Arduino Sine Wave Dimmer

The pwm signal of an arduino is faster than the 50hz frequency so you will basically see the pwm signal modulated on the 50hz rectified sine wave making the effective voltage lower.

Arduino sine wave dimmer.

Demodulated waveform of variable frequency sine wave using arduino on cro. You just have to program the arduino board with the spwm code as explained in the. 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. 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.

In our post for this we use pins 5 and 6 that means timer 0. The figure 2 demonstrates the schematic diagram of the whole circuit. The figure 1 shows the mains sinusoidal wave with the frequency of 50hz sometimes 60hz. To generate a sine wave we will use two pins one for positive half cycle and one for negative half cycle.

First zero to control the passing of phase null of ac which is used to initiate the interrupt signal. The above chopped signal may not look like sine wave. A zero cross detector circuit is required for ac dimming purposes. Second dim psm to control dim current.

It is not for any inductive load as it is dc biased. Ac dimmer circuit made by using triac and optocoupler. A real sine wave inverter s chopped wave form increase and decrease exponentially across x axis. 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. The square wave can be observed using a cro which is connected to the pin number 8 and the sine wave can be. 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. Program developed by r girish.

To build a dimmer the zero crossing points the points where the wave changes its polarity are important. For a smooth signal we choose phase correct pwm at a frequency 31372 hz see previous post. But begin a simple design the chopping frequency stay constant and good enough to run most of electronic gadgets. This circuit is only for incandescant bulbs.