Re: ac to dc
lats,
If you use the precision rectifier shown in figure 4 at
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h**p://sound.westhost.com/appnotes/an001.htm,
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then simply connect a capacitor in parallel with the feedback resistor R5. Select the value such that R5 X C is muchh longer thatn the period of the AC waveform. For example for 50 Hz, (period = .02 Seconds), a capacitor value of 100uF would work. This gives a time constant of 100X the period. You can reduce the capacitance value by scaling the resistor values up. By using 200K resistors, you could reduce thae capacitance to 10uF. The value depends on how much ripple that you can tolerate in the output.
Regards,
Kral.