Impedance Definition and 507 Threads

Hi, I'm having a little trouble understanding the concept of impedance matching to maximise energy transfer. I understand that the reactance of a capacitor is X_c= \frac{1}{\omega C } and that it is always 90 degrees lagging of the current in the complex plane which leads to a capacitors...

Im tryin to figure...In a circuit having a parallel resistor and inductor, as the applied voltage frequency increases, the total impedance...increases?

I'm basically looking for something like Sonnet which performs well at low frequencies. I'm trying to investigate the impedance of different shaped traces at frequencies of around 1 - 20 kHz. At such low frequencies, Sonnet's response data is usually garbage. The trace under...

Homework Statement A 2.80-k W resistor and a 4.60-mF capacitor are connected in series across a 46.0-Hz AC generator. What is the impedance of the circuit? Homework Equations Z = sqrt ( R^2 + (XL -XC)^2) Xc = 1/wC = 1/ 2*pi*46.0 Hz* 4.60uF XL = wL The Attempt at a Solution...

Homework Statement Can anyone tell me what input impedance is? The context is "...these two solenoids act as a transformer. An AC voltage Vexp[jwt] is placed across the first and a resistor R across the second. Show that the input impedance of the first solenoid is equivalent to a circuit...

Homework Statement http://img297.imageshack.us/img297/2951/picqk5.th.jpg I'm just trying to do part a for the moment. Homework Equations The Attempt at a Solution My initial attempt was just trying to find the impedance of the 5 mH inductor and saying that would be Zin...

A friend of mine is having problems with a measurement signal he is getting from a Rogowski coil. When he changes the coaxial cable length the amplitude of the signal changes. It’s been a while since I’ve studied this type of thing but to me it sounded like an impedance mismatch issue and...

So the power is S=VI*=ZI^2. the question is whether V=ZI* or just ZI. Using V=ZI when I calculate the voltage i get a negative answer. Thanks!

Hi, I have designed and built my own impedance spectroscopy instrument, using a lock-in amplifier approach, with a reference signal. I know the basic theory behind impedance and impedance spectroscopy. However, I would like some thoughts on experimental set-up. I have a reference source...

Homework Statement Homework Equations The Attempt at a Solution Hi all, i have some doubts on how to find the impedances for active filter circuits. Let's start with a simple low pass filter : http://img85.imageshack.us/img85/6484/52244578oo4.th.jpg The input impedance should be...

I have trouble figuring out how my textbook came up with the totals and am looking for step by step help. Here is what the text shows. Z = R + j0 = R = 56 Ohm (in rectangular form [XL = 0]) Z = R < 0 degrees = 56 < 0 degrees Ohm (in polar form) Z = 0 + jXL = j100 Ohm (in rectangular form...

hello I have a problem in calculating the equivalent impedance of a simple AC circuit, where the impedances are: Z1 = 5+i20 Z2 = 5+i20 Z3 = 10-i2,5 Z4 = -i10 Z5 = 5 and I need to find: Z_eq = Z3 // [(Z1 // Z4) + (Z2 // Z5)] where the + indicates 2 components in serie...

hi i have one quiry related to input & output impedance of any circuit? generally for cascading we expect High Input impedance & Low output impedance to avod loading effect? But what is loading effect ? exactly what happen to current & voltage when loading ouucures ? how this theory...

hi, I have tested impedance of transformer coil and I found out that if I would like to have smaller input impedance then I have to reduce the diameter of magnetic wire. I understand that If i reduce the cross setion of the wire then I will reduce the DC resistance. I don't understand...

High Impedance in Verilog? Homework Statement Provide the correct Verilog text for encoding the following numerical values: A) A 16 bit hexadecimal with all positions in the high impedance state: B) An unsized hex number BEEF Homework Equations Verilog Problem. There is no...

Hi. I need to connect an antenna to a BPF (Band Pass Filter) and this one to a transceiver. The BPF purpose isn't to make matching, is to filter the input/output signals to the desired bandwidth. I'm a little confuse and would like you to confirm my ideas, to help I made a sketch...

Homework Statement Homework Equations I know that at low frequency the capacitor will act like an open circuit. However, i do not know what is meant by input impedance, does this just mean the combined impedance of the components in this circuit? The Attempt at a Solution Assuming it is...

Could someone please help me out with this question, I can't find it everywhere in my book. Its a question I need to know for my exams as well. Q. Distinguish between reactance, resistance and impedance and illustrate their relationship on an impedance phasor diagram.

I know the formulas, to some extend what impedance is. But i guess i would like to know what it really means in real world and how to use it/match it or manipulate it. Please help correct my understanding or increase it. :) High impedance is like high resistance and vice versa. You want...

I know the impedance of a capacitor is, \frac {1}{j \omega C} so in an audio circuit it let's more high frequency energy through, which is obvious looking at the equation. When a capacitor is in parallel with a fixed resistor, I worked out the magnitude of the impedance of the pair to be...

Our professor gave us some homework and one of the problem statements reads: "Design an impedance matching network used to connect a 300 Ohm transmission line to a 50 Ohm transmission line." Is this as simple as Zmatch = Sqrt(Z1*Z2) ? I'm wondering if there's something I'm missing...

He insists they are synonymous. I said I didn't agree. I told him that impedance is specifically the ratio of voltage to current in the s-domain or frequency domain. Impedance carries much more information that resistance alone. Is it technically correct to think of impedance as being the...

Homework Statement First of all, sorry the poor quality of the drawing... lol made on paint! Anyways here is the problem and all given data : The capacitor model we have used to far has been treated as an ideal circuit element. a more accurate model for a capacitor is shown in figure 4.67 (...

Homework Statement This is a general question regarding impedance in circuit analysis. I know that in order to find the total impedance of a circuit, you transform each element characteristic into the frequency domain, i.e., R\rightarrow Z_R = R, C\rightarrow Z_C = \frac{1}{Cs} ...

Homework Statement I'm working a problem where I have a j8ohm and a -j8ohm in parallel, and I need to reduce the circuit to get the current in one of these branches. Being these numbers, I get a fraction with zero on the bottom. How should I treat this? The Attempt at a Solution I'm...

Why is the coaxial cable impedance independent of it's length? I am considering the model shown in the attached picture. Since the resistance, capacitance and inductance are all dependent of the length of the cable in one way or another how come the impedance is not? I also can't find any...

ac impedance ...find power this is the circuit...attached...i have to find appartent power ( S) , Average Power (P) and power factor (p)...i have tried this question a lot times but every time i get incorrect result ...please solve this question... Thanks

Hi all, I'm stuck on this part of a problem. I have gotten the net impedance between two terminals A and B. The impedance I got was Z=8.39+2.22i Now the question is... The network is equivalent a to a resistor and an energy storage element connected in parallel. Find their values. I...

Can anyone tell me what is the relationship between the actual line impedance with the zero sequence impedances and positive sequence impedance? Let say I have the zero sequence impedance=0.15+1.79j positive sequence impedance=0.013+j*0.32 what is the actual impendance? In real...

Impedance and Frequency- directly or indirectly related? I think it's inversely. Am I correct? Let Impedance =Z p==pressure v=velocity Z = p/v and v=f(lamda) So Z= p / (f(lamda)) Isn't Impedance inversely proportional to frequency?

I am trying to come up with a way to monitor a device that alarms. The signal is open collector: high impedance when not alarm. I would also like to be able to connect this to a computer and monitor and log the alarms when they happen. Any help would be greatly appreciated.

The vacuum impedance,as our professor writes in blackboard, equals 377 ohm What is the physical origin of this impedance?

Hi! I am trying to measure the voltage through a "DaqPro", basically a data logger. I've used a voltmeter to get a reading, but then when I use the DaqPro it's totally off. So my question is--what does loop impedance mean, especially if it reads: (Input Channel Measure: 0 – 50.000 mV)...

I'm trying to model a circuit. Part of this circuit is a guitar amplifier. I don't know what kind of circuitry is inside the guitar amp, it manufactures often list the input impedance in the product specifications. When they say input impedance, do they mean the impedance between the...

see diagram http://img.photobucket.com/albums/v11/biggm/z.jpg The question is to find the equivalent impedance for the circuit. I am not sure how to solve this, it is simple in the case of all three elements in series but with the capacitor in parallel i am not sure how to solve it...

question. One of my HW problems asks the following after you solve it. Tell if the impedance is complex inductive, capactive, or real resistive. I said if my answer is of the form, R + 0j it is Real Resistive, if it is R + N j it is complex Inductive if it is R - Nj it is complex...

How do I plot equivalent impedance v. frequency? I'm already in AC mode so the frequency is taken care of, but I keep trying to manually write trace expressions for zeq and nothing is working. any tips? EDIT: What does the trace expression IP(some element) mean? I think its related. EDIT2...

Hey, I'm finding equivalent impedances of circuits, and I always run into things like this: 1/(-j25) + 1/(600 +j900) = 1/Zeq I don't know how to proceed from here. I know this is more of a math issue than anything else, but I appreciate your help

I have to calculate the impedance (=R+j*w*L) of an infinite copper coil (par meter), with an iron core. Given data are the magnetic permeability, conductivity and radius of the copper wire, inside and outside radius of the coil, radius of the core and permeability and conductivity of the iron...

http://img420.imageshack.us/img420/9300/img02643tt.jpg hello this is the problem i am working on. i started out by using the admittance parameter equation i1 = y11*v1 + y12*v2 i2 = y21*v1 + y22*v2 so i1 is 20/50 by ohms law. so i1 = 0.4 so by the first equation i get v2 = 32 V. also...

The problem follows: Suppose you have a massless dashpot having two moving parts 1 and 2 that can move relative to one another along the x direction, which is transverse to the string direction z. Friction is provided by a fluid that retards the relative motion of the two moving parts. The...

Hi all, I'm currently studying up on transmission lines for my next midterm, and I stumble onto this problem. Given information: A 800 MHz transmission line that is lossless - Vmax, Vmin, V_L for a given load impedance R_L. - Characteristic impedance of a line - length of a line & \lambda...

Ok, need some help with the end part of this, here's the problem... The relation between the impedance Z and the refractive index n of a dielectric is given by Z=1/n. Light traveling in free space enters a glass lens which has a refractive index of 1.5 for free space wavelength of 5.5E-7 m...

Hi, I have some problems in understanding how to calculate the input (is it input?) impedance of a small circuit. (I have attached the equiv. circuit with values ) The circuit is a small loop antenna that resonates at 13.56 MHz and is tuned to 50 ohm. From the source point of view: a...

Hi, I have a HF transmitter rated with 200mW output power. An antenna is connected to the transmitter via a 50 ohm coax cable. (The antenna is also matched to 50 ohm.) Does this mean that from the transmitters point of veiw, a 50 ohm resistor is connected as load? Can I find the current...

Hello I am a newbie in all this stuff, so I would appreciate any help on this. I have come to posses an old amplifier, a Victor JA-S11 Stereo Integrated Amplifier, it is working very well and excellent sound quality. It has Headphone output jack. Currently I don't have any speakers to use...

Hi, I have a few 50 ohm loop antennas tuned to resonate at 13.56 MHz. (inductive RFID antenna). I would like to test one antenna´s influence on the other, so I think one approach is to connect one antenna directly to a signal generator. Do I have to design any matching circuit between the...

Can anyone figure out the input impedance of the circuit I have attached? Does anyone know a THOROUGH definition of input impedance? output impedance? Output impedance is equivalent to the thevenin impedance, which mean we turn off all voltage/current sources. But for input impedance...

OK, I think I am doing this question right, but I'm not exactly sure. The question is as follows: For an RLC circuit with a resistance of 16k\ohm , a capacitance of 8.0\mu F and an inductance of 38.0H what frequency is needed to minimize the impedance? Well impedance is give by: Z =...

if i want to connect a comparator chip's output (TTL) to Spartan2 FPGA board, can i directly do it, do i need to consider the impedance match? when i directly connect them, I will see the transition on the edge of the waveform stored (after FPGA processing, i save the output of FPGA and plot on...