Questions tagged [phase]
For questions about AC phases (e.g. three-phase systems) or phase in the context of waves, transfer functions, etc. Consider using in conjunction with related tags such as "three-phase", "transfer-function", etc., as applicable.
367 questions
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Control Loop response of Buck Converters - Why?
In buck converters, control loop analysis involves injecting a small AC signal into the output feedback path to assess how the loop responds. This method helps evaluate the stability and dynamic ...
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0
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How to express the instantaneous current of each phase winding for a multi-phase motor?
I am working on an application of conformal mapping to the computation of the magnetic field in motors based on this paper, but I have trouble understanding how to compute the instantaneous current of ...
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58
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Bode Plot Analysis - Determine parameters
I'm designing a digital boost converter and need help analyzing this Bode plot. Could you please help me determine the following parameters:
Crossover Frequency
Phase Margin
Gain Margin
My conclusions ...
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2
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655
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What is the difference between line and phase voltage?
In a three phase system, I’ve heard line voltage described as the RMS of the voltage difference between two lines coming from the power source and phase voltage is RMS voltage of a particular line ...
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59
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Phase coherence problem between two RTL-SDR's (V3 & V4)
Im currently trying to acheive some rough phase coherence between two rtl-sdr dongles, the dongles share a single 28.8 MHz clock signal (from V4 to V3). However, there seems to be some phase drift ...
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3
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Why is the collector voltage of Q3 inverted in this differential amplifier circuit?
I’m working with a differential amplifier built with two NPN BJTs (Q3 and Q4, both MPSA06) and an active current source implemented using MOSFETs (Q1 and Q2, both BS170). The schematic is shown below:
...
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9
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Why do electrical engineers prefer "phase shift" instead of "time shift"?
Humans experience time, not phase.
Imagine the childhood game of message passing between a wire connected to two cups, one person talking at one end of the cup and the other person listening. The ...
2
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1
answer
176
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Oscillations in a transimpedance amplifier
I have been having a hard time understanding why oscillations are caused in a transimpedance amplifier (to clarify, I am just trying to understand the theory behind all of it)
Cin representing the ...
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3
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486
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Understanding Voltage and Current Phase Difference
I am having trouble understanding the concept of voltage and current having a phase difference in AC circuits. I have recently begun exploring AC circuits and have just started delving into the ...
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1
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78
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Need a simple circuit to do threshold tests against a 220V circuit being varied by phase-cut lighting dimmer
I am looking for a way to test to see if a phase cut dimmer on a 220V AC circuit is set to over a certain approximate percentage of full power, and use the output of that test to trigger a relay ...
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1
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214
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Flicker and Noise Floor
https://www.ti.com/lit/an/sbaa661/sbaa661.pdf?ts=1745596081730&ref_url=https%253A%252F%252Fwww.google.com%252F
This document talks about the impact of slew rate of reference source on PLL. Few ...
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104
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Circuit for voltage controlled sawtooth phase shifting (0 to 360 degrees)
I'm looking for an analog circuit that can phase shift a sawtooth wave from 0 to 360 degrees.It needs to work with frequencies from say 1 Hz to 20 kHz.
I found one here https://modwiggler.com/forum/...
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1
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103
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Weird phase shift values even for simple circuits in LTSpice
I simulated some complicated circuits to solve why an oscilator is not oscilating (strange Murphys law - emitter follower is oscilating, but oscilator not :)) ) and still had a strange phase shift ...
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1
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PMU vs PLL in power system
I have been reading a lot about power systems lately, and am confused regarding the difference between phasor measurement units and phase locked loop? Firstly, are they different. PMU as I have read ...
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81
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Old single phase motor
I am trying to figure out how to wire this old Stayrite 3hp single phase motor. I have attached a picture of the terminals but that’s all the info I have. I am not sure if there is a capacitor ...
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3
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372
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Phase shift of high-pass L-R circuit extremely off at low frequencies
I am testing a high-pass (HP) \$L-R\$ series circuit. My inductor is 33 mH, and the resistor is 1200 ohms. The phase shift of my \$L-R\$ HP circuit should be \$\tan^{-1}(6200/f)\$ -- this works until ...
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2
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140
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How the derivative of voltage (v = Vₘ sin(ωt + φ)) becomes jωV in phasor domain?
I'm reading sinusoid, and I don't understand where does the Euler's "e" go while transforming it from time domain to phasor domain.
How do we get equation (9.27) from equation (9.26) below?
(...
2
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1
answer
74
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AC high current PCB traces
I'm making a circuit that rectifies ( full wave ), with a center tap transformer. Here is my design:
As you can see, I want to control the sinusoidal with SCR phase control.
My concerns are because ...
2
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2
answers
540
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How is 460/230V 3PH mains possible?
I'm making a piece of machinery for a customer in Mexico, and they insist that their mains voltage is 460V between phases, 230V between each phase and ground, 3P-N-PE. Only if this was a split phase ...
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4
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233
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Unclear phase stability condition for oscillation
Does anybody know how this condition for oscillation (equation 1.2) can be derived mathematically and/or explained intuitively? I feel like this equation has something to do with the Nyquist plot of <...
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127
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How to phase shift two complementary PWM signal using stm32f401rct6 black bill?
I am using STM32F401RCT6. My application is to drive a phase shift full-bridge DC converter, for which I require two pair of complementary PWM signals with dead time insertion, and not the same center ...
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2
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446
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Why my sinewave get distorted when it is 10MHz and above
I am generating an analog sine wave with different frequencies. However, when the frequency is higher than 1MHz, it gets distorted.
This is how 10MHz sinewave looks like
This is what I see when stop ...
3
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2
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177
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Calibrating phase shift of multiple RF circuits
My situation: I have a 16x antenna phased array with each antenna connected to its own receiver pre-amplification circuit that I have custom made. Since the system is a phased array, the phase shift ...
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0
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Reversing 2 speed 575/3/60 motor phase loss detection
What device can be used to detect phase loss (or blown fuse) on a 575/3/60 reversing 2 speed motor that has high speed and slow speed fusing?
3
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3
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701
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PLL in Phase lock but not at 0 degrees
I have a PLL that is meant to synchronize a VCO to a reference signal, but the VCO is 90 degrees out of phase with the reference. How can I fix this to be precisely in sync with the reference signal?
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1
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157
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Can LTspice express the result of a phase measurement in degrees?
I will ask my question through the following example to make it simpler.
I have the following directive to find the minimum phase value:
...
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1
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0
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55
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Obtain phase spectrum from frequency/phase modulated signal
I have a homodyne rf setup in which I measure spectra by stepping frequency by frequency. The phase reference resets every time I change the signal frequency, so I can only measure the amplitude, but ...
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4
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8
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Can't the electric current returning from the neutral end of the electrical cables be used again?
I am someone who has little knowledge about electricity, but I have something I am curious about. I could not find the answer by searching on the internet.
If the electric current comes from the phase ...
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1
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269
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Transformer Input Wiring Question
I apologize for the basic question, but I just bought a transformer with the following specifications. On the input side, there are two black wires and two red wires. Here is a photo.
And here the ...
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2
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470
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My extension show live in all connections when off [closed]
I yesterday bought this new extension and was using for some pi stuff - that's when I noticed small current in pi even though its switch is off.
When I tested it with tester, here's what is happening
(...
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0
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124
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SCR Power Controller (Phase Angle Firing) with Silicon Carbide (SIC) Heating Elements
I’m working with a 3-phase (208V) SCR power controller (Watlow Power Series) operating in Phase Angle Firing mode with current limiting set to 80A. The setup involves two pairs of silicon carbide ...
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1
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140
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Active RF signal repeater
I have two stations, A and B.
Station A broadcasts a pure 10MHz sinusoidal signal on air. A ...
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0
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98
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Need Help with DIY Phase sequence meter
I have seen this video: https://www.youtube.com/watch?v=HyrhW_gnQEM and I am really interested in creating DIY version of this for induction motor. Surfed through internet, but could not anything ...
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1
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I have so many questions about this method of grounding in this video? [closed]
https://www.youtube.com/watch?v=G8JgS-STozA&t=537s
First, I apologize this video is in a different language, but I'll point out what is relevant.
So, in this video. There is a man saying that his ...
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1
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Does the center tap of a single phase distribution transformer get bonded to the grid neutral? [duplicate]
Here are the two wiring diagram.
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2
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226
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Is this how a single phase transformer is connected to multiple houses? [closed]
Single phase transformer serving 3 houses:
I am not sure if this correct. Can someone confirm?
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3
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Why do some op amps' datasheet specify phase margin at open loop?
I am not able to understand what significance phase margin would hold in case of open loop. Shouldn't it be just phase? If it was loop gain I'd understand specifying phase margin to denote stability. ...
0
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0
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74
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What options are there for multiplying clock pulses by non-harmonic values?
I have a MIDI clock signal which will output pulses at 24ppqn and a device I would like to synchronise which runs at 64ppqn. This is equivalent to a an ⁸⁄₃ clock multiplication.
My current method is ...
1
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1
answer
85
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single phase into vfd
I have a three phase in three phase out vfd which is rated for 230V. I would like to use it to power a three phase motor. The manufacturer of the drive states it will run from a single phase input, ...
1
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1
answer
618
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Is a high-amp car alternator three phase or single phase power? (12 V, 150 A machine)
I am in mechanical engineering, and have only worked with three-phase power. I modeled a 12V, 150A car alternator as a three-phase electrical machine simply based on when I look up what most ...
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4
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234
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Conceptually, what is phase?
I get it mathematically and how it shows different waveforms in relation to each other on a graph but I am struggling to understand the real world significance and the implications. Like I hear people ...
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1
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379
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Determine AC Motor wiring (again)
I have this air extractor which has an AC motor with multiple speeds.
It has 4 wires (Yellow, Black, Blue, White).
I know for sure that the yellow wire is connected to the LIVE on AC 220V
It has a ...
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0
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Whats the meaning of Im, Is and Ih
I would like to know what's the meaning for the abbreviations of Im, Is and Ih in leakage currents measurements, as it is depicted in these graphis. Could anyone help me?.
The link of the source is: ...
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3 phase motor, star wiring, neutral
Consider a normal 3 phase motor with star/delta, focusing on the star wiring here... what would theoretically happen if I placed a neutral wire from the star connection contactor, to the electrical ...
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6
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How can current phase shift be 90 degrees behind voltage just "inside the capacitor" on an RC series circuit but be in phase in the resistor?
Imagine an AC source in series with an RC circuit.
In this video, the instructor claims current will be 90 degrees behind voltage inside the capacitor but not inside the resistor or the whole circuit. ...
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2
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2
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579
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Phase modulation for binary data - higher frequency harmonics?
I've recently learned about PSK and QAM. I first came across it in this youtube video (timestamped), and my understanding for how it works has remained the same as what is shown in that video. (I also ...
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1
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268
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SCR phase control
I'm making a battery charger with phase control. While making the circuit I had some doubts.
The transformer has a center tap, in this way I can make a full wave rectifier without diodes. Then ...
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1
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441
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TCA785 obsolete, replacement? [closed]
I am looking to redesign an old circuit diagram's phase control IC. I can't find any ICs that can act as a replacement for this item:
TCA785.
What should I look for in an IC for phase control? It is ...
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2
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137
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Which of these connections are incorrect and why? [closed]
Is there a difference in these connections and is there anything wrong on any connection? I am new to phase and neutral wiring. Kindly help me.
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3
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Phase difference between voltage across a capacitor and the source in a low pass filter
Consider I have a low pass filter like that in the figure.
simulate this circuit – Schematic created using CircuitLab
I have considered the voltage source to be \$V\$ and the voltage across the ...
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