A generator is a device that generates electricity from mechanical energy via different energy sources such as heat or kinetic energy of water.
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Can I pedal power a laptop device while the device is being used?
I want to research how easy it would be to use a small laptop device while powering it by pedaling on a stationary frame. (For example, using a tablet on an exercise bike, or using a netbook while ...
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8answers
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What's a good square wave generator?
What's a good circuit to use to generate a square wave? The exact waveform isn't too important - I just want to get a piezo buzzer cranking at 150 kHz. I also want efficiency and adjustable amplitude.
...
10
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2answers
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The electricity grid: what keeps small power generators from being 'driven' by large ones?
This is a two part question and pertains to power generation:
What prevents a larger plant (say nuclear) from turning an itsy-bitsy gas generator into an electric motor and drive current through it? ...
9
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2answers
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Is it possible to use Kinetic energy to power small devices?
I've tried looking around for as much information as I could gather to build really small wearable electronics that could power themselves by generating energy with movement.
I know that the ...
8
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1answer
482 views
What is 'load' in percentage?
Aircraft Airbus 320 has two 110/220v 400 hz 90 kva generators, run by two engines. There is an electronic display in the aircraft that also shows the parameters of the electrical system. One of the ...
8
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4answers
687 views
Is there a device that converts any AC frequency to 60 hz?
If I have something like a windmill generator that generates AC current, but at variable frequency, what device(s) would I need to convert that variable frequency into a constant 60hz frequency, so ...
7
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4answers
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What is back-emf: counter-electromotive force?
Could someone knowledgeable on the subject explain what exactly is this back emf?
How is it caused in a motor/generator, which components and which effects determines it?
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1answer
1k views
How does a gas grill starter spark work?
On some gas grills, there is a button you push which creates a spark to ignite the gas (propane, natural gas etc.)
My questions are probably pretty simple:
How does the button create the spark?
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3answers
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Putting far more mechanical energy into a generator than its electrical load
Funny how I was pondering about this question for a long part of the day yesterday, and today I was at stackoverflow and in the box with the featured questions from other SE sites this very related ...
6
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4answers
478 views
Hand Powered Generator
I'm interested in a hand powered generator similar to the one in this Gakken Helicopter Kit.
Are these easy to come by? Easy to make?
6
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3answers
378 views
Harvesting energy from a small amount of wind
I am currently investigating the feasibility of a project that would include the need of harvesting some energy from wind. The size constant of the generator and fans is about 2"x2"x2". The end goal ...
6
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4answers
273 views
Alternative Energy Storage
Can anyone suggest an alternative to energy from a battery?
I'd like a system to replace my deep cycle leisure battery, I currently use this 110 AH leisure battery with a 1200W inverter.
I run my ...
6
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2answers
288 views
Is electricity wasted when energy generated by power plant is not in immediate demand?
After my second series physics course I have begin to wonder how power plants control energy production to match the usage of a city.
There are several possible answers in my mind listed below:
...
6
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3answers
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Explanation for Differing Stator Winding Orientations
As a layperson, I'm trying to understand the basic configuration for an induction motor or generator. I've looked at many diagrams and photos/cutaways of stator wiring and I've noticed two different ...
6
votes
1answer
679 views
Compact Fluorescent Lamp Load Calculations
I help build/wire up large illuminated carnival/parade floats, and in the past we have used around 11,000 40w/60w GLS BC light bulbs in festoon sockets, powered by a 800KVA 3 phase diesel generator. ...
5
votes
4answers
303 views
How is electricity typically generated?
I am a pure physics guy, so I understand the fundamental processes behind the generation of electricity, but I'd like to know how to apply it. I was wondering what kind of methods were used in the ...
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3answers
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How to get half frequency square wave from sin wave?
The task is to get such wave:
I can get square wave from sin wave, but I have no idea how to make it half-frequency. Have some advices?
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votes
4answers
293 views
Will a faster rate of change of flux improve electricity generation?
From what I remember about electricity generation, a varying magnetic field is used, either the magnetic field or the coil moves to generate electricity.
e = dB/dT
where
e = voltage induced
B = ...
5
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2answers
378 views
How does a wind farm prevent the fastest spinning turbine from driving the slowest one?
Just what the title says.
On a wind farm spread across several score hectares, I assume, the wind-speed wouldn't be uniform. The faster spinning turbines would probably induce more electricity than ...
5
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2answers
359 views
How to generate 30Hz sine wave?
I'm building a voice ring modulator. Part of it involves a 30Hz carrier sine wave to modulate the voice with. Since I'm trying to build a portable device it will be DC powered, and since a function ...
5
votes
2answers
913 views
How do I modify a DC electric generator to get the same power at a lower speed?
This will be a theoretical question.
Suppose that I have a DC generator, and I'm getting 300VA power from it when it rotates at 2000rpm.
I want to make it run at a lower speed of about 700rpm, and I ...
5
votes
4answers
901 views
Blinking an LED using a generator as the source of electricity
I made a little windmill which is turning a small generator to light up an LED, but the voltage is too low even with high wind speed for the LED to glow. I thought maybe the electricity could be ...
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4answers
332 views
Generating electricity with wet newspapers?
For a project we're thinking of generating electricity out of wet newspapers. Is that possible? How much current would it generate?
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2answers
333 views
Will a 3 phase induction generator fight its own rotation?
So in a 3 phase induction generator with coils for the stator and magnets for on the rotor, I am wondering if the the current induced in the coils would create a magnetic field that would oppose the ...
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2answers
616 views
How to measure the “efficiency” of a generator?
I've built "linear generators" (a coil on a tube, with a free magnet inside), with different layouts and I want to measure which is one "is the best", or, at least, make some kind of profiling on ...
4
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1answer
179 views
Why not run high power truck-mounted electronics from the truck's engine?
At Burning Man, I see a lot of "art cars" based on internal combustion engine platforms using generators separate to the original vehicle's engine to power their LED displays and sound systems.
Why ...
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3answers
241 views
ways to generate (small amounts of) electricity
I'm searching into ways of generating very small amounts of electricity, by small I mean enough to light a couple of leds, nothing more
The main idea is to have toys that my daughters (2 and 4) can ...
4
votes
5answers
298 views
Is direct current really better for pumped-storage hydroelectricity facilities?
Currently the article equivalent to War of the Currents in Russian Wikipedia section says that direct current is beneficial to pumped-storage hydroelectricity plants and provides no reference to that ...
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1answer
376 views
How does a wind turbine protect the bank from a reversal in polarity when spin direction is reversed?
This is a follow-up question to an answer to How does a wind farm prevent the fastest spinning turbine from driving the slowest one?
Spinning a DC motor will generate electricity on it's terminals. ...
3
votes
5answers
407 views
Multiple crystals
I am building clock with ultimate precision.
There are few known ways to improve precision: temperature controlled environment and multiple crystals. I am implementing both.
I was going to use 5 ...
3
votes
2answers
417 views
why electric motor or alternator have stack of plates?
i have noticed that all of the transformer/motor/alternator/electric actuator have a stack of metal for stator ( or where winding is done. ). why is that needed ? can same thing not achieve by using a ...
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2answers
4k views
What is the difference between an alternator and a generator?
What is the difference between an alternator and a generator ?
3
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2answers
4k views
Can I Test Bug Zapper's Voltage With Multimeter?
I have The Executioner bug zapper:
Although it uses 2 AA 1.5v batteries, it also has voltage multiplier like Cockcroft–Walton generator i guess and would like to know if it is safe and would make ...
3
votes
1answer
216 views
Why would I get electrocuted if I touched a non-isolated power line with my feet on the ground?
AC is being produced at a power plant using, let's say, a giant dynamo. A coil is being rotated rapidly through a magnetic field thus generating AC current. This current is then regulated, transformed ...
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2answers
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Building an Ultrasound Generator
I need to generate ultrasound with a frequency of 1.5 MHz. The ultrasound should be pulsed as shown here
An ultrasound pulse should be 200 µs long, a pause (no ultrasound) is 800 µs long. The ...
3
votes
1answer
153 views
What makes automotive alternators so inneficient relative to other applications?
Automotive and some marine alternators typically have an efficiency curve with a peak of 60%.
Image from http://www.intechopen.com
Whereas alternators to other types of applications reach 96% of ...
3
votes
4answers
441 views
Sawtooth generator not working - transistor wont discharge my capacitor
I have been trying to build a sawtooth generator using current source which linearly charges my capacitor and a comparator which was supposed to discharge my capacitor, instead it doesn't. Here is the ...
3
votes
2answers
509 views
Which parts of this rotor can be made out of plastic?
I'm asked to redesign a rotor, by making as much parts of it as possible out of plastic. The issue is its weight, we want to make it as light as possible. Especially the shaft & axis of it is the ...
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1answer
139 views
Creating power from shaft rotation
I am a mechanical engineer and am working on a project. This project consists of a rotating shaft and I would like to generate power from that rotating shaft.The shaft will not be rotating ...
3
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4answers
221 views
For a vehicle, what is the most efficient way to store energy from various inputs?
Background
For the past few years I have wanted to make some sort of recreational vehicle that runs on multiple-source renewable energy. For example, a kayak with a trolling motor that gets its ...
3
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1answer
283 views
Simple generator to light a series of LEDs question
Playing around with a simple circuit idea with friends but none of us have really worked with circuits since college so we need a little guidance. The thought is to have a small generator (someone ...
3
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1answer
190 views
How should I make a generator-powered rectifier/regulator charge a battery?
In my bicycle, I have a hub generator which provides alternated current, at nominal 6V / 3W.
I have built a regulator/filter/rectifier, using a rectifier bridge, a 6800 uF electrolytic capacitor, and ...
3
votes
4answers
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What is the slip factor for an induction generator in an island network?
Most textbooks covering induction machines cover only the motor use-case scenario. When the machine is used as a motor, the slip factor is determined by the frequency of the stator current by the ...
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votes
5answers
471 views
why cannot generators having different frequencies supply in the same transmission line?
I am thinking of the issue that
the TEPCO electric transmission
networks cannot be taken over by other
electric companies because of
frequency difference.
TEPCO is the electric company ...
2
votes
5answers
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Hand crank DC generator - a simple dummy load that won't burn out?
I'm working on a project that allows a user to crank a hand generator while current and voltage sensors measure the output. After the user finishes cranking, software displays information about how ...
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3answers
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Could a significant amount of electricity be generated from public hand-operated generators?
So imagine you're at a bus stop at a train station. You're bored and have got nothing to do. So you see a big crank-handle sitting there doing nothing, and because you're bored, you decide to spin it ...
2
votes
4answers
238 views
Importance of keeping the electricity network frequency stable
The frequency in the electricity network is kept in balance by primary and secondary control among others (see e. g. here). I read that frequencies below 47.5 Hertz are dangerous and can lead to ...
2
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1answer
340 views
Alternation of Magnet Poles in DC and AC Generators
I want to create a generator. The current design I am looking at has several magnets along a wheel, with coils around the outside of the wheel. The wheel then spins generating current.
I know that if ...
2
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4answers
508 views
Alternator with torque proportional to angular velocity
Im interested in buying or designing an alternator/electrical generator that increases torque as rpms increase - is there an alternator design that increases resistance as rpm/angular velocity ...
2
votes
2answers
97 views
Using a motor as a generator: How fast does it need to rotate?
I have a dc motor with the following specifications:
...
