hey all,
i am in a situation where i have to measure the AC main voltage using a PIC. i am planning to attenuate and shift the AC voltage to a 0 to 5V, 50Hz signal. to couple this signal to the microcontroller i was planning to use a linear optocoupler. but i cannot do that anymore as they are pricy, hard to find here and concerns about the linearity range.
so i am thinking about converting the 0 to 5V, 50Hz signal to a PWM signal where the pulse width changes according to the sin wave amplitude and then couple it using a normal optocoupler, LPF and then give it to the A-D of the PIC.
OR
use a VCO --> optocoupler --> frequency to voltage converter --> A-D of PIC.
are these methods feasible and how accurate will they be ?????
thanks in advance !!!!!!!!
i am in a situation where i have to measure the AC main voltage using a PIC. i am planning to attenuate and shift the AC voltage to a 0 to 5V, 50Hz signal. to couple this signal to the microcontroller i was planning to use a linear optocoupler. but i cannot do that anymore as they are pricy, hard to find here and concerns about the linearity range.
so i am thinking about converting the 0 to 5V, 50Hz signal to a PWM signal where the pulse width changes according to the sin wave amplitude and then couple it using a normal optocoupler, LPF and then give it to the A-D of the PIC.
OR
use a VCO --> optocoupler --> frequency to voltage converter --> A-D of PIC.
are these methods feasible and how accurate will they be ?????
thanks in advance !!!!!!!!