My Triac circuit that is controlling a motor load that has ringing when it turns on and off. Even when feeding a resistive load the ringing is present.
I have a 0.33uF Snubbing circuit on the output of the triac. The input voltage is 230VAC and either 50Hz or 60Hz. The images below was on a 60Hz source. The circuit will be used on both 50Hz and 60Hz.
I have read that the noise could be cause be the phase angle when I turn the triac on as well as not having a snubbing filter in the gate portion of the circuit.
I am rather confused as to what is actually causing this "spike" or ringing. I have tried controlling the load a couple different ways. The first was maintain the turn on angle and then varying the pulse width and varying the phase angle based on the zero crossing.
Both work but both have the ringing noise in the waveform.
What can I do to correct this, change the firmware, add a filter on the input? Change the value on the Output cap? Change the value of the trigger resistor?
I have played with all of the above thoughts but nothing seems to make a difference.
This is the ringing shown as the triac is switching.
Here is a different view showing the input and output signal.
This is the circuit controlled by a PICF689