Transmission Definition and 708 Threads

  1. A

    Solving Transmission Line Question: Find Phase Change Bₗ for l=0.4λ

    Homework Statement a transmission line has a length l of 0.4lambda. find the phase change Bl that occurs down the line. Homework Equations B x lambda= 2pi The Attempt at a Solution now here is my problem i am genuinely not sure where to go with this.i don't want this answered for...
  2. C

    Converting Transmission to Absorbance (Optics)

    I have taken data for the transmission vs. wavelength for several types of glasses in the IR. I want to convert this to absorbance so that I can generalize transmission to different thickness glasses. I found an equation online that stated A = 2-Log(T%) (where Log is base 10). But I do not...
  3. L

    Stadium Wave as Longitudinal Wave in Terms of Transmission

    So, the common high school physics example of a transverse wave is a "stadium wave" ... but, I'm wondering if this is actually longitudinal in terms of particle transmission. Each particle (audience member) is only standing up/down. The particles/audience stay in place and don't propagate/run...
  4. C

    Transmission coefficient (quantum tunnelling)

    Homework Statement What is transmission probability (T), when the incident particle energy (E) is equal to the energy of the barrier (U)? Homework Equations Equations to transmission and reflection probabilities. http://i950.photobucket.com/albums/ad348/gs5720/img099.png?t=1278212132...
  5. S

    2.45GHz RF microstrip Transmission Line design

    Hello all, I'm now working on the 2.45GHz frequency transmission line layout on the PCB. I would like to know whether there is a design guideline for the 1) minimum length of the transmission line. how do I know or calculate? I can calculate the width of the TL to get the 50ohm impedance...
  6. A

    Rectangular Pulse on a Transmission Line

    Homework Statement In Fig a line is used to produce a short rectangular pulse of width 12ns and peak value 800V. With S-2 open. S-1 is closed to charge the line to Vdc; after charging, S-1 is opened. Then, at t = 0, S-2 is closed to discharge the line through RR and form the pulse. Find the...
  7. L

    What Is the Best Wireless Communication Method for Long-Distance RC Vehicles?

    A friend and I are planning to build a remote controlled vehicle, probably 4 wheeled. We want to be able to operate over the distance of about a block, which isn't incredibly far. The tricky part is that we need it to be able to send us back audio and video, along with being able to receive...
  8. Math Is Hard

    Reverse gear on manual transmission cars

    When I was younger I drove stick shift cars. Reverse gear was always all the way over to the right and down in the cars I drove (MGB and Jetta). I'm car shopping now and thinking about getting a car with manual transmission again. I noticed that some have reverse gear down and right, but...
  9. T

    Why is AC Power Transmission More Efficient Than DC for Long Distances?

    Why is it that AC is superior to DC in long distance power transmisson. I was thinking it has something to do with the resistance of copper wire but if this is the reason then why is that? Or, why is copper loss not a factor with AC current? Thank you!
  10. M

    UV Spectroscopy - Absorbance vs transmission

    Hi In UV spectrscopy, is the definition of absorbance (A = ecl) derived from the definition of transmission (T = It/Io) where It is the transmitted light and Io is the incident light, or is the definition of transmission defined from absorbance. Also A = -log(T) and T = 10^-A = 10-ecl...
  11. S

    Tesla's claims for Wirless Power Transmission.

    How legit is the claim? I believe it as Tesla was unimaginably coolest inventor ever been on earth. Just imagine he is though to be responsible for 1908 Tunguska Event, though it is a rubbish theory but such a man, blamed for an explosion equal to the power 1000 times of the bomb that was...
  12. S

    Electronics required for transmission of signals in fibre

    HI ALL Well i want to know the power electronics required to transmit signals for sensors,limit switches ,push buttons up to PLC, and if analog device signals like potentiometer could be transmit tted with these ,how can i do this . i am using Plastic Optical Fibre and please help me with the...
  13. S

    Power Transmission: Questions about Power Generation Answered

    I had a question about power generation that was confusing me for awhile, I hope someone can clear it up. A specific amount of power is generated by the power plant. If I am not using all the power that I can use, where does it go? is all the power always in use? if it is not in...
  14. U

    Why has evolution failed to utilise radio transmission & reception?

    Evolution is the greatest nano-engineer that ever existed. I always assumed that if anything was physically possible at everyday Earth temperatures, forces and velocities then it would have emerged naturally from evolution, since the evolutionary benefits are clearly enormous. eg that's why...
  15. M

    Transmission of force(elasticity)

    Studying from Love's Treatise on elasticity I am having some difficulties. For an isotropic body under the influence of a force within a finite volume T equiations of equillibrium via Hooke's law are given by : (\lambda + \mu )(\frac{\partial}{\partial x},\frac{\partial}{\partial...
  16. A

    Standing Wave pattern on an open circuited transmission line with length λ/4

    Here's a scenario about which I have doubt. Consider a transmission line which has a length λ/4 and which has open circuit at load end. The source resistance is zero. The source voltage be Vs and the source frequency is sufficiently high to be considered as high frequency application . The line...
  17. Y

    Efficiency of Power Line Transmission

    Homework Statement Homework Equations N/A The Attempt at a Solution I have been struggling with these questions for the past week, with not much result at all. I have to study at home, through the use of various textbooks, and with no teacher to guide me through the process...
  18. H

    Transmission Electron Microscopy - Crystal Structure

    Hi I have a tutorial problem involving determining the ideal methods for identifying material properties of a layered semiconductor structure. The problem states to use either scanning or transmission electron microscopy. THe structure consists of several monolayers (around 5nm) of AlGaAs...
  19. M

    Calculating Self-Inductance and Capacitance in Parallel Plate Transmission Lines

    Two very large parallel conducting plates of very large length l, and width w are separated by a distance d. A current I=Jw flows to the right in the lower plate and to the left in the upper plate. Each of the two currents produces a magnetic field \frac{B}{2} between the two plates. (a)...
  20. B

    Calculating Power Transmission with Belt and Rope Drives: A Comprehensive Guide

    Two questions I am a bit stuck on, any kind of help would be appreciated :) 1 - In a belt drive the angle of lap on the small pulley is 150°. With a belt speed of 20m/s and a max tension of 1400N, the greatest power that can be transmitted is 10kW. What power could be transmitted for the same...
  21. Z

    Why AC instead of DC for Electric Power Transmission?

    Homework Statement Explain why A.C. is used instead of D.C. to transfer electrical power from the generating station to the consumer. Homework Equations The Attempt at a Solution To reduce the energy lost in long distance transmission. To reduce costs involved in transferring...
  22. 7

    Transmission of a TWO step potential

    Homework Statement Consider the potential: V(x) =0 x<0 =V1 0<x<a =V2 x>a Where 0<V1<V2 and E>V2 Evaluate the transmission coefficient for the incident wave into the region x>a Homework Equations T= 4k0k1/((k0+k1)^2) The Attempt at a Solution I have not attempted this. It...
  23. V

    Preventing Engine Overrun: Is Overdrive Transmission Relevant?

    How to prevent engine overrun? Is there any relation between overdrive transmission and engine overrunn? Pl. clarify?
  24. M

    PAM is not very good for long-distance transmission. Why is it so?

    Homework Statement Just came across the statement that PAM is not very good for long-distance transmission. Why is it so? Thanks. Homework EquationsThe Attempt at a Solution Is it because the output is of infinite length?
  25. S

    Transmission Coefficient of a Rectangular Square Potential Barrier

    If you have a rectangular square potential barrier of some height, say \lambda/L, and thickness L, what is the transmission coefficient and what is its value in the limit that L goes to 0? Thus you have the height of the barrier going to infinity, while the width goes to zero... Assuming...
  26. S

    Alternator on a long transmission line

    Could it be dangerous to connect an alternator to a long transmission line,if the line has high capacitance?if dangerous then why? please explain...
  27. A

    What Data Transmission Media should I choose?

    I need to connect 2 building. They're separated more than 30 KM. And they want to get a high transmission rate (between 2 Mbps until more than 155 Mbps). The transmission must not get disturbed by electromagnetic wave at all. The budget is not a problem. What media should I choose? And why...
  28. F

    How system frequency is controlled on the electricity transmission system

    Hi can anyone direct me to some good information on how system frequency is controlled on the electricity transmission system?
  29. T

    US grid power transmission via plasma

    I'm doing some classic research into the possibility of replacing copper core power transmission lines in the United States power grid with tubes designed to contain low temperature plasma. The idea is that one would be able to transmit power more efficiently and effectively in plasma opposed...
  30. S

    Current Transmission in power lines

    If the electric field at a point drops off in intensity as the inverse ratio of the square of distance from the source, how do power lines manage to carry current through such large distances?
  31. T

    High power, short distance electrical transmission problem

    I’m in a situation where I need to power 150 machines, each one consuming 2kW of power. The trick is that it rolls on a metal track at high velocities. I am concerned about transmission loss and type of contact. I could power the machine with a physical contact via carbon bushings to a...
  32. R

    Transient (Time domain) in transmission lines

    Hello. I am watching this video: https://www.youtube.com/watch?v=xIQtnQ9XPbE and he says there: I see that the wave turns into a "normal" sinus in the end, but it's not constant. I think, that even on an unmatched transmission line, the waves should go back and forth, but eventually...
  33. A

    Sound Transmission: Glass vs. Wood Doors

    Homework Statement when people speak inside a closed cabin with glass doors, sound is not heard outside where as with wooden doors it is heard outside. What is the correct explanation? Is it because, sound is not at all transmitted through glass, or, absorbed by the glass? What is the exact...
  34. R

    Gears in Transmission: How to Improve Performance

    Hi PFians and friends Have a look at this basic transmission. I was wondering if the gears on the layshaft somehow remain of same radius as the first gear on layshaft (I know then the mechanism has to be different), then won't be our transmission better. e.g consider the case of 1...
  35. Y

    Calculating Transmission of Electromagnetic Wave in COMSOL

    Hello All, I have a fundamental Comsol question that maybe you can help me with. If I am in say a 2-D In-Plane TE Mode. I am inputting a wave that will propagate left to right. What is the best way solve for the resulting field that is transmitted to the right boundary, regardless of what...
  36. C

    Using transmission lines to lift trains

    well, if we lay power lines along rails and use the magnetic field to lift trains, would it increase the transmission loss?
  37. W

    Lossless transmission line and a lossless antenna

    Hi All, I understand that if you have a lossless transmission line and a lossless antenna and there is a mismatch at the antenna/transmission line junction, no energy is lost. If the transmitter is delivering 100 watts into the line, 100 watts will be radiated from the antenna. I'm...
  38. D

    Transmission Bandwith though space

    I have a very little understanding of astrophysics. I wanted to know what kind of transmission bandwidth can travel through space without dissipating.
  39. T

    Transmission line relative amplitude question

    Homework Statement An annular sheet (i.e. a flattened ring) , of thickness t = 1mm and made of a material of resistivity 0.5 Ohm m connects the inner and outer conductors of an air spaced coaxial transmission line at a point on the line. A low frequency signal is fed into one end of the line...
  40. I_am_learning

    Is Wireless Power Transmission Viable for Offshore Technologies Today?

    How much practical is wireless power transmission, in the light of present days technologies?? Are Laser based systems more efficient than Induction Based systems?? How good are microwave based system??
  41. C

    Is There a Formula for Maximum Mechanical Power Transmission at 90 Degrees?

    Hi all Serching along this PF I found this formula to solve the power transmission between piston and crankshaft. I have then drawn this to show it. According to this formula we have a maximum (100%) power transmission when angle theta is 90º. I think we should have some power loss even at...
  42. S

    Transmission Line, voltage drop

    Homework Statement Prove that for a line having resistance R, and reactance X, and supplying load of P+jQ has an approximate voltage drop of: Vr = [RP+XQ]/Vs Homework Equations none given. The Attempt at a Solution I made a diagram, with R, X, and P+jQ in series. Vr is the...
  43. L

    VSWR and transmission lines help

    I had set up an inductive and capacitative ladder network to model a coaxial cable( or low pass filter)- 20 sections of L= 0.1 H and C=0.11 microF That works out as a characteristic impedance of 953ohms. The circuit starts at a signal generator, then 5ohms resistor before the low pass...
  44. L

    Understanding Voltage Discrepancies in Transmission Lines: A Brief Overview

    I was reading about transmission lines. I thought if the line and load are matched, then the voltage on the line will be equal to the voltage on the load. But fig 16.2 (page 1000) in the book here, the voltage at load is half the line voltage. I don't get it! Book link- (click the contents link...
  45. S

    What makes current flow in a transmission line?

    In a transmission line, what makes the current flow? I understand that the line is excited by an AC voltage at one end. This sets up a changing electric field between the conductors and therefore a changing magnetic field. However, there is no voltage along the line, so what makes the current...
  46. C

    What is the Explanation for the DOS of Metallic CNT?

    DOS of metallic CNT Hi all, I am in doubt on a subject. The density of states function of a metallic CNT, is given as http://img196.imageshack.us/img196/5629/adszuci.jpg in the book "Introduction to Nanoelectronics" of Hanson. On the other hand, in the same book, it is said that...
  47. T

    Transmission Coefficient for two step potential

    Homework Statement E>V_1 & V_2 So it's a step potential wave, setup. Let's set it up along the x axis. At x=0, there is the first step where it is V_1. At x=a, there is another step, where V_2>V_1. Show that the transmission coefficient is...
  48. L

    Transmission line approimation

    Transmission line approximation Homework Statement In the derivation of the approximate formulas of \gamma and Z0 for low loss lines, all terms containing the second and higher order powers of R/wL and G/wC were neglected in comparison with unity. (R/wL<<1 and G/wC<<1)...
  49. J

    HIV Transmission: Can a Child Get AIDS?

    here is a question suppose a sperm and a ova fuse with each other none of these are infected with AIDS the zygote is formed now this is transplanted into the uterus of a mother infected with AIDS will the child also have AIDS?
  50. W

    How to Integrate a Counter in a Data Transmission Circuit?

    Hi! I want to design a data transmission circuit (transmit 7 bits data with 1 start, stop, and parity bit) by using gates. The part I have done is CRC and parity.Now I want to design the transmission part, I want to use a counter to count the time of data division until 8 then transmit the...
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