A transmission is a machine in a power transmission system, which provides controlled application of power. Often the term 5-speed transmission refers simply to the gearbox, that uses gears and gear trains to provide speed and torque conversions from a rotating power source to another device.The term transmission properly refers to the whole drivetrain, including clutch, gearbox, prop shaft (for rear-wheel drive vehicles), differential, and final drive shafts. In America the term is sometimes used in casual speech to refer more specifically to the gearbox alone, and detailed usage differs.
The most common use is in motor vehicles, where the transmission adapts the output of the internal combustion engine to the drive wheels. Such engines need to operate at a relatively high rotational speed, which is inappropriate for starting, stopping, and slower travel. The transmission reduces the higher engine speed to the slower wheel speed, increasing torque in the process. Transmissions are also used on pedal bicycles, fixed machines, and where different rotational speeds and torques are adapted.
Often, a transmission has multiple gear ratios (or simply "gears") with the ability to switch between them as the speed varies. This switching may be done manually (by the operator) or automatically (by a control unit). Directional (forward and reverse) control may also be provided. Single-ratio transmissions also exist, which simply change the speed and torque (and sometimes direction) of motor output.
In motor vehicles, the transmission generally is connected to the engine crankshaft via a flywheel or clutch or fluid coupling, partly because internal combustion engines cannot run below a particular speed. The output of the transmission is transmitted via the driveshaft to one or more differentials, which drive the wheels. While a differential may also provide gear reduction, its primary purpose is to permit the wheels at either end of an axle to rotate at different speeds (essential to avoid wheel slippage on turns) as it changes the direction of rotation.
Conventional gear/belt transmissions are not the only mechanism for speed/torque adaptation. Alternative mechanisms include torque converters and power transformation (e.g. diesel-electric transmission and hydraulic drive system). Hybrid configurations also exist. Automatic transmissions use a valve body to shift gears using fluid pressures in response to engine RPM, speed, and throttle input.
I'm supposed to write a brief essay response to this question on my unit exam, and I don't exactly understand it. Please explain it to me, and then I can appropriately write the short essay. Thanks!
Homework Statement
"The energy companies use step-up transformers to send high voltage...
Homework Statement
A transmission line consists of a cylindrical conductor of radius r at a distance d in air from a conducting plane (r >>d).
Derive the capacitance per unit length C and the inductance per unit length L and
check that 1/sqrt(LC) = c.
Homework Equations
The...
Hi all,
The relation between the magnitudes of the incident, reflected and transmitted waves are obtained using Fresnel coefficients.
If a field moves from air to a more denser medium, which field should have a greater magnitude (reflected or transmitted)? I thought that it would be the...
My understanding is that the capacitance of a typical transmission line will increase proportionally to it's length. So in the case of a simple passive LPF circuit, consisting of just the LPF and the transmission line to the load (of infinite impedance), this would in turn mean the cut-off...
If you have a stick and push it from one end, the whole stick moves instantly. You have given the other end of the stick kinetic energy. So doesn't this mean that you have transmitted energy at an infinite rate, rather than at or below the speed of light?
Hi all,
I was reading "Geometrical Optics Reflected Fields" chapter from "Introduction to Uniform Geometrical Theory of Diffraction" textbook.
The author assumed that the surface is perfectly conducting and therefore he only considered the reflected waves. He derived a formula for the...
A transmission diffraction grating with
520 lines/mm is used to study the line spec-
trum of the light produced by a hydrogen
discharge tube. The grating is 1.6 m from the source (a hole
at the center of the meter stick). An observer
sees the first-order red line at a distance yred =...
Homework Statement
Create a boundary between two media by attaching a slinky to a coiled spring. Send pulses from one medium to the other.
Homework Equations
Describe what happens in both directions in term of speed, wavelength, frequency, and amplitude.
The Attempt at a Solution...
Hi all,
This is my first post, so please forgive me if this has already been discussed.
There is a question that has perplexed me for years, and I am hoping someone at this forum can shed light or point me in the right direction.
If two like charges separated by a distance, d, quickly and...
hiiii...
i needed some help in collecting some articles related to automatic transmission...i need the basic idea of it,and comparison with manual transmission...
Hi.
Do anybody here know how much and how quick a 50-100mm thick tempered glass plate of size 500mm * 500mm fully heated up within its bulk mass to a temperature of 60 degrees celcius looses it heat energy/temperature over time when surrounded by standing ambient air (20 degrees celcius)...
If a single conductor in a transmission line dissipates 6,000kWh of energy over a 24 hour period during which time the current in the conductor was 100 amps. What is the resistance in the conductor.
So could I just conver the kWh of energy to kW by dividing by 24 hours...than just use ohms...
Homework Statement
A river canyon is 147 m across as shown in Figure P.32. You are located on the river surface and clap your hands once to generate a brief acoustic pulse. You detect a time interval of 0.407 s between the twin echoes recorded on tape, analyzed when back home (?) in a...
I wonder what's the best efficiency that's possible to achieve with a continously variable transmission. I've googled a lot and can't find anything useful (with useful i mean an approximate value in [%]).
thanks.
If I was to measure the transmission of light through a coated piece of glass(with a coating designed to scatter light). Do I expect the optical transmission to be different if the light is incident upon the coated side compared to if the light is incident on the uncoated side and exits through...
The GPS (Global Positioning System) satellites are approximately 5.18 m across and transmit two low-power signals, one of which is at 1575.42 MHz (in the UHF band). In a series of laboratory tests on the satellite, you put two 1575.42 MHz UHF transmitters at opposite ends of the satellite. These...
Homework Statement
Design a dc transmission line that can transmit 225 MW of electricity 185 km with
only a 2.0% loss. The wires are to be made of aluminum and the voltage is 660 kV.
2. Homework Equations
P= IV = I^2 * R
R= p(L/A)
Power loss = Pf - Pi
Attempt at a solution
I worked through...
Hi,
Basically I'm doing a report on a logic analyser lab - I realize this isn't the homework section - and I'm looking to extend a basic discussion on synchronous/asynchronous data transmission to analysis of pumped and source-synchronous transmission...
I am studying EM wave and transmission lines. I see both derive equations for propagation constant \gamma:
Plane wave velocity is 1/\sqrt{\mu\epsilon} and \eta = \sqrt{\mu/\epsilon}
Transmission line velocity is 1/\sqrt{LC} and Z0=\sqrt{L/C}.
From that the book just to say the velocity...
Homework Statement
A beam of electrons of KE = 100 eV is incident from the left on a barrier
which is 200 eV high and 10 nm wide. If the momentum spread is sufficiently
narrow, then a simple plane wave is a good approximation. Recall that the mass of an
electron is mc2 = 511 keV.
....._____...
Homework Statement
A power station delivers 890 kW of power at 12 kV to a factory through wires with total resistance 5.0 \Omega.
How much less power is wasted if the electricity is delivered at 50 kV rather than 12 kV?
Homework Equations
eq-1) P = IV
eq-2) P = I2R
Ohm's Law...
Homework Statement
The aperture has vertical opaque strips of width, a, separated by open spaces of width 2a. The width of the overall aperture is L = 19a.
a) Write a transmission function for this aperture.
b) What would the field distribution be, at a plane in the Fraunhofer zone, if the...
Hello everybody,
I have a question and I am wondering if you can help me find an answer. The problem I am trying to figure out is:
I have 400 miles of 345 kV transmission line. An outage happened twice in two different locations on the line caused by two different lightning strikes, a 35kA...
Homework Statement
Why is serial data transmission preferred over parallel transmission when needing to transmit data over vast distances?
Homework Equations
The Attempt at a Solution
I think this has many different reasons...but I'm trying to pinpoint important ones.
-I think...
We are constantly told at school that in order to reduce power loss in overhead cables, high voltages and low currents are used as P = I squared R. This seems to make sense until you substitute I=V/R into P=VI and get P = V squared / R. Now if voltage is increased in the cable, and resistance...
Ok when they taught me about this they kept saying the power loss = I2*R
Well isn't the power loss also = V2 / R
Now before you give me the regular answer of "this V is not the same as this V", i understand. However, from what i know from the voltage divider rule is that the V across the...
I'm currently doing a lab on pulses in cables. The instructions describe the transmission line as a series of parallel lc circuits that transmit the pulse back and forth along the line, but I'm not sure I understand exactly how it works. I understand how an individual lc circuit works, but I'm...
I have been trying to interpretating the voltage and current phasors in transmission line. I want to verify with you guys/gals here what my understanding. I am using only the voltage phasor as an example. I separate phasor V(z) into V(z)+ and V(z)-. I put the load at z=0 and V(z=0) at +r axis(...
I am studying Poynting vectors. I run into question that I don't see any good explanation in all the books I have. All the books claimed
E_{(z,t)} =E_{(z=0)} Re[e_{j(wt-\beta z)} + \Gamma e_{j(wt+\beta z)}]
But sinse E0 is complex so this is what I have and is not equal to what the...
Hi
I am trying to calculate impedance in a line transmission but can't seem to figure it out :(
i have so far undertood that it is calculated by zo = R+jwL/G+jwC
The values i have found so far to help me with the task are:
R =100 ohms
L=225 micro henry
C = 9.3 Nano farads
G = 0.01 S...
Okay I'm just very confused by a statement in my textbook and could use some clarification. It says that power is transmitted at high voltages in order to minimize heat energy loss. It then says "it must be noted that this is because the higher the voltage is, the lower the current". Well...
I am considering the idea of making a small scale wind turbine for my final year B.Tech project. I have run into a roadblock, I have to maintain the generator at a relatively constant speed. I was thinking of 2 parallel shafts one from the Turbine blades coupled via a CVT to the shaft to the...
Problem :
a) A good sized English book has about 100000 words. If an average English word is six characters long and each character needs 1 byte, show that the book can be stored in 600 kbyte of memory and show that the text takes nearly 5 seconds to be transmitted at 1 Mbit s-¹. Show that it...
Light known to be polarized in the horizontal direction is incident on a polarizing sheet. It is observed that only 15 percent of the intensity of the incident light is transmitted through the sheet. What angle does the transmission axis of the sheet make with the horizontal?
I am not quite...
I think pretty much everybody knows the length of the transmission line should be less than the wave length of the RF signal.
How do you explain it to some one who is not from engineering background.
I myself can't get it some times.
Say for example the wavelength of a wave is
2" =...
Homework Statement
A source with 50 ohm source impedance drives a 50 ohm T-line that is 1/8 of a wavelength long, terminated in a load Z=50-j25 ohms. calculate TL, VSWR, and the input impedance seen by the source
I know you can name transitions between states like Lyman alpha, beta, gamma and whatnot but every time I see them they are written with a capital letter instead like K-alpha, beta, gamma.
I cannot actually find a table anywhere (yes I have googled) that sums up how the two naming...
Hi All,
we are planning to build a wireless audio transmitter. In 2.4GHz Band.
I would acknowledge that this is my first audio interfacing project.
So i have a lot of doubts about the way i can interface audio and stream the data out.
we plan to use an audio codec which can take Mic ( line...
Hello, I've been doing a bit of reading into Nicotine, but I am somewhat stuck. Any help would be much appreciated.
Nicotine binds with Cholinergic binding sites, or acetylcholine binding sites. My question is how do they differ? Why is Nicotine addictive, if without it you have Acetylcholine...
Hi all,
I have brave hopes of modeling the following problem:
Imagine an antenna transmitting an ~50V 100kHz sine wave. Imagine a receiving antenna placed three or four feet apart, with an amplification and detection circuit.
First, measure the amplitude of the received wave. Next...
Z in =50-j10 Ohms
i in=2 amps
length = 2 meters
Z0=75 Ohms
u=2E8 meters per second
beta=.3 rad/m
How do I find I+ and I- at the input?
What is the voltage at the load?
Any help would be appreciated.
Wireless Power transmission(URGENT)
Hi guys
Im actually plannin to build a wireless transmission system using induction, and without using a soft iron core. We are actually having 2 coils, one primary and one secondary. Our problem is that we aren't getting any kind of induction output. The...
Power station generates 120kW
Electricity can be transmitted either at 240V or at 24000V using a step-up transformer.
The cables have total resistance of 0.4W
What is the power loss when voltage is transmitted at:
1) 240V
2) 24000V
I AM SURE YOU CAN WORK THIS OUT USING I...
How is signal transmission speed determined in a transmission line? For example, what determines how long it takes a single pulse to go from one end of a line to the other end. I would assume it depends directly on the conductivity of the material from which the line is made but I'm not sure...
I know that smooth and cardiac muscle cells (myofibers) are connected to each other by gap junctions.
How are skeletal muscle cells connected to each other (to transmit the AP)?
Thanks, any responses appreciated
I have a question because of something I remembered while I was looking at some large copper windings for a generator.
I heard one of my teachers say that electricity moved along the surface of a copper wire. I am wondering how pitting a copper wire, making it sponge like, or carving...