# Questions tagged [impedance]

Impedance defines the voltage/current characteristic of any dipole circuit.

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### Electrical circuits homework

I am pretty new to circuits analysis and I have the following problem as homework: ig2(t) = 4sin(ωt + π/4), e3(t) = 12sin(ωt + π/4), R1 = 10 Ω, ωL1 = 4 Ω, ωL3 = 3 Ω, 1/(ωC2) = 6 Ω I have to calculate ...
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### Connect speaker directly to Samsung Galaxy S6. Minimum impedance accepted

I want to connect an external (passive) speaker (3W/16 ohm) directly to my Samsung Galaxy S6 using the headphone jack. I want to do this on my bicycle using the smallest space possible. Connecting the ...
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### Why the capacitive divider in this output stage?

I have this output driving stage, reverse engineered from a generic Chinese mist generator: The goal is to drive the piezo transducer with a given frequency (more or less 1.7MHz or 2.4MHz depending ...
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### Common term for Resistance and Conductance?

Simple question; Impedance and Admittance are complementary quantities, and can be described by the common term "Immittance". Likewise Resistance and Conductance are complimentary quantities,...
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### Differential and single-ended input impedance

I have this circuit and I'm interested in finding both the single-ended and differential input impedance. But is there even a difference? This is also at DC, so we can just ignore the inductors and ...
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### Locally hatched ground plane to increase differential impedance

I am designing a flexible PCB to carry two types of differential signals. One is about 1.2Gbps 100R differential impedance, while the other is only 3Mbps, with much more tolerance on the impedance. ...
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### Low-pass filter - choosing R values dependent on the load impedance

I need to design a low-pass RC filter that is connected to an oscilloscope at the output. The oscilloscope has a load impedance of 1MΩ||20pF. I have to choose values for R and C, taking this load ...
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### Circuit Analysis: Difficulty in obtaining a current through a resistor?

I'm solving a problem that requires I compute some impedances, and then the current through a resistor. I obtained some of the impedances*, but don't know how to get the second part (current). ...
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### How does at low power factor impedance (p.f=R/Z) (if R is constant ) increases while current also increases?

Impedance is equivalent resistance of circuit having resistive and reactive components so if we keep R constant and increase inductance than Z will increase and power factor will going to decrease as ...
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Admittance is the reciprocal of impedance. But: 1) Susceptance is the reciprocal of reactance, or the imaginary part of admittance ? 2) Conductance is the reciprocal of resistance, or the real part ...
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### Output impedance of a series shunt feedback amplifier

I am trying to find the output impedance of a series shunt feedback amplifier by converting it to a two port network. I know the input impedance: Ri=ri*(1+A.β) But I dont know how I should find ...
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### Calculating the off impedance of a relay output by a multimeter

I'm trying to calculate the output OFF impedance i.e. the impedance caused by its RC snubber of this SSR. So I perform the following test: Zc is the relay's OFF impedance and Zv is the fluke 114 ...
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### Does transformer line side voltage varies with backup generator on load side running at from 0 to 100%?

We have a transformer of 750 KVA with 5.75% impedance. On the load side we have loads and a back-up emergency generator. This emergency generator is capable of supplying the loads and still export ...
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### Twisted pair with shield and drain wire

Ive been posed with a problem regarding calculating the characteristic impedance of a shielded twisted pair with a drain wire. While I understand how to calculate this for a "normal" shielded twisted ...
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### Inferring common mode impedance for a given CMRR

In the figure below, the common mode impedances of the line driver and receiver are represented by RCM+ and RC-: (What I understand by the phrase CM impedance is that it is the resistance or ...
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### Dipole Antenna impedance and feed point, what is the effect of long distance to coax connector?

I have a folded dipole being made with a pair of twisted wires where each wire is 1/4 λ long and the dipole is constructed by twisting the centers of the wires so that the twisted pair is ...
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### Low-impedance tap in this oscillator circuit

Here is the schematic of Michigan Mighty Mite, a popular transmitter circuit design. It seems to be quite close to a regular feedback oscillator, with a few peculiarities. What puzzles me is the ...
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### ngspice .measure syntax in AC + par()

Why do the two netlists give totally different output impedance values ? Netlist 1: ...
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### Do Germanium BJTs have lower impedance than Silicon BJTs?

What brings this up is the fact that Germanium has a higher electron mobility than Silicon(as well as lower barrier potential) and does that translate to greater admittance(including susceptance)?
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### How do I refer an impedance from the delta side of a transformer to the WYE side?

My question is regarding the simple arrangement below: It is simply a three phase source feeding a load through Z1, followed by an ideal WYE DELTA transformer, followed by Z2. My question is how do ...
319 views

### Impedance mismatch in LISN for EMI/EMC test

I am currently designing LISN for CE-102 test.The schematic of the circuit is provided below. When I connect the circuit to the network analyzer the impedance is coming as shown below expected graph ...
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### Need fast and exact voltage follower or divider cascade

Intro: I'm designing a makeshift oscilloscope and now need an input cascade for it (it is more fun project for me, rather than industrial-grade tool). The matter is I want to get something faster ...
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### 6 SPEAKERS one amp

I just joined stack exchange to ask this specific question. I have 6 speakers. All 6 are 8 ohm speakers. There are 2 pairs (Speakers 1&2 are pair A and speakers 3&4 are pair B and then 2 ...
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### Ouput impedance of a balun

I am using the CC1110 RF IC and I am having trouble when matching the differential RF output impedance with the antenna. The datasheet states that the differential impedance seen from the RF output ...
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### When are positive-sequence and negative-sequence equivalent impedance the same?

One of the topics we covered in an introduction to power systems class was using zero/positive/negative sequence networks to analyze faults in networks. For many problems, this requires setting up ...
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### Antenna VSWR value and impedance matching claims by the manufacturer

Having larger value of VSWR is indication of improper matching. Eg. http://www.abracon.com/patchantenna/ACA-107-T.pdf this datasheet claims VSWR to be around 4:1 to 5:1 (which seems bad VSWR value to ...
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### Differential impedance calculation: reference plane doubt

I'm calculating the width and spacing for my differential signals to meet impedance requirements. I have downloaded Saturn Impedance Calculator for making calculations. My pcb stackup has embedded ...
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### How do I convert S-parameters for impedance matching?

How do I derive the Z-parameters to calculate a matching network for a device? I'm not sure what terms to even search for as I get all sorts of information I am not familiar with. My task is to ...
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### What can I do to avoid impedance discontinuity when high-speed signal bifurcates on PCB?

As mentioned before, I want to supply two PCBs with same-frequency clock(as high as 10GHz).But now there is only one pair of differential clock, while both of the PCBs need one. So I am thinking of ...
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### Without converting the secondary side to “Y”, how would one solve this question?

The question: "A three-phase 230 V, 27 kVA, 0.9 PF (lagging) load is supplied by three 10 kVA, 1330/230 V, 60 Hz transformers connected in Y-Δ by means of a common three-phase feeder whose impedance ...