This article shows how a nice Himalaya salt crystal lamp can be made from a few cheap parts and an old cellphone charger.
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
This are the 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
This is the simple schematic. First try to make it on a breadboard.
Step 3: Preparing the Charger
Looking at the specifications of the charger more in detail shows it can deliver maximum 350 mA at 5V DC. It should be safe to use it at 100 mA.
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
Now it's time for soldering the final shape.
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
First you need to know which of the wires on the charger is the VCC (+) and which the GND (-). This can be tested by measuring the Voltage with a multimeter. If the voltage is negative, the Red lead on the multimeter is touching the GND wire, if it is positive it is touching the VCC wire. Alternatively if you have no multimeter, just test by touching the wires on the model like described below, and the correct way will light the LED, the wrong way won’t. In our case the black wire turned out the be GND and the white wire VCC.
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.
Step 6: Adding the Salt Crystal
Place the Himalaya salt crystal with the hole over the LED, and it should provide a nicely illuminated effect, as shown here with a warm white LED and a red LED.
Be sure to check out my articles page for more fun.