triac firing and pulse generation

[stepsan78]

Hello,

I would like to create activate a TRIAC and control its firing angle (e.g. dimmer). 

I work with a cDAQ 9178. I can generate a 50Hz train pulse with NI9472. Further I can monitor the zero crossing voltage with a circuit that I made, so that I read 0 or 5V depending on the voltage wave. My issue is that I don’t know how to synchronize the pulse generation with the zero crossing and how to change its firing angle.

I attach the VI. I can only set an initial delay but I can not refer it to something or change it later. I hope that somebody can help me.

[lagunasol]

Hello, I am working on a similar project but using FPGA Instead, my biggest problem is lack of knowledge, since I need to use an inverse cosine in my fourmula in an RT Target and then send those values to the FPGA vi, and because of that I am having desync and lost of data. 

Anyway, I am not sure if this would help but this is what I am using to synch with the zero crossing and to control the phase angle I want to shoot the pulse. 

The attached vi first checks if there is a change of sign for the zero crossing (or in your case you can use an event handler or consider each pulse as a true value) and then it starts the case, in which there are two tick counters for ms and us (whatever you preffer to use, I use us for more exactitud in the pulse), it is the same principle to know how many time it takes for a code to be executed, but that result I use it as a counter and then compare it with my control variable (the phase angle in time, there is a convertion inside to change from rads to time in ms or us) and when the counter is greater than the control, it shoots a pulse (you can change it to digital or analog pulse)

My project is a three phase full control full wave rectifier, but I use three Triacs instead to cut each phase of the three phase sigal, I am still having issues with the time, but the attached vi can control the pulses, once I incorporated to my whole code it starts getting some delays. We are controlling in different ways, but I hope we could work together since our projects seems to be alike. 

Thnanks in advance!