I got a simple problem. My objective is to measure voltage and power factor of a 16V AC through a differential ADC (ADS1115) that measures voltage difference between 2 channels. I only managed to measure current accurately through a CT.
In the positive cycle of the the circuit shown, the voltage across the 1k resistor is 1.45Vp which is measurable. In the negative cycle, the voltage across the resistor will be -14.54V which will burn the ADC.
Hence, how do I modify this circuit to achieve a safe voltage measurement? I will need to detect the waveform at point 0V in order to compare it to the current then measure power factor. I thought of connecting A2 to the ground of the DC supply instead of the nuetral, but I was not sure if that's the right approach.
Sorry i'm a beginner. Any input/ advice will be highly appreciated.