Re: if you are going to supreme

[Tim Vanderhoek <vanderh@ecf.utoronto.ca>]

On Tue, Feb 22, 2000 at 07:24:26PM -0500, Joyce Poon wrote:
>
> Circuits are driving me insane.  I tested them again in my room today and
> they work fine now.  ???

Different batteries?

Rewiring the relays in the detectors is still useful, though (just,
maybe, not strictly "necessary").


> I saw Sara's detector circuit today.  It has really good range.  Much
> better than mine.  Her circuit was simple, straight out of the book.  I
> think after the midterm evaluation, I will change the filter circuit to be
> powered at +9 -9 V so that everything has a common ground to everything
> in the sensor circuit. I am beginning to think that Malone was right in
> saying that we'll be much better off powering OpAmps from +9 to -9 rather

Actually, I was thinking about this more, and I don't think it's even
necessary to have a true -9V supply in order to avoid changing logic
levels: the peak rectifier would have functioned just fine at +12V.
It's output (which would be digital) could then be logic-level shifted
without any loss of signal.

I'm not discouraging you from trying to switch to a +9 to -9
configuration, though.

There may be other subtle benefits to having true -9V supply.

Hmmm......


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