Re: 180 degree phase shifter

Michael Black wrote:

Dirk Bruere at Neopax (dirk.bruere@xxxxxxxxx) writes:

Anyone know of any (simple?)circuit that will do a unity gain variable degree phase shift between 0-180 degrees? Frequency range is 0.1 to 100Hz.


The issue is that nothing simple will give you the phase shift throughout
the range.

So long as you are dealing with one frequency at a time, it's easy.
But if you need it to be broadband, and you do indeed state a broadband
need, it gets difficult.

Most wideband phase shifters used a bunch of them in cascade, and maybe
more important split the incoming signal into two channels.  By careful math,
the cascading phase shift circuits more or less work together, so throughout
the range it is more or less a 90 degree phase shift.  But we are
usually talking a 10:1 range.

Since you seem to be talking about variable phase shift, I think the
complication is infinitely worse.

If you are generating a signal, then you need to look at generating
both phase signals right out of the box.  Even if this is to shift
a  steady amplitude (and single frequency) signal that already exists,
some sort of PLL may be the easiest solution.

Beyond that, conversion to other frequencies may be in the cards.

Better to step back and explain the need, because too often people go
down the wrong path because they've jumped a step.

Well, the need is simple.
I am applying a signal to the senses eg audio/visual/direct electrical.
There are almost certainly delays associated with each mode of perception. If I want to eliminate those delays I have to apply different phases. Since I do not know those delays, and bearing in mind they may vary from person to person and according to time of application, a phase shifter is my first guess. I want the effect to hit the brains processing centres at the same instant, irrespective of nerve conduction rates.

--
Dirk

The Consensus:-
The political party for the new millenium
http://www.theconsensus.org
.

Relevant Pages

  • Re: 180 degree phase shifter
    ... >> the cascading phase shift circuits more or less work together, ... >> both phase signals right out of the box. ... >There are almost certainly delays associated with each mode of perception. ... If you want time delay, the amount of phase shift is linear with frequency. ...
    (sci.electronics.design)
  • Re: 180 degree phase shifter
    ... The issue is that nothing simple will give you the phase shift throughout ... But if you need it to be broadband, and you do indeed state a broadband ... the cascading phase shift circuits more or less work together, ... both phase signals right out of the box. ...
    (sci.electronics.design)
  • Re: Stability in Feedback Amplifiers, Part Deux-A
    ... Our amplifier is a three terminal device, ... Feedback is a scaled replica of the output terminal's ... The matter of phase shift has not been mentioned, ... And just how transient input signals behave with almost instant input ...
    (rec.audio.tubes)
  • Re: Intermediate Frequency
    ... implement it with rather complex mixers - which add much to the circuit ... signal (with a uniform 90-degree phase shift being applied to one copy ... two baseband signals to digital format, ...
    (rec.radio.amateur.homebrew)
  • Re: delays in XC95144XL CPLD
    ... ,,All similar signals travel through the same path in the CPLD, so ... It's very important that the signals must have the same delays but I'm ... clocks with an CPLD. ... capability of the output drivers in the XC9500 series. ...
    (comp.arch.fpga)