An electronic candle

If you're a special lighting for your party or simply close your meal? A candle illuminates the interior decor without risking to burn anything, anyone? Well, this article offers up a candle flame simulator-mail: you can use it to replace a traditional candle wax or stearin, which, unlike ours, burns and sinks. It is powered by a single button cell.

Figure 1: Diagram of the electronic candle.

The circuit is simplicity itself! A small microcontroller LED driver with a variable voltage.

This button cell still allows a range of more than fifteen days (five hours of operation per day), but if you want to use this electronic candle for religious purposes (votive), better predict a small supply 230 V and use it to feed several candles.
In any case, our electronic candles is very simple (see the wiring diagram in Figure 1) and it costs very little, either to realize it or use it. But look at this wiring diagram of Figure 1 more closely (oh, it will quickly).
It is a yellow LED high brightness (high yield) that conceals a piece of transparent plastic sheath: it emits a light variable, sometimes intense, sometimes less (like the flame of a candle wax or stearin).
For a good simulation, we preferred to avoid lengthy and logical modulators. We turned to a microcontroller that is suitably programmed, generates a voltage PWM LED illuminates randomly variable, the mike is a PIC10F200 in DIL 2 x 4 pins.
The resident program is not limited to simulate the flame of a candle, in fact, the PIC manages the entire operation of the circuit: it reads the button and, depending on the number of pressure by the user, it controls the ignition and Flora (pending), and the method of LED lighting.
But let's begin: when it is powered (by battery insertion button in its support), the microcontroller starts the main program, which includes a sleep mode (energy saving) and reading the logic state of line (GP3) which is connected to the SW1, the whole remains at rest and only consumes a few uA.
To light the "candle" (LED), please press once the button and it "wakes up" the microcontroller in the sense that the software detects switching, launch the program under normal operation.
This generates a PWM signal modulation (pulse width) on the line GP0.
The signal feeds the rectangular yellow LED of high brightness causing it to emit light continuously changing intensity, because this by varying the pulse width changes the value of the average voltage.
The change is pseudorandom in the sense that the program of ICP change arbitrary and anyway in a seemingly random sequence: the variable duty cycle square wave to simulate the flame of a candle.
Our tour can also operate in continuous light fixture: For the lighting of the LED light sets, simply press a second time the little push, the resident program suspends the wave PWM pin 5 is at logic 1.
A third press of this micropoussoir off the light (the candle) and goes back to sleep mode: micro then waits for a new press SW1 to wake up. The entire circuit operates under the voltage of 3 V button cell (preferably a CR2032, it is she who has the largest capacity).
The PWM wave is managed to settle for an average consumption of 3 mA (4 mA).
Is it necessary to clarify? This assembly is easier to build than its wiring diagram is "spartan"!
All necessary equipment is in one or another of our advertisers.
Once built the small board, it will do is choose a candle or lantern (or any other decorative object, use your imagination, bet it is.
already) to conceal the circuit
The printed circuit round lends itself well to any type of employment.

Figure 2: Photograph of a prototype of the plate of the candle-mail.

Iist EV167
R1 ...... 100 Ω
R2 ...... 100 kΩ
LD1 ..... High Brightness LED 5 mm yellow
IC1 ..... PIC10F200-EV167 already programmed in the factory
SW1 ..... micropoussoir

Others:
1 support for Battery CR2032 for it
1 battery CR2032
A clear plastic sleeve for LED
Unless otherwise specified, all resistors are 1 / 4 W 5%.