What is Power output: Definition and 138 Discussions
In radio transmission, transmitter power output (TPO) is the actual amount of power (in watts) of radio frequency (RF) energy that a transmitter produces at its output.
This is not the amount of power that a radio station reports as its power, as in "we're 100,000 watts of rock 'n' roll", which is usually the effective radiated power (ERP). The TPO for VHF-/UHF-transmitters is normally more than the ERP, for LF-/MF-transmitters it has nearly the same value, while for VLF-transmitters it may be less.
The radio antenna's design "focuses" the signal toward the horizon, creating gain and increasing the ERP. There is also some loss (negative gain) from the feedline, which reduces some of the TPO to the antenna by both resistance and by radiating a small part of the signal.
The basic equation relating transmitter to effective power is:
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{\displaystyle TPO\ \times \ loss_{feedline}\ \times \ gain_{antenna}\ =\ ERP}
Note that in this formula the Antenna Gain is expressed with reference to a tuned dipole (dBd)
First, I want to put forward an imaginary scenario where an ionized flow is being used to generate power/electricity by MHD power generation method. The temperature of the ionized flow is the same as the surrounding atmosphere. Power/electricity is generated as the flow is ionized. Now, if the...
I'm an engineering student and I recently watched a lecture from a wind farm control system engineer. He said that the national grid will call them up and ask for a specific amount of power. He then enters that value into the system and it will automatically adjust to achieve that power output...
Found this paper regarding performance of Tesla turbine. At the page 23, a formula regarding possible power output from a Tesla turbine is given. But, I want to know how to deduce the area given the formula. Tesla turbines are discs placed one after another with specific gaps in between the...
Hi,
I am confused about whether decreasing the magnetic field used for a generator could increase the generator's power output.
I used four equations:
1. Torque = Force x radius
2. Torque = NIAB (N = number of turns, I = current, A = area of armature, B = magnetic field).
3. emf =...
So...I have a home spin bike which unfortunately lacks the sensors of some of the more expensive models. What I'm trying to do is work out if I can dynamically calculate my power output.
The spin bike itself has:
- An 18kg flywheel of radius 30cm
- Direct drive between the crank and the...
I am ~180lbs and have been lifting weights for about 12 years straight. I have also been running 3-4 times per week for the last 8 ish years.
I have recently gotten into cycling, and noticed at the gym on the Schwinn "spin" bike, I will have peaks of around 400-500 watts, but it's definitely...
Basically this would be a closed loop geothermal system for electrical power generation. The system would consist of 2 Horizontal Wells connected creating a U-shaped closed loop cycle using thermosiphon effect, with constant recirculation. It's not really a conventional geothermal power...
I learned that solar panels have their maximal power output at a particular voltage and current level. If we want to get the max power, we have to connect a load with a specific resistance. However, in reality, how does the solar plants solve this problem? I guess they won't allow the power...
I have found the apparent weight of the man in the accelerating elevator
My question is about what speed I should use in the formula for the power output P = F ⋅ speed
My common sense tells me that the speed I should us is the speed v the man is climbing the ladder , because if the...
Although the universe is not old enough to experience these yet, but near the end of the lives of red dwarf stars, they will go from red to yellow, to blue eventually. Does this result in additional heat being given off of the surface of those stars? And if so, then does the habitable zone of...
Hello All,
Happy New Year!
A typical modern turbofan engine system creates lift as well as propulsion for the aircraft. Somewhere inside the system, the fast rotating device also works as a generator (alternator) to produce the electricity powering electrical/electronics equipments. What is the...
How did you find PF?: youtube
[Moderator: moved from new member intro forum]How did you find PF?: youtube
i need a falling mass over time /joules per kilo over 1hr time
also need to know how to figure gearing to maintain fall over time in regards to a set resistance such as a 5 kw alternator
To be more precise the generator has to be able to produce around 1.5 Watts from a person spinning its axis, which is why I was thinking of putting a gearbox in my design but I need to know how much Torque would it take to spin the axis and at what rpm would the generator be effective.
so, assuming that you know all of the aspects of your theoretical generator, apart from the voltage and current, how would you work it out. I know that it is possible, but i can't find anything that I understand, or is even valid online. There should be some equations i can use to work it all...
Homework Statement :
It takes gravity 1.43 seconds to pull a 3.67 kg cat down from a 10m tall ledge. What is the power output of gravity? [/B]
Homework Equations
P=mgd/t
P=w/t
P=power
M=mass
G=gravity
D=distance
W=work
T=time[/B]
The Attempt at a Solution
P=(3.67)(9.81)(10)/1.43
P=251.77
Homework Statement
Calculate average power output for a 75 kilogram person walking from ground level up stairs to a final height of 100 feet (then stops) in a time of 3 minutes
Homework Equations
P= work/ time or P=Fv
The Attempt at a Solution
I thought this was more of an energy problem...
Homework Statement
The power output of an automobile engine is directly proportional to the mass of air that can be forced into the volume of the engine’s cylinders to react chemically with gasoline. Many cars (like a 2008 Mini Cooper S) have a turbocharger, which compresses the air before it...
How can the slightly richer Air fuel ratio produce higher power while the temperature it produces is lesser than slightly leaner(slightly leaner than stoichiometric for best economy)?
FYI:I understood that ,at the stoichiometric ratio(precisely slightly leaner due to fast operation of engine)...
Homework Statement
Speech at a distance of 45.1 cm has a sound level of 59.3 dB. Assuming that the energy in the sound spreads out equally in all directions from the person's mouth, calculate the total power output from the person.
Given:
Distance= 0.451m
Sound level 59.3 dB
P=? J
Homework...
I recently re-read an article by Muller (https://arxiv.org/pdf/1606.07975.pdf) about the flow of time, and the possibility of time reversal given sufficient energy dissipation (basically during black hole evaporation, he concludes). Although the paper is on arXiv and not peer reviewed, Muller...
Homework Statement
A fire hose for use in urban areas must be able to shoot a stream of water to a maximum height of 34 m. The water leaves the hose at ground level in a circular stream 4.0 cm in diameter.
What minimum power is required to create such a stream of water? Every cubic meter of...
Hey folks,
I built a generator for fun and I would like to find out how much power it is producing when I use it. I have a way of measuring mechanical power in but I am not quite sure on how to measure electrical power out. I'm thinking I could use some LEDs to create a load (or maybe...
Homework Statement
Hello everyone, I'm working on a (simplified) Mars energy model in which I need to calculate the area of land I need to cover in solar panels in order to achieve an particular power output.
Say the land I'm looking at receives a constant solar irradiance of 100W/m^2 from...
I have a hydro turbine spinning at 62.746RPM and it produces 170.195Nm of torque.
It generates 1.1183kW but ideally, I would like to step it up to at least 4.5kW.
Is this possible using a gearbox and if so how can it be done?
I have a 2 AMP regulated DC power supply, with variable voltage 3 - 12 v. If in a small circuit, i.e, small copper wire with 1 ohm resistor. Why am i not getting at max Amps?
Homework Statement
A Verdant Power water turbine (a “windmill” in water) turns in the East River near New York City. Its propeller is 2.5 m in radius and spins at 32 rpm when in water that is moving at 2.0 m/s. The rotational inertia of the propeller is approximately 3.0 kg∙m^2. Determine...
Homework Statement
A 49.0 kg sprinter, starting from rest, runs 58.0 m in 9.90 s at constant acceleration.
What is the sprinter's power output at 1.90 s , 3.00 s , and 5.70 s ?
Homework Equations
##d=v_it + \frac{1}{2}at^2##
##F=ma##
##W=Fd##
##P=\frac{W}{t}##
The Attempt at a Solution
I got...
Hi guys, not sure if this is the right place. Its to do with an electronic project I've been working on. However please point me somewhere else if you know anywhere better suited! (It is quite a long post sorry)
Basically, I have created an LED array used for stimulating cells with light and I...
Hi,
I have a problem that I've been trying to figure out for a while but cannot seem to get on my own. I'm trying to figure out how much power will be generated in a motor given a certain amount of torque. The problem is, to find the amount of power output , I also need to know the rotational...
Homework Statement
Homework Equations
relevant equations listed with each question
The Attempt at a Solution
a)
to solve for the power output of the heater, i used the following equation: Power = Energy/time
i already know that Energy = Quantity
so based on this, i can solve for Q = mass(ice)...
Homework Statement
A solenoid contains 610 cycles, with a radius of 0.136m and a length of 0.87m. The current of the solenoid decreases linearly from the maximum value I0 to zero through the equation I(t)=I0−bt, where I0=0.31 A and b=0.21 A/s.
What is the power output of the electromagnetic...
Homework Statement
A system consists of a bicycle and a cyclist traveling at a constant velocity along a horizontal road.
The total resistive force acting on the system in 4.0N and its speed is 8.0 m/s. Calculate the useful power output of the cyclist.
The cyclist stops pedalling and the...
Hello,
Why do self regulating heating cables have such low power output per foot?
Power output in these cables does not exceed 20 W/ft at 10 degree C, and decreases as the temperature goes up.
Many of the cables I saw can withstand high temperatures (250 degree C power off and 150 degree C...
1. Homework Statement Homework Equations
P=dW/dt
The Attempt at a Solution
I feel like I did something incorrect because I didn't use the vertical distance at all. If I'm wrong, does it have something to do with the displacement?[/B]
Homework Statement
A pump draws 500 kg of water/min from a 12 m deep well. The water is ejected with a speed of 20 m/s.
a) What is the power output of the pump?
b) How high is the fountain (ignoring air resistance) Homework Equations
The Attempt at a Solution
For part a I found the potential...
Hello
Why does Mineral Insulated heating cables have such limited power output per feet and maximum operating voltages?
I thought it has to do with the dielectric strength of the MgO, that is used as an insulation in the coaxial cable, but the dielectric strength for MgO is higher than the...
I figure my 2.4 liter Volvo will burn about a liter of gasoline over an hour of idling (source: Natural Resources Canada). Since a liter of gasoline contains roughly 33.8 million joules (~9.4 kilowatt-hours) of energy, I figure that that means my car idles at a power output of around 9.4...
... it's amplitude exerts.
During cavitation a sound wave is applied to a liquid and breaks it apart and gas pockets are formed. The frequency and the amplitude of the sound wave effect the bubble/s.
My question is, if I have the power output of the device then how would this relate to the...
Homework Statement
a 0.25 kg piece of ice at -30°C is warmed by an electric heater and the following graph of temperature is produced.
-use the information on the graph to determine the power output of the heater
the graph shows that the ice went from -30degC to -10 degC in 150s
Homework...
I'm currently studying Mechanical Engineering at Level 3 in the UK and I'm beginning my integrated masters in September. I've missed a large chunk of my studies this year due to a broken collarbone I sustained earlier in the year. Instead of getting any special dispensation I'm trying to work my...
Homework Statement
During the power stroke in a four-stroke automobile engine, the piston is forced down as the mixture of combustion products and air undergoes an adiabatic expansion. Assume (1) the engine is running at 3400 cycles/min; (2) the gauge pressure immediately before the expansion...
Homework Statement
A speaker emits sound waves in all directions, and at a distance of 28 m from it the intensity level is 73 db. What is the total power put out by the speaker, in watts? ( reference intensity I_{0} is 1.0 × 10-12 W/m2.)
Homework Equations
P= I*A
I = I_{0}*10^{B/10}
SA =...
Hi guys
I have problem, basically I want to measure the power output from a water wheel.
so basically I measured the power output by connecting the pulley that attach on the shaft of the water wheel. then this pulley is connected to other pulley which sit on the shaft of the DC motor.
this DC...
Homework Statement
A ##\small{105\!-\!kg}## basketball player crouches down ##\small{0.400\ m}## while waiting to jump. After exerting a force on the floor through this ##\small{0.400\ m}##, his feet leave the floor and his center of gravity rises ##\small{0.950\ m}## above its normal standing...
Homework Statement
during a human heart beat, 20g of blood are pushed into the main arteries. This blood is accelerated from a speed of 0.20ms-1 to 0.34ms-1. For a heart pulsing at 70 beats per minute, calculate the average power of the heart pump.
Homework Equations
KE=1/2mv2
The Attempt at a...
I have a motore with a propeller anchored to a load cell to measure the lift produced at varying power inputs. This is for a student activity I am running and I wanted to show that though more power in gives more lift there is a point after which efficiencey starts to go down again so I tried to...
Homework Statement
In a hydroelectric plant, water falls from a high elevation to a lower elevation,losing PE in the process/ In doing so, it turns turbines which generate electricity. In a particular hydroelectric plant, water flows at a rate of 400 kg/s. If 80% of the PE that the water...
Homework Statement
Hi,
I am working on a temperature control system which involves using a power resistor to heat a block of aluminium and a thermocouple to measure the temperature. Both the thermocouple and the power resistor will be controlled using the NI USB-6008 and Labview.
As my...