[time-nuts] ? phase comparison or other device
Dr Bruce Griffiths
bruce.griffiths at xtra.co.nz
Sat Jun 30 19:50:40 EDT 2007
Pete
Try changing your input stage to the configuration depicted in the
attachment.
The input amplifier can then be something like an OP27 without affecting
performance.
The noise spectrum at the first opamp output will actually be reduced to
the opamp (and series resistor) input noise at frequencies outside the
tuned circuit bandpass rather than being significantly enhanced as in
you circuit. The first opamp will ouput also be dc stable with a zero
signal output of around zero volts unlike your circuit.
This will do nothing for the rather large phase shift tempco, but at
least its a more rational design.
In fact your circuit performance should improve if you just delete the
first tuned circuit.
You still need to think about a suitable limiter that doesn't switch the
power supply noise to the output during stauration.
Bruce
-------------- next part --------------
A non-text attachment was scrubbed...
Name: ModifiedRawsonZCDInputStage.pdf
Type: application/pdf
Size: 5995 bytes
Desc: not available
Url : http://www.febo.com/pipermail/time-nuts/attachments/20070701/a25e45e2/attachment-0001.pdf
More information about the time-nuts
mailing list