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I am using a sensor that outputs a 0-10 VAC (alternating current) and I need to convert this signal into a signal within 0-3.3VDC (direct current) to feed into an ADC.

What is the best way to go about doing this?

Is there an integrated circuit/breakout board that will take care of this conversion?

ADaniel
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    What is "0-3.3VDC" ?? If it is direct, it has to some specific value. – Eugene Sh. Jul 02 '15 at 15:47
  • Mention the frequency of AC signal. You would rather use voltage dividers and feed directly to ADC – User323693 Jul 02 '15 at 16:02
  • Simple resistive dividers in parallel with capacitor dividers may serve the job – User323693 Jul 02 '15 at 16:03
  • http://electronics.stackexchange.com/questions/53515/converting-0-to-24v-analog-signal-to-0-to-5v-for-adc-input similar – User323693 Jul 02 '15 at 16:05
  • Do you want the peak of the signal converting to dc or maybe the rms of the ac signal. Maybe something else but certainly a frequency range is needed. – Andy aka Jul 02 '15 at 17:19
  • Is it a humidity sensor? Did you look for it's datasheet? Often the datasheet includes typical connection schematics. – rdtsc Jul 02 '15 at 17:25
  • @EugeneSh., Not specifically, it can still be a DC waveform like a square waves, or just different levels of DC over a period of time. Sounds like he is just wanting to an AC voltage output converted to DC for an ADC... Though, with that being the case, I wonder why he just doesn't do a DC offset. Offset the AC signal to not be negative, then do a voltage divider to get 3.3VDC max. – Jarrod Christman Jul 02 '15 at 17:52
  • @JarrodChristman The question is rather vague. In the way it is stated, any any box with zero output will satisfy it. – Eugene Sh. Jul 02 '15 at 17:54
  • @EugeneSh. I need to convert an AC signal (whose peak can vary from 0V to 10V) into a DC signal (and this DC signal should have a max value of 3.3V upon conversion) so I can feed into an ADC.. does that clarify the question? – ADaniel Jul 03 '15 at 17:34
  • @JarrodChristman Yes I want the AC voltage output to be converted to DC for an ADC!.. so, doing a DC offset and the using a voltage divider sounds like a good idea...thanks! – ADaniel Jul 03 '15 at 17:35
  • @Umar The frequency of the AC signal is the same as the mains frequency ~ 60Hz – ADaniel Jul 03 '15 at 17:35
  • @Andyaka yes, I want the peak of the signal converting to DC – ADaniel Jul 03 '15 at 17:35

2 Answers2

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Why not an active peak detector? Something like this would do it, though you'll need to adjust the time constant on the output filter. This is assuming you're actually coming from the same ground, i.e. your AC wave is biased around 5V.

RYS
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If the input voltage is mains frequency and you wish a DC voltage reading, you can divide the input voltage down by about 5:1 and use a circuit such as this one from Burr-Brown:

enter image description here

Preferably use a CMOS type RRIO op-amp. R1 = R2 = (say) 100K and R3 = 49.9K.

Add an RC low pass filter afterward and buffer it to get smooth DC (and you could amplify it a bit with the buffer after filtering to get more of the range of the ADC). So only three op-amps and a few discrete parts.

Spehro Pefhany
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