Re: How good a "sine" wave to drive a selsyn/synchro?


"Genome" <ilike_spam@xxxxxxxxxxx> wrote in message
news:xW8%e.4636$0w.1969@xxxxxxxxxxxxxxxxxxxxxxx
>
> "jtaylor" <jtaylor@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
> news:maW_e.17153$p5.6018@xxxxxxxxxxxxxxx!nnrp1.uunet.ca...
> > This sounds good but it's a bit over my head - how will I get the three
> > phases to vary at 120 degrees?
> >
> >
>
> Have a look at the bit about LFO generation using a ring counter at....
>
> http://www.geofex.com/Article_Folders/LFOs/psuedorandom.htm
>
> There is also a circuit in H&H, the art of electronics. I think you scale
> the resistors as some Sin(X)/X function but I can't remember.
>
> Use six of your pins on the pic to implement the walking ring counter and
> then add the summing resistors like this (arbitrary values chosen)
>
> Phase 1) Phase 2) Phase 3)
> 10K 15K 20K
> 15K 10K 20K
> 20K 10K 15K
> 20K 15K 10K
> 15K 20K 10K
> 10K 20K 15K
>
> So each set of resistors is shifted two bits compared to the previous one.
>
> DNA
>
>

Oh Crap...... that doesn't seem to work.

DNA


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