hi
i am using ad 736 as precision rectifier to measure ac mains current using shunt resistance tecnique.
i wnt to know that how can i get ripple free o/p that is pure dc voltage which can fed to microcontrolar.
(please specify the value of R and C for low pass filter)
Strictly spoken, you can't get a ripple free output of a low pass filter. You do a trade-off between ripple and response time,
as discussed in the AD736 data sheet. To achieve a true ripple free output with finite response time, averaging over full mains
frequency cycles (e.g. by the processor) would be the most effective method.
Page 14 of the datasheet gives a table of suggested averaging and filter capacitor values for different signal types. 150uF for the averaging and 10uF for the filter would seem appropriate for your application, I would have thought.
I'm confused by the question! The AD736 takes an AC signal and turns it into a DC RMS one. The connections to do this are described in the datasheet, e.g. figure 18.
Thanks
bt fig 18 is to complicatd.
Can i use fig 11 without voltage divider ckt.
In my project when i connect shunt to ac mains with load of 100 watt bulb then i got 4mv reading across shunt using multimeter.
I want to measure this 4mv using microcontroler so i need to convert this 4mv into dc then fed to adc and then to microcontroler..
Plz help me to design this ckt