You'll have a slow color changing candles group to enlight your living room during Christmas holidays.
Step 1: Parts and Materials
You need these parts and materials:
- slow flash color leds (browse ebay with these keywords), I used 3 of 5mm type
- moderately large votive candles, 3 as above, 6cm or higher and 6cm in diameter
- a base platter (wood, ceramic, metal ... I used a square piece of plywood, just too small, damn ... a plain porcelain dish would works great)
- a wall wart power supply (I used a 12V/100mA one, but every type from 5V upto 15V works)
- a female connector that match the power supply output connector (barrel, jack etc)
- a 5V/1A regulator IC(classic 7805 or so)
- a 100uF/16V electrolytic capacitor
- some insulated copper wires (short pieces from net cables work well)
- electrical tape or heat shrinking tube (2-3 mm type)
Step 2: Prepare the Candles
Ok, lets do it:
1) Depending from the led power and the candle wax type you have to reduce the candles height to obtain a reasonable and uniform luminosity.
Remove the top caps and extract the candles from the red cases, remove the wicks too.
(in the candles I purchase the wicks are separated from the candle wax body and easily removable, if you have wicks melted inside the wax you can try to pull them out or leave them there).
Insert a led on the wick's hole at the candle base and power it (with a 5V source, higher voltages will fry the led, try to arrange the power supply section on the fly for this test or use a 4,5V battery, longer lead is POSITIVE : DON'T REVERSE) to see how high the light would go so you'll realize how long the candles can be.
I found led can be pushed inside the candle to its entire lenght (leads included) and light diffused back to the candle bottom too.
You have to enlarge the hole or drill it from scratch depending from the wick type.
I cutted the candles from their original 13 cm to respectively 8,5 - 7,5 - 6,5 cm.
Three different height candles are putted together in a triangular way to obtain an armonic composition.
Candles stays together with the help of some metal (copper, steel) wire pieces plugged on their bodies at the middle (and the candle bodies hide them) and under the bottom, shaping in a "U" fashion and heating them with an iron.
Cut some copper insulated wire pieces to connect the led in parallel (positive with positive, negative with negative), extract the led from the candles to solder wires and insulated them with hot shrink tubing (3mm diameter). REMEMBER to INSERT TUBING BEFORE solder.
With another couple of wire connect leds to the power supply section
Step 3: Assemble the Power Supply
Not so complicated, but some infos are required.
Female connector, voltage regulator and the electrolytic capacitor are assembled together with the only support of the wood baseplate. I used a small self-threading screw on the regulator hole to secure all.
It may seems hazardous, but regulator is largely oversized (3 leds sink about 60mA and regulator handle 1A) , have internal short circuit and termal overload protections, so it can't ignite the wood baseplate. An heat sink may be used for more safety, also an U shaped aluminium foil piece can works, pay attention to avoid terminal shorting and metal pad itself is connected to the ground terminal.
Anyway keep it away from curtain or so and (standard disclaimer) "I decline any responsibility about your use of this device and damages and other effects that can derive from it. You are responsible of your own actions".
About the leads, facing the regulator they (hanging down) are from left to right: IN - GND - OUT .
Picture made with FidoCAD http://www.enetsystems.com/~lorenzo/fidocad.asp
PS: I found some standard cellphone charger work well to power this circuit without the voltage regulator, just substitute it with a 1N4007 diode.
Step 4: Put All Together
Finally secure candles to the baseplate. I used some long but subtle nails and screws from the baseplate bottom.
I think some adhesive works with other baseplate material you can't punch.
Step 5: Let It Show
At the end I found another plus: they can last forever !!