Oz, On 27 June 2010 01:49, Oz-in-DFW <[email protected]> wrote:
> Soundcards have inputs and outputs. You can feed the output with a > series of samples that represent your control waveform. The PC becomes > the oscillator and you know it's frequency and relative phase track. Brilliant! > Chopping is used to cancel DC offsets in imperfect amplifiers, it adds > no gain. If there is a DC component and you filter with a cutoff > frequency below the chop rate, the offsets of the amplifier can be > effectively canceled. OK, I understand that. I'm not so sure this is the original problem I would have but thinking about it now I wonder if the chopped signal would end up being symmetrical with my original proposal as there is likely to be some small offsets thinking about it now. I could resolve this in software by sampling over a full cycle period of the chopper and then do averaging of the RMS readings. Thanks, Steve > -- > mailto:[email protected] > Oz > POB 93167 > Southlake, TX 76092 (Near DFW Airport) > > > > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > -- Steve Rooke - ZL3TUV & G8KVD The only reason for time is so that everything doesn't happen at once. - Einstein _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
