Arduino Sine Wave Dimmer

Program developed by r girish.

Arduino sine wave dimmer.

Opening the triac after a number of microseconds delay starting from the zero crossing therefore gives a predictable level of dimming. This one channel ac dimmer made using the arduino uno board using a specified coding. A real sine wave inverter s chopped wave form increase and decrease exponentially across x axis. This is a circuit that tells the arduino or another micro controller when the sinus wave goes through zero and therefore gives a defined point on that sinus wave.

The square wave can be observed using a cro which is connected to the pin number 8 and the sine wave can be. Demodulated waveform of variable frequency sine wave using arduino on cro. For a smooth signal we choose phase correct pwm at a frequency 31372 hz see previous post. Second dim psm to control dim current.

This provides a stable signal at every zero level of the waveform and sends a signal to arduino to know about each zero level of a sine waveform. The figure 1 shows the mains sinusoidal wave with the frequency of 50hz sometimes 60hz. It is not for any inductive load as it is dc biased. To grab these points we have to use a zero crossing detector.

A zero cross detector circuit is required for ac dimming purposes. The figure 2 demonstrates the schematic diagram of the whole circuit. In the last article we learned how to generate sine wave pulse width modulation or spwm though arduino we are going to use the same arduino board to make the proposed simple pure sine wave inverter circuit the design is actually extremely straightforward as shown in the following figure. The above chopped signal may not look like sine wave.

To generate a sine wave we will use two pins one for positive half cycle and one for negative half cycle. To build a dimmer the zero crossing points the points where the wave changes its polarity are important. This circuit is only for incandescant bulbs. But begin a simple design the chopping frequency stay constant and good enough to run most of electronic gadgets.

When the coding is finished one can verify and upload the code to the arduino board as explained in the project how to get started with the arduino. First zero to control the passing of phase null of ac which is used to initiate the interrupt signal. Dimmer is connected to arduino controllers via two digital pins. You just have to program the arduino board with the spwm code as explained in the.