Phone line-powered flashlight (Free power from phone line)

 

Image Notes

1. Bridge rectifier
2. Here you solder the green wire from the phone wire
3. LM317L "Facing you"
4. 270 ohm Resistor
5. 6.8K ohm Resistor
6. Here you solder the red wire from the phone wire
7. 12 LEDs in series (negative with positive)

 

Soldering it together

So this is the schematic for the circuit.

My phone line delivers 48V DC and something around 20mA, and when the phone rings, it delivers 96V AC.
This works in a way that the phone line won't stay busy while the LEDs are connected and when you pick up the phone, the light goes off and allow you to use your phone normally.

-Solder all 12 LEDs in series (negative pin of a led to the positive of the next led)
-You will use the four IN4007 to make a Bridge Rectifier.
-Solder the negative pin of the last LED to the negative pole of the bridge and solder the positive pole of the bridge to the input pin of the LM317.
-To the output pin of the LM317 you will solder the 270 ohm resistor (R2), and to the adj. pin you will solder the 6.8K ohm resistor (R1).
-R1 and R2 will be soldered in parallel and then to the positive pin of the first LED.
-In the middle of the Bridge, where the ~ signs are, you will solder the RED and the GREEN wires that comes from the phone wire.
(The bridge is necessary to rectify the 96V AC when the phone rings)

Some phone wires have 2 more wires inside (yellow and black), we won't use them here.