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

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AC-coupled RF Microstrip routing over power plane

If I route a 433 MHz AC-coupled RF microstrip trace out of an MMIC such that it's referenced to a Power plane rather than a Ground plane, will that have a significant effect on the impedance of the ...
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61 views

Output impedance of voltage divider?

When connecting a 10S LiPo (42V) to my ADC via a voltage divider, I began wondering how to calculate the output impedance of the divider. simulate this circuit – Schematic created using ...
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33 views

Calculation of Open loop differential gain and open loop output Impedance

I want to calculate the open loop output impedance and open loop differential gain of a discrete differential amplifier (Figure attached). Is this feasible? Here is the approach. INPUT STAGE: ...
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1answer
48 views

Effect of metal resistivity on the characteristic impedance of microstrip line

We know that the characteristic impedance of a microstrip line is given as follows: In general the metal resistivity is so small that Z0 can be taken as sqrt(L/C). But if the metal resisitivity is ...
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67 views

Impedence of 90° out of phase Capacitor and Inductor in parallel

I'm curious as to what the equivalent impedance would be of these two elements. Mathematically it seems that they would have infinite impedance (meaning an open circuit), but this doesn't make any ...
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92 views

Transfer function of R and C parallel

Currently I am learning control systems. I specifically find the mathematics very hard to understand. For my exam I am practicing on this question: "Determine the transfer function of this circuit in ...
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40 views

The equation op amp output impedance

Tell me please. How to describe the dependence of the equation output impedance AD8510.
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1answer
89 views

A question about the argument part of impedance

The definition of impedance is Z = V/I. I'm trying to understand the idea behind the argument part of the impedance concept in a capacitor. First here is what I know briefly so far: I will begin ...
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1answer
44 views

Difference between 32 KHz clock output load vs. clock input impedance requirement

I have a WiFi chip that requires a input impedance of > 100 kohms and < 5 pF as seen in the requirements table found in the datasheet below. I'm confused if this 5 pF requirement correlates to ...
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57 views

Circuit to measure impedance

I'm trying to make a circuit to measure impedance through a FRDM-KL25Z board. The basic idea is to use two signals to calculate the phase shift between them, and use a impedance divider to calculate ...
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44 views

Calculating true power of a predominantly inductive load?

I'm stuck at this problem, which doesn't seem to be so difficult, but, I guess there is some basic stuff that still confuses me. So, if we have a load represented with complex impedance \$Z=30+j40 \ \...
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43 views

transfer function of a complicated circuit

How to find the transfer function of this circuit? The addition of C_1 and another input function v_2 makes it more complicated Is it: \$Zout=\dfrac{R1}{1+R1C2s}\$ \$Z0 =\dfrac{1}{C0s}\$ \$Z1 =\...
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37 views

Reflections on a differential transmission line

I understand why reflections occur when there is an impedance mismatch on a single-wire transmission line. However, when we introduce a differential line, I am having trouble picturing what would ...
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71 views

Wy are speakers rated by impedance instead of inductance?

Audio speakers contain coils which product sound by vibrating a cone. Why are speakers rated by impedance instead of inductance?
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30 views

L293D Motor driver 'braking' using input pins

I read the following on Wikipedia: Using pins 2 and 7 ( 15 and 10) to determine motor START/STOP or PWM duties it's dangerous, since there wouldn't be high impedance outputs: Current would flow ...
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22 views

Does the absolute sum of the elements of the imaginary part of the Y-matrix correspond to anything?

I have a simulation of a device with 4 ports (a double gated organic field-effect transistor), about which I also have some experimental data. I also made a simulation where I extracted the impedance ...
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19 views

Different Op Amp output for battery/usb power

I'm using a micro running arduino to measure the resistance between two electrodes, connected to a dual op amp with automatic feedback control bias. The output is accurate when the circuit is powered ...
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1answer
35 views

Impedances to simplify RC circuit?

Suppose I am trying to solve the following circuit, where \$V_i\$ is the potential seen from the top branch to the bottom branch (which is 'grounded') and \$V_o\$ is the potential across \$C_2\$: ...
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104 views

How to calculate the output impedance of this circuit?

This is a hybrid-pi model of a BJT, and I want to know its output impedance: simulate this circuit – Schematic created using CircuitLab I know that I should short the input ports, place ...
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38 views

can the inductor and resistor values be found from the impedance

If the inductive impedance is given can the separate resistor and inductor values be calculated? OK The question gives the voltage supply (magnitude and frequency), power factor and current. It ...
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45 views

Input impedance of audio amplifier, unclear from datasheet

I have a AN7190NK audio power IC. It is a amplifier for the car radio. I want to know it's input impedance. In datasheet it states that: Input impedance ZI VIN = ± 0.3 VDC 28 kOhm I don't really ...
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28 views

Output Impedance of circuit

Please see image. Should'nt the output resistance be Rout = ro1 || ro3 rather than just soley ro3?
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35 views

Input power with PF, impedance on transmission line and transformer

I've just had and exam (Renewable Energy) and we had a problem that I'm not sure if is correct. The answers should be simple as we haven't studied tranmission lines at all. Okay, here we go. We have ...
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64 views

Impedance phase angle relative to?

In a simple PARALLEL RC circuit with two components of Resistor 150 Ohms and Capacitor 0.000000075F (75nF). AC supply 10V at 20,000Hz. Impedance has a phase angle of -54.7 degrees if my calculations ...
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68 views

Build own custom USB 'regulator' adapter board to solve Desktop boot hangs with KVM

My Desktop PC hangs in the BIOS boot phase when my KVM is attached. If I unplug the USB connecting the PC to the KVM, the PC boots without hanging. If the USB of the PC is connected directly to the ...
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88 views

Why is a shielded cable not effective with high impedance sensor?

Could some one simplify what this means? Why is the shielded cable not effective with a high impedance source/sensor?
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61 views

Impedance matching for piezo element

I am trying to boost audio signal from around 3V to around 60V for a piezo element with a component as small as possible. I found audio transformer MET-23 that reflects 1.6 kOhm impedance on primary ...
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67 views

What resisters for inverting op-amp should I use?

I am not an electrical engineer by any means so go easy on me here. I am simply experimenting with a speaker amplifier. My situation: I have a Clarion xc1410 4-channel amplifier with a 10k input ...
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45 views

Power calculation and Ohm's Law for Reactance

Hi I have the following question: V = 120V, I = 10 A, I lags V by 60degrees simulate this circuit – Schematic created using CircuitLab The load consists of a resistor and an inductor ...
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53 views

Circuit completes whether base current applied or not - transistor

My fourth electronics project ever. The most challenging yet. I've wired up this project (Project 4 - Short Circuits project kit Jaycar Electronics). After much research, it doesn't do what I ...
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58 views

Finding impedance Z and \$ \cos (\alpha) \$ in RLC circuit

I would like to have some help with this problem: U = 93 [V] f = 600 [Hz] L = 0,24 [H] C = 0,16 [μF] R = 950 [Ω] This is the RCL circuit which I need to find the impedance \$Z\$ in and \$\cos(...
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109 views

This guitar piezo opamp buffer lacks any sort of bass, why?

My preamp in my acoustic guitar died after I put the battery in backwards. I need to replace it, and fast. Piezos have incredibly high output impedance (5+ mohm) so a buffer circuit is used to knock ...
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1answer
73 views

Understanding Ohm's law(?) for transmission lines

I have this easy schematic Next to this is stated that: $$Vb = \frac{Z_{in1}e_{b}}{R_{B}+Z_{in1}}$$ non Latex-version of the formula: Vb = (eb*Zin1)/(Rb+Zin1) I would like to know from where ...
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105 views

Set ADC input to high impedance

On a early version of the system I'm working on, an Arduino Mega was being used to read some analogue values using its ADC. Something critical to the application was for the ports to be always in high ...
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51 views

How to make an impedance matched circuit for fabbed antenna?

Okay I have developed an antenna for a system and need to create an impedance matching circuit. The theory of conjugate matching is simple, but actually implementing it is something I can't find ...
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34 views

Impedance Spectroscopy - Modelling a physical system as an RC network

I have a physical system which can (in principle) be modeled as a network of resistors and capacitors. To extract values of components, I am doing a frequency sweep and Fourier transforming, and ...
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33 views

Proof of formula to convert from parallel to series impedance

So, I tried to find a proof to the formulas to convert from parallel to series reactive circuit, which I found in the ARRL Handbook: \$R_s=\frac{R_pX_p^2}{R_p^2+X_p^2}\$ and \$X_s=\frac{R_p^2X_p}{R_p^...
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51 views

Is this measurement of a cricuit's output impedance valid?

The following circuit is a simple voltage regulator. The Vout is maintained at -1V, however the opamp in the circuit has a non-zero output impedance. This is represented by the resistor R1. ...
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55 views

Power at the differential output

I was measuring the voltage at the intermediate frequency output of this tuner http://superkuh.com/gnuradio/R820T_datasheet-Non_R-20111130_unlocked.pdf using the oscilloscope. The tuner has a ...
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294 views

What does impedance control on a PCB mean [closed]

I understand that when the electrical length is less than 1/10 of the trace length I would have to go in for impedance matching. A PCB impedance is controlled by its stack up. THat is thickness of ...
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50 views

Getting the numerical value of a capacitor's impedance

I understand that the impedance of a capacitor is \$\frac{1}{j\omega C}\$. For the circuit above, I have \$\frac{1}{Z_V} = \frac{1}{Z_{V1}} + \frac{1}{Z_{V2}} + j\omega C_V\$ and \$V_V = \frac{Z_V}{...
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84 views

Input/output impedance of microcontroller

how to calculate the input and out put impedance for a micro controller , for the purpose of modeling in LT spice , for example RX610 family from Renesas For example the lumped characteristics can ...
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1answer
53 views

Calculating Thevenin impedance

This is the circuit I'm given: And after disabling all of the sources, I'm now trying to calculate the equivalent impedance (which would be the Thevenin impedance): But I'm stumped on how to ...
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1answer
52 views

Impedance matching photon detector with multiple TTL counting devices

For my scientific work I wish to register signals coming from a photon detector which generates 50 Ohm TTL signals: The expected count rate will never exceed 4 MHz. The devices that need to record ...
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1answer
84 views

Is it practical to measure an unknown capacitance by measuring its impedance?

I've recently seen some fourth year engineering projects at my school (University of Waterloo) and one that I found interesting was this novel pressure sensor that uses nano silver separated by a di-...
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1answer
59 views

PCB Trace Differential Pair Impedance

I'm designing a MIPI D-PHY interface, and the required nominel trace impedance for the differential signal lines (pcb traces) are 100 ohm. Can I create 100ohm differential impedance, by using two ...
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105 views

Measure AC power consumed by a loudspeaker

I'm interested in measuring the efficiency of a loudspeaker. I have tools to measure the SPL in dB. However, the electrical efficiency has me a little puzzled. The speaker has a voltage applied: \$...
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70 views

Looking for a general, rigorous definition of “impedance”

Forget capacitors. Forget inductors. Forget resistors. Assume a generous background in elementary complex analysis and algebra. I'm trying to arrive at an elegant, minimalist, mathematically ...
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53 views

Physical interpretation of Re(Z) = max(Re(Z)) and Im(Z) = 0

I have plotted the real and imaginary parts of a device's input impedance with a VNA. What would be the best physical/electrical interpretation of the real part peak along with the imaginary part ...
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327 views

When do you need impedance matching?

Would anyone please explain why you don't need a controlled impedance board when you produce a PCB dealing with 50Mhz digital signal? I thought you might need a controlled impedance board, since 10Mhz ...