous to walk when I don't want to turn on the lights//

There's your problem. Turn on your lights.

Perhaps the problem is you only have a light switch at one end of the hallway and not the other?
-- xaviergisz, Aug 27 2010


(+) My brother bounced this idea off of me a few months ago.
Made me swear that I wouldn't post it here.

.

He's not going to take this well.
-- 2 fries shy of a happy meal, Aug 27 2010


Neat [+]

But you would do better with cybernetically integrated night vision and a laser pointer strapped to your temple ...
-- 8th of 7, Aug 27 2010


Had the same problem in an old converted house. There were no windows in the hall, so it could get very dark and toes would get stubbed while stumbling about. Turning on the bright lights wakes me up too much, so something nice and dim was called for.

In the end I opted for a battery powered LED PIR lamp. A couple of the scattered about gave enough light and lasted for over a year. The key being, that they are turned off most of the time, and so the average power consumption is very low. Was tempted to put a solar cell on them to keep the batteries topped (when the bright lights are on) up but didn't get round to it.

With your idea, super capacitors would work well as one holding 1000J is about 2" long and 1" diameter. This could easily run a 0.25W set of LEDs for an hour. If coupled with a PIR sensor, this hour could be spread over several weeks. Charging the capacitor could easily be done in 10 seconds.

0.25W might seem low, but if your eyes are dark adjusted, it's ample for walking about. It's about the power of a head tourch.
-- saedi, Aug 27 2010


I've seen quite a few variations on dimming wall switches (which of course aren't going to work right for CFL and LED bulbs but thar ya go)... the one I think would work best has a heavy detente about 1/4 the way up: this is the OFF position. Full up is ON and full down is DIM (adjustable by a tiny linear pot off to the side).
-- FlyingToaster, Aug 27 2010


There are dimmable CFLs, although they don't have a full range. There are also dimmable LED bulbs which do have a full range.
-- MechE, Aug 27 2010


If you were a pop star there would be no problem as a normal light turned on full would look like a night light due to wearing sunglasses indoors...

Perhaps it's time to start singing badly!
-- saedi, Aug 28 2010


I read this as "self charging nightclub" for a moment and had visions of an electricity themed nightclub with charged floors, machines that make you dance with electricity, arcs through the air, and other such goodies.
-- Voice, Aug 28 2010



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