Picture of The Ultimate Household/Emergency Flashlight System
This flashlight and base work together to create the ultimate household flashlight system! The base makes a soothing night-light, keeps the flashlight charged, and will turn on a high-brightness LED if a power outage strikes. When the flashlight is removed from the base, it becomes a super-bright lantern to help you find your way, and will also work as a battery powered desk lamp.

Even though it is designed to help in a power outage, it also works as a perfect around-the-house flashlight. It is especially useful that you can set it down and bend the light to wherever you need it, and keeps your hands free. The base makes recharging easy and leaves the flashlight always ready to use, no need to mess with batteries.

It's also cheap and very easy to make!

How it works:

A wall-wart transformer is constantly plugged in and connected to the base. A PNP transistor has its base connected to the power in from the wall, and the voltage from that turns the transistor off. When it stops getting external power, the transistor is turned on and sends power through a connector to the flashlight. This turns on the flashlight's high power LED on a low power, letting out plenty of light to find your way but conserving the batteries. If the button on the flashlight is pressed, it goes to full power.

Now let's get started!
batman963 years ago
Could you post a schematic that uses normal batteries, and just uses the wall wart power to sense the presence of power, and to run the light if you want to switch it on when the power is on, I was thinking about using something like this with regular batteries for our wireless telephone base, when the power goes out it would switch to the batteries, like a mini UPS for computers, could you post a schematic?

dark sponge (author)  batman963 years ago
For that you can probably take out the voltage regulator, the resistors and diode connected to it, and the middle pin of the connector out and it should work. I'd like to see it if you make it, good luck!
Thanks, I will try it when I get a few other pressing projects done.

acoleman34 years ago
funny how some of these components look like they came from thecustomsabershop.com. especially the rebel star LED and the PCB. nice idea to have these plans available.
no actually....it looks like most of the SEOUL P4 LED blade kit now that i think about it. the switch looks like its from radio shack since teh kit only has a momentary switch.
dark sponge (author)  acoleman34 years ago
I got the LED (and pretty much everything else) from Mouser, I could look up the model number if you want. But you're right, the switch is leftover from the days when I would still shop at Radioshack :-)
hg3415 years ago
love how the chargeing base is a night light you need to work on a case
dark sponge (author)  hg3415 years ago
Thanks! Personally I don't think it needs a case, but I'm sure a lot of people would. If you make one, please send pictures!