Setting up a solar powered LED night light?
444057
I agree that a relay is useless.  Everything needs to be very low power (i.e. use MOSFETs).  Capacitors might work if you use the new "ultracapacitors", or DLC's, which have huge capacitance and tiny leakage.\n   Since it's solar powered, you'll have a photocell.  You can use this also as the light detector.  When the photocell is producing current, charge your battery or ultracapacitor.  When photocell voltage drops below some threshold, turn on the LED.\n   A simple way to go would be to use two or three photocells in series, and run through a diode to your battery/ultracapacitor.  THen, run the battery/capacitor positive terminal to the source of a p-channel MOSFET, and run the drain to your LED (with a series resistor to control brightness).  Control the gate of the MOSFET with the positive terminal of the photocells.\n   When the photocell voltage drops a few volts below the battery, the MOSFET will turn on, energizing the LED.  When the photocell is .7V more than the battery voltage, the battery will charge.
587901
get one of those electrical outlet timers that are used for turing lights on etc.. and lock it in the closet with your router, and or pc
174120
Get a ac to dc converter and just add a plug to the light bar.
18707
The answer depends on how big or how much each solar panel produces.  But you definetly need at least 1,200 Watts. You can either try to produce the energy Chemically or Mechanically.  Chemically you need Photo Electric Panels Large enough to produce 1,200 watts.  Mechanically you would use mirrors to focus the suns rays onto a boiler to create steam and then turn a turbine generator.
173110
attach a light bulb to a battery and have current pass through the different cups, the more current the brighter the light.
113216
One assumes that you are speaking about a house that is powered by solar source energy, and not a proper solar system, with a star and attendant gases and planets.  However, this questions is under physics for some reason.\n\nIf that is so, I wouldn't advise a DIY project unless you are an electrician.  There are several ways to convert a house to solar-source power.  First of all, you want to do an assessment of your geographic location and the number of average solar access hours per year.  If you are in Minnesota, for example, it might be very difficult to get enough exposure.  You also will want to check the exposure to sunlight that you housing lot has and any obstacles caused by vegetation or buildings.  There are just some things you can't change, like your neighbors 50-foot tall eucalyptus trees that are between your lot and the path of the sun.\n\nSome people use passive solar design to achieve lower energy bills, rather than go to the expense and trouble of buying and installing a solar-powered system.  This can mean insulating your house more efficiently, improving R factors through the intelligent use of batting, windows, materials, etc.  You can also try installing zone HVAC systems.  Additionally, using any local winds or planting vegetation to help cool your house helps.\n\nPassive solar can lower your dependence on electrical or gas source powered, but you will still need electricity.  IF you get enough sun, or have enough acreage and money, you can install photovoltaic solar panels (think sky lab) to capture energy which you would store in fixed batteries (a lot of them, even today).  For example, a 20W flexible solar panel costs about 300 dollars (you can charge a 12V battery or use some minor DC appliances (as long as you have sunlight).  So to run a stereo, you might need about 20 of these, and while the fleixble kind are more expensive (but portable), you are looking at 6000 dollars.  Of course, accumulated in batteries, this might not be so bad.  There are also low-light panels available, too.\n\nThere are all kinds of different ways to do what you have in mind.  The type of method will depend on the desired outcome.  Heating water, for example, will be different.\n\nGood luck, while there are DIY kits for mobile homes (which are plug and play) I don't advise messing with your wiring system unless you know what you are doing.
1020503
1. A battery lighting up a filament bulb.\n\n2. Use LM317 IC to build a constant current source.\n(http://www.uoguelph.ca/~antoon/gadgets/sccs.htm)\n\n3. Battery Charger
125051
look for a buttons with different color codes on them or above them.  Look for a mode or shift button. in the same color as the. You may have to hold down the mode or shift button at the same time as pressing a button with AC or ON above it.  If that does not work try pressing the mode first then the AC button.  You get the idea.\n\nIf it is a solar calc, do try to cover the solar panel to see if that powers the calculator off.  If that works, then just keep it covered.\n\nIf non of the above works.  Check online at the manufacturers website for  the make and model amnual or a phone number for customer service.  Do not give up until you get your calculator turned off.\n\nLast resort\nIf it plugs in the wall yank the plug.\nIf it has batterries, pull them out.
134155
Put a TV, and computer monitor on the ceiling.\njust kidding, roll over to the nearest light source and turn it off and on at a constant rate.  hopefully someone will see it through a window.
34735
Use a night light.  Turn it on everynight before you go to bed.  I'm sure after awhile you'll forget about turning it on and won't even realize it.  Also, lots of times if you open up your curtains or blinds a little bit light from outside comes in.
587734
Yes....do it on alternative energy sources
1101885
This is a perfect question for the section called 'corporations'.\n\nThe answer is 'NO'. Even though you leave the light switch on, the burned out bulb breaks the circuit and uses no electricity.
313345
solar,  sun light, hydrogen
664846
extra lighting, make it super bright
530744
An alternative energy source
454478
They have done studies that unless the lights are in the South West there is not enough sunlight throughout the year to make an efficient product. I think it was England who first attempted to use the solar powered lights. But they have far more foggy/cloudy days. So I am sorry solar powered traffic lights are not a good idea.
177665
Here you go...\n\nhttp://www.electronicsforu.com/EFYLinux/circuit/dec2003/CI-01-night-lamp.pdf