Delaying a signal 180 or 90 degrees

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Discussion Overview

The discussion revolves around methods to delay a sinusoidal voltage signal by 90 or 180 degrees. Participants explore various approaches, including analog and digital solutions, while considering the implications of different components and circuit designs.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant suggests using capacitors or inductors in parallel with the voltage source but notes that these components primarily affect current rather than voltage phase shift.
  • Another participant proposes a digital approach involving an A/D converter to determine the signal period, followed by a digital delay and a D/A converter.
  • A later reply confirms that adding a capacitive load to a voltage source does not affect the amplitude or phase of that source with an ideal source.
  • It is mentioned that filters can change both phase and amplitude, with a suggestion to use low-pass RC filter sections to achieve a combined delay of up to 180° at a specific frequency, noting a typical lag of 45° per RC section.
  • Another participant points out that there are filters designed to provide phase shifts with minimal amplitude change, although they can be complex and require precision components.

Areas of Agreement / Disagreement

Participants express differing views on the effectiveness of various components and methods for achieving the desired phase delay, indicating that multiple competing approaches remain under consideration.

Contextual Notes

Participants acknowledge that different frequencies will experience varying delays with the proposed circuits, and the complexity of achieving precise phase shifts without amplitude alteration is noted.

Rectifier
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Hey!
How can I delay a sinusodial signal (voltage) 90 or 180 degrees?

I have been thinking of a capacitor or an inductor in parallel with the voltage source but these components do not impact the phaseshift of the voltage but the current.

Can anyone help me please?

EDIT:
I know that there are other solutions to simple sinusodial signals like just inverting the signal but I am searching for a more complex solution.Sorry for my bad English.
 
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The digital answer: Run the signal through an A/D converter, determine the period, do a digital delay, run it through a D/A converter.
 
Rectifier said:
How can I delay a sinusodial signal (voltage) 90 or 180 degrees?

I have been thinking of a capacitor or an inductor in parallel with the voltage source but these components do not impact the phaseshift of the voltage but the current.

Can anyone help me please?

EDIT:
I know that there are other solutions to simple sinusodial signals like just inverting the signal but I am searching for a more complex solution.

That is correct: adding a capacitive load to a voltage source cannot affect the amplitude or phase of that source, with an ideal source.

Filters are circuits which cause their output to be changed in both phase and amplitude, relative to their input. You could connect in series a few low-pass RC filter sections to get a combined delay of up to 180° at a given frequency. As a rule of thumb, work on 45° lag for each RC section. A consequence of this form of passive filter is that it attenuates the amplitude at the same time as providing a delay. Of course, different frequencies will undergo different delays, with any given circuit.

There are filters which deliver a phase shift with almost no change in amplitude over a wide band; these can get complicated and to perform the feat demand precision components.
 
NascentOxygen said:
There are filters which deliver a phase shift with almost no change in amplitude over a wide band; these can get complicated and to perform the feat demand precision components.
For example: https://en.wikipedia.org/wiki/All-pass_filter.
 

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