Instrumentation amplifier to get discrete DC measurements of AC signal

[AlanTheWoo]

If i'm trying to measure a relatively slow (~1kHz) AC signal. Can I use an instrumentation amplifier to "read" discrete DC signals so they can be latched and sent to a computer for plotting?

The AC signals can vary and are not necessarily sinusoidal. I had one suggestion of using a low pass filter and then having a gain of 0.707 and then just re-creating a sinusoid at the computer. But this will only work on sinusoids and I want the display to accurately reflect the signal being measured

 

[Heydave]

The instrumentation amp should be the front end of an Analog to Digital converter. This device would then give you a value for the DC voltage at the instant it did the conversion. The microprocessor would read the value of the A/D at some interval thus creating points on a graph to recreate the value. This is a classic digital oscilloscope application.

 

[AlanTheWoo]

Yes, this is a digital oscilloscope application. Can you recommend any parts or things to help me make a better design? I was looking at single-chip instrumentation amps and also building my own from op-amps.

 

[Heydave]

Some A/D chips have differential inputs already.
Try these supplier web pages for parts using their selector guides:

http://www.analog.com/

http://www.linear-tech.com/prod/prod_home.html?product_family=atod

http://www.national.com/appinfo/adc/

http://focus.ti.com/analog/docs/analogprodhome.tsp?familyId=390&templateId=4