# What is Power transfer: Definition and 76 Discussions

Energy transformation, also known as energy conversion, is the process of changing energy from one form to another. In physics, energy is a quantity that provides the capacity to perform work (e.g. Lifting an object) or provides heat. In addition to being converted, according to the law of conservation of energy, energy is transferable to a different location or object, but it cannot be created or destroyed.
The energy in many of its forms may be used in natural processes, or to provide some service to society such as heating, refrigeration, lighting or performing mechanical work to operate machines. For example, to heat a home, the furnace burns fuel, whose chemical potential energy is converted into thermal energy, which is then transferred to the home's air to raise its temperature.

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1. ### Determine the overall efficiency of a 4 into one gearbox configuration

So I'm trying to figure out the overall efficiency of this particular gear system. I have four gearboxes, each stationary in and of themselves, all driving a central ring gear which is permanently attached to a rotating shaft. Please see the attached sketch. If each one of the perimeter...

3. ### Questions About Highly Coupled Magnetic Resonance

This is one of very few in-depth sources of information I can find online about Highly Coupled Magnetic Resonance...
4. ### Wireless Power Transfer (is this correct)

Ref: https://www.semanticscholar.org/paper/Design-and-Simulation-of-Different-Wireless-Power-Baroi-Isla m/dc19ecfde904964704777ab5adef96d5d6846f1f I couldn't find the working of this circuit so I guess it would be like: Initially transistor is OFF, so the current flows through Base, and...
5. ### Engineering Homework: Rx=? to get maximum power transfer at point M

Hi, after calculations I end up in the circuit below¨ (Thevenin equivalent) So now I have to say Rth=RL and I will find Rx ?The initial circuit is this: Thanks
6. ### Electrical Network Problem: Power Transfer

Homework Statement Homework Equations P=V2/R For maximum power transfer, Rload=RThevenin The Attempt at a Solution I know the efficiency is 50% during maximum power transfer. So when all the sources are acting simultaneously and ( at the same time) R=Rth, maximum power will be dissipated in...

Hi all, I am currently working on a project where the output/load consists of both a variable inductance and variable resistance, whilst the circuit driving this load is a class E radio frequency (RF) power amplifier with low resistance but relatively high/medium reactance (attempting to design...
8. ### Difference in power transfer with gear location

I'd like to know if there's a power transfer loss depending on how gears are connected and placed relative to each other. For the two distinct image down below, imagine ALL GEARS HAVE EXACTLY THE SAME DIAMETERS and the setup is such that the viewers are seeing the top (aerial view) and the gears...
9. ### Electrical DIY wireless power transfer device concept

i am planning to do a small diy wireless power transfer device. The circuit of the transmitter is receiver has just the coil and load arrangement. my query is, (please correct me if am wrong) -->to induce a voltage in the secondary coil, there must be a varying magnetic field right? -->but...
10. ### Maximum Power Transfer Ideal Transformer

Homework Statement Given the following circuit find the value of ZL for maximum average power transfer and find the maximum power. Homework Equations n = N2/N1 V2/V1 = N2/N1 I2/I1= N1/N2 The Attempt at a Solution move ZL from the secondary coil to the primary coil using Zs* = ZL/n^2 ZL =...
11. ### Using the maximum power transfer theorem

Homework Statement Using the maximum power transfer theorem, find the value of R which will result in the maximum power being delivered to R. Homework Equations P_max= (V_oc)^2/4(R_th)) R_L=R_th P_RL=(V_th/(R_th+R_L))^2*R_L The Attempt at a Solution I have no clue where to even begin with...
12. ### Wireless power transfer topics

Hello , I am doing my M.Sc in wireless power transfer using resonant inductive coupling.I want to know what topics i should read and understand to master this research.
13. ### Electromagnetiic wave power transfer

Is the power in an electromagnetic wave equally transferred along both the electric and magnetic fields?
14. ### Max Power Transfer Homework: Find Ro for Max Power

Homework Statement Hey guys, I have been struggling on this problem for a while now and was hoping I could get a little help What is wanted is the maximum value of Ro for maximum power. Homework EquationsThe Attempt at a Solution Knowing that the Maximum power transfer to Ro would be when...
15. ### Maxwel 3D Wireless Power Transfer setup simulation errors

Dear All, i am new to Maxwell 3D software. i want to simulate my Wireless Power transmission Project in Maxwell, for this purpose i took help from different toturials whic abled me to draw the Tx and RX coils...i want to simulate these coils to calculate the values of L, M, K and etc. but i am...
16. ### Modeling a Black Box Circuit for Maximum Power Transfer

Homework Statement The question is showed as below. Homework Equations I don't know how to find i when the resistor is 4 ohm. I think it is quite difficult as the voltage is varying all the time. So how do I find the current? Thanks! The Attempt at a Solution
17. ### Where does the other 50% of energy go in wireless power transfer?

Hello, I am a student doing a research at university.I am working on wireless electricity transfer.I have two coils forming transmitter and Receiver. My coils are with diameter 17 cm. I have reached 53% efficiency in 15cm.And It is not increasing anyhow whatever I do. I want to ask where other...
18. ### Wireless Power Transfer: Magnetic Flux?

If a conductor carrying current has magnetic flux around it,why not a carrier wave that carries current in case of wireless power transfer has a magnetic flux around it?
19. ### Max Power Transfer: Optimal Load for Piezo & EM Gen

Hello everyone, I have two generators, piezoelectric and electromagnetic generator. Piezoelectrics are producing maximum voltage across 3 Mohm resistor where as EM generator is producing maximum voltage at 68 ohm. What would be the ideal load for to get the maximum output from both when...
20. ### High Efficient wireless power transfer

I have been working on the wireless energy transfer recently.Therefore, I am having low efficiency.I have set several coils with different parameters.Could anybody suggest any method to increase the efficiency?I want to transmit high voltage with high efficiency about 50-70W. I have tried with...
21. ### Max Power Transfer to Ro: Percentage Explained

Homework Statement The variable resistor R in the ciruit is adjusted for maximum power to Ro. what percentage of total power developed in circuit is transferred to R. Homework Equations i=V/R The Attempt at a Solution So my goal is to put a "fake" charge across v/2(the dependent source) of 1A...
22. ### Inductive transfer via mag. fields, max power transfer?

Hey guys; I'm looking for info on the maximum power transfer using the magnetic induction method. The current through a coil, then catch the mag field with another coil idea. Mainly looking for high energy transfer methods, maybe some equations that describe it. A friend and i are playing...
23. ### Find the resistance for maximum power transfer

Homework Statement Find the value of R where RL equals 50 Ω, for maximum power transfer I= 2A, R_L=50 ohms Homework Equations R_th=V_oc/I_sc KCL,KVL,V=IR The Attempt at a Solution First, I created an open circuit including everything except R_L. Then i tried to solve for the Open Circuit...
24. ### What is the Maximum Power Transfer Theorem?

1. Homework Statement A voltage source of 240 v having an internal impedance of (3-j4) ohm, is supplying power to a complex load impedance Z1. What will be the maximum power transferred to load? 2. Homework Equations 3. The Attempt at a Solution
25. ### Engineering Thevenin equivalent of circuit and maximum power transfer

Homework Statement Find the Thévenin equivalent of the circuit and the required value of the load for maximum power transfer for Z = 15 + j24 Ω . Homework Equations Voltage divider equation and Z_{in} = Z_{load} 'complex conjugate' for maximum power transfer. The Attempt at a...
26. ### Engineering Maximum power transfer in circuit

Just wanted to see if I did this right
27. ### Comparing Belt & Gear Systems for Power Transfer

What are the factors to take into account when deciding between using a belt or a gear system for transferring power? Thanks
28. ### Maximum Power Transfer problem

Homework Statement For the following circuit, find the values of RL and CL that maximize the power extracted from the generator. https://dl.dropboxusercontent.com/u/15390227/circuit.jpg Homework Equations Z = R + jX XL = jωL XC = 1/jωC The Attempt at a Solution Immediately...
29. ### Radio waves emitted by an inductively coupled power transfer system

I would like to know if a a inductively coupled power transfer system also emits electromagnetiv waves. The system contains of two inductance coils one generating the magnetic field with AC, the other picking up the magnetic energy and transforms it into an AC, also. The current frequency is...
30. ### Norton theorem,max. power transfer

Homework Statement How should I calculate the max. power transfer to Xload? The (20+30j) of Xload,it is not necessary. Homework Equations I try to find the answer,but I got two answers by different method. The Attempt at a Solution
31. ### Transmission Line, Max Real Power Transfer

Homework Statement A 230kV, 160km long transmission line has the following parameters expressed on a 230kV, 100MVA base. R = 0.0151 X = 0.1476 Y = 0.288 The sending end voltage of the line is held constant at 1.0 pu. The load at the receiving end has a lagging power factor of 0.8...
32. ### Power transfer with movable wiper

Homework Statement In the circuit shown below, a potentiometer is connected across the load resistor RL. The total resistance of the potentiometer is R = R1+R2 = 5 kΩ. (a) Obtain an expression for the power PL dissipated in RL for any value of R1. (b) Plot PL versus R1 over the full range...
33. ### Engineering Maximum power transfer in a circuit

Homework Statement a) What value of the load resistor RL will extract the maximum amount of power from the circuit below? b) How much power will that be? Hint: you need to use both the concepts of Thevenin equivalent circuits and maximum power transfer. Homework Equations The...
34. ### Max Power Transfer: Source Voltage & Load Explained

Hello, I was wondering, why is it that when calculating the maximum power transfer, the source voltage is the thévenin voltage, and not the actual source? What we call the load is arbitrary, no?
35. ### Inductive Power Transfer across a metal

Hi folks, This is probably a fairly basic question with a fairly easy answer. I was wondering if you could use the concept of inductive power transfer using a copper coil on each side of a metal barrier? If that metal barrier was a non-magnetic alloy. I have attached 2 drawings showing 3...
36. ### Maximum Power Transfer for Z = 12+24 Ohms

Homework Statement Find the required value of the load to achieve maximum power transfer for Z = 12+24 ohms Homework Equations ZL = Zs [b]3. The Attempt at a Solution [/b As the question does not state whether or not the phase or magnitude of the load can or cannot be varied. I...
37. ### Maximize Average Power Transfer with Impedance ZL - Circuit Analysis Homework

Homework Statement a) For the circuit shown, determine the impedance ZL that results in maximum average power transfer to the ZL b) What is the maximum average power transferred to the load impedance?Homework EquationsThevenin, Norton procedures, voltage division, current division, etc etcMax...
38. ### Maximum Power Transfer for Coupled Emitter Follower

Homework Statement For the attached emitter follower circuit, calculate the maximum ac power (Sinusoidal signal) delivered to an attached load. I have already calculated Rout of the circuit as 19.2Ω, and the voltage at the emitter at operating point (no input signal) as 10.7V (I know...
39. ### Maximum power transfer and kirchoffs

Hi Folks I need a bit of help, My weakness is kirchhoffs law and algebra, I know but I still give it a try. For this task I am required to calculate the value of the load (RL) using kirchhoffs and then I have to find the maximum power transfer for the circuit. I have attempted to calculate the...
40. ### Archived How Does Shaft Diameter Affect Power Transmission and Torque?

A shaft runs at 300 rev/min and transmits power from a pulley A at one end to two pulleys, B and C, which each drive a machine in a workshop. The distance between pulleys A and B is 3 m and that between B and C is 2.4 m (i.e. the total length of the shaft is 5.4 m). The shaft has a diameter...
41. ### What exactly are they asking in this question? Optimum power transfer

Homework Statement What is the range of values for [RL/RTH] that provide a combination of “almost” optimum power transfer to the load at a reasonably high power-transfer efficiency? Homework Equations The Attempt at a Solution What are they asking for in this question? What do they mean by...
42. ### I'm investigating maximum power transfer in a AC circuit

Hi, I'm investigating maximum power transfer in a AC circuit. I understand that for maximum power transfer the reactance both cancel each other out and the value of the source resistance and load resistance have to be equal. I have also found some formulas to prove this. what i would like...
43. ### Maximum Power Transfer with Negative Thevenin Resistance?

Hello everyone! I have a general question about how to find out the maximum power transfer to a load resistor with a negative Thevenin Resistance (Rth < 0). I know for positive cases, P = R*(Vth/(R + Rth))^2, in which R is the load resistor connected to the Thevenin equivalence circuit, and Pmax...
44. ### Maximum Power Transfer Theorem

Homework Statement "If the load voltage at the output of a circuit keeps going up as the load resistance is increased, why doesn’t the load power keep going up as well?" Homework Equations The maximum power transfer theorem states: A load will receive maximum power from a network...
45. ### How does wireless power transfer produce magnetic flux?

From what I learned, for an electric current to be induced in a wire, there must be a magnetic flux. On youtube, there are lots of videos showing wireless power transfer to a lightbulb or LED. However, the light is constant. How is the magnetic flux changing in such a setup?
46. ### Help with this problem - finding power transfer to R load

help with this problem -- finding power transfer to R load :) http://img99.imageshack.us/img99/610/08072012060.jpg i want help with finding Vth and finding power transfer to R load thanks all
47. ### Mechanical Power Transfer, trying to figure out the wiggle factor?

Mechanical Power Transfer, trying to figure out the wiggle factor? I’m trying to figure out “power transfer” using drive belts, probably serpentine, possibly cogged. If you have a primary drive belt that comes forward from say a 25Hp motor to power a secondary serpentine belt. The thing I...
48. ### Wireless Power Transfer via Strongly Coupled Magnetic Resonances

Hi eveyone. I really need your help for this project that I will be undertaking soon. But there is much I still don't understand and my lecturers aren't around to help. The setup that I'm envisioning is like this-- Source(230V 50hz) connects to signal generator, signal generator to 1st RLC...
49. ### Maximum power transfer theorem leading to erroneous result Why?

Hi everybody, Below is a circuit that I am investigating. All the components are linear, nothing fancy here. My goal is to maximize the average power P dissipated in the resistor Re. To this aim, I am only allowed to play with the angular frequency ω of the voltage source and with the value...
50. ### Engineering Designing a matching circuit for maximum power transfer

Hello. I need to design a matching circuit to provide maximum power transfer from a generator with impedance Zg to a load with impedance ZL. The matching circuit has a length of transmission line with impedance Z0 and short circuit or open circuit stub with impedance Zs. I need to design with...