can power be genrated by just switching a switch on and off?
140958
To answer your question first: Yes, it will generate a back EMF in the circuit each time the power to the electromagnet is turned off, but this energy is never equal to the energy which was originally applied when you turned the switch on.  Nothing in life is free :)  \n\nWhat you're describing is actually called a transformer. A transformer works by applying an alternating current (equivalent to turning your hypothetical switch on and off very quickly, many times per second) to one coil, which induces current in another coil (or several, depending on the design).  \n\nWhile a transformer can be relatively efficient, it can never be 100%, and certainly not MORE than 100%, as you describe.
775866
I don't think you can do that. you need the number of amps and the power factor for that device.
167412
My suggestion would be to use a d.c. motor .  Incorporate the following : A D.C. motor, 2 momentary contact up/down switch, a reversing relay that would switch positive and negative when switching from up to down . Associated micro switches and ice cube relays to sense position and stop motor when destination is reached. Some form of safety clutch,light curtain etc. And a rectifier to convert house hold alternating current to D.C. . An alternative would be a reversing A.C. motor and associated similar controls less rectifier. Similar installation difficulty , my decision a/c vs d/c would be based on price and availability.
820704
Good Idea..but probably expensive to hook up the equipment to some sort of generator....gotta keep the place looking clean.\n\ninresponse to answerman....(below)\nIt could be possible to keep a battery bank charged and use an inverter to run a small a/c.\nSort of like a solar setup or windmill.
164324
Yes. Easy. Go to  the energy saver in system preferences and regulate the turn off time there.
629622
Never. This allows your computer to charge its battery in case you want to unplug it for more mobility. It doesn't matter if your computer is one or off because it will still recharge the same way as usual.
823421
light duty is the problem - would be very easy to make one using any push on connector in the circuit ( you need a spring loaded connector with the pin being non conductive - a 'blade' shaped pin would be the easiest to rig )\n\nanother possibility is to use a switch of any type ( a - b ) that shunts the circuit to a open   circuit  ( this can be activated by a pull - and switched back manually )
616514
Generating static electricity.
427780
Modern day systems are designed to use very little power actually..loaded for bear or not. printers use a heck of a lot more and a server is a computer generally speaking.the power use would epend on what you made it accomplish ie: is it hosting a zillion things or just one?\nI think in either case a 100 watt bulb or two would probably burn more energy if left on constantly than a comp does, especially if you set it to go to sleep or power down when you're not using it
160968
use as a mirror, when it's switched off
1170073
plug it in, flip it on
899465
Yes, you can. The laptop will be totally fine as all the information is stored permanently on the hard drive, which doesn't require power going to it for the information to stay safely on there. If you unplug the router then you *might* need to set your net connection up on it again afterwards, but as long as you're comfortable doing that then it's no real problem.\n\nOh, and I disagree entirely with Derek D's advice. People run their laptops until the battery's completely flat all the time, it's a totally commonplace event and requires nothing to sort except plugging it in again and letting it charge up for a while.
73266
try http://www.switchboard.com
964532
Sure, you can make a switch that is activated by almost anything including motion, moisture, sound, temperature, etc....
337406
Try going into the Control Panel, and selecting Power Management.  There might be an option in there to change what the computer does when the "lid" is closed.
502126
is it not that obviouse? WIRE LESS.
255379
I run my web server on one. http://bibleprojector.servehttp.com\nIt only takes 20W to power.