You can always find the lastest version of this instructable on my site at http://8el.eu/2010/08/himalaya-salt-lamp/ .
Step 1: Required Parts
- Himalaya salt horse lick stone with hole going through it
- old cellphone charger (5V)
- LM317 voltage regulator
- 100mA LED
- 15 Ohm 1/4W resistor
The lick stone can be bought for cheap in horse shops.
As for the cellphone charger: everybody has one lying around, if not, you know someone who will!
The electronics parts can be bought in any large electronic site online,
or in my shop at http://8el.eu/shop/ .
Step 2: Schematic
Step 3: Preparing the Charger
Use a scissor to cut of the end of the wire. Also use a scissor for stripping the wires as they are really thin!
Step 4: Soldering
Bend the resistor and solder it on the Adjust and Out pins of the LM317 and solder the LED with its long lead on the Adjust pin.
Bend the leads to get a nice stable shape.
Check the pictures to see how it looks from different angles.
Step 5: Connecting the Charger
Don’t be surprised if the voltage meter reports more then 5V! Our Nokia charger reported 7V. This is because the charger is not a “stiff” voltage source. It behaves as if a small resistance is in series with it’s output. When an actual load like our LED is attached the voltage will drop to the expected level.
Solder on the charger wires with VCC on the VCC pin of the LM317 and GND on the short lead of the LED.
Test it by inserting the charger in a power socket.