Generator Definition and 1000 Threads

In electricity generation, a generator is a device that converts motive power (mechanical energy) into electrical power for use in an external circuit. Sources of mechanical energy include steam turbines, gas turbines, water turbines, internal combustion engines, wind turbines and even hand cranks. The first electromagnetic generator, the Faraday disk, was invented in 1831 by British scientist Michael Faraday. Generators provide nearly all of the power for electric power grids.
The reverse conversion of electrical energy into mechanical energy is done by an electric motor, and motors and generators have many similarities. Many motors can be mechanically driven to generate electricity; frequently they make acceptable manual generators.

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  1. W

    Serl Effect Generator: What Is It?

    What is Serl effect generator ?
  2. M

    Mechanically driven generator & inductive resistance to torque

    I have found research from multiple sources and probably shouldn't question but I want to be clear. Inside a generator you have a fixed number of poles and a fixed number of induction coils, the particulars are not important. As a pole rotates past the "inductor" which holds the coil there...
  3. F

    Induced voltage in a coil in a three phase permanent magnet axial flux generator

    I am currently designing a three phase permanent magnet axial flux generator, but have a question regarding the voltage induced in the copper coils. Faraday's law defines this voltage as the number of turns in the coil, times the change in flux (external magnetic field times area of coil) over...
  4. S

    Lightbulb and mini hydro generator

    I am using a 1.5 V incandescent light bulb. I know that if I connect a 9V battery to it or any higher voltage, it will burn it due to the large current flowing through it (Ohm's law if V goes up then the current goes up as well assuming constant R). Now I a have a 12 V mini hydro generator...
  5. T

    Lagging or leading synchronous generator

    Hi, It has been a long time since I studied synchronous machines and I am trying to understand the mechanism of how the armature excitation can result in the generator being lagging or leading. So please correct me if I say something like it's axiomatic but its really erroneous. Now, according...
  6. R

    Synchronous Generator Short Circuit - Hazards

    What are the possible hazards and causes of short circuit internally in a synchronous generator?
  7. J

    External characteristics of a DC generator are.... (multiple choice)

    Homework Statement Homework Equations The Attempt at a Solution I think External char = Magnaetic characteristics - Armature reaction drop - Ohmic drop since we're subtracting these values from voltage. But book answer is D. Magnetization char + armature reaction - Ohmic drop. Is book...
  8. J

    Residual magnetism in shunt generator reverse F1F2

    Hi, I'm not able to understand how reversing Field terminals will help build magnetic flux in dc shunt generator Have drawn diagrams below. In 1st case machine doesn't generate as the flux opposes residual flux, so I reverse F1, F2 and draw below diagram... But in second case the direction of...
  9. M

    Exploring Marx Generator Physics: Seeking Answers

    https://en.m.wikipedia.org/wiki/Marx_generator I chose the prefix to get an educated answer. I am not school educated but rather self taught, also instead of focusing primarily on electronics I have studied for the past several years the broader spectrum of electromagnetic phenomena including...
  10. D

    Two AC Sources with One Transformer

    I want to program a little power grid game and have the problem of connecting things via transformers. Imagine the following setup: You can see the AC voltage sources as generators (or together with the resistor as a "consumer", if the amplitude is 0). What I need to figure out are the...
  11. A

    Choosing a wind turbine generator

    I'm doing a school project in which I'm building a wind turbine. The next step for me is to choose a generator but I'm not completely sure what is right for me. I expect to come up to 300 rpm as an average and need the required voltage to for a car battery, which is around 14.4 volt. My...
  12. G

    Need help with a thought experiment about a Faraday generator

    Hi, I arrived at a paradox today which I cannot explain myself. I was watching some physics videos on youtube and among them some were about lenz law and faraday disc workings. Now I know and understand the classical examples of why there is current generated when the magnet moves together with...
  13. Cocoleia

    Why does a larger synchronous generator have a better rating

    Homework Statement I read in my notes that "The physical size of a synchronous generator of a particular rating is larger than one of a lower rating" Why is this so ? The Attempt at a Solution Is it because a larger one would be able to supply more power and therefore the rating would be higher ?
  14. Steven Robinson

    How to calculate max current potential in a windmill generator....

    Hi, new member with a question that I might be asking wrong. A week ago I read an article or something on building a windmill generator, which I come back to every few years. So, this week, I was reading about how to calculate the voltage based on loops, turns, Teslas, area, RPMs and such, and I...
  15. G

    Generator size vs frequency question

    Hi folks , a simple question, is it true that generators are like transformers in regard to the frequency of the AC being generated versus the size of the device for given amount of power transfer? We know that transformers can have smaller cores with fewer turns if the frequency of the AC is...
  16. S

    Understanding the Winding and Voltages of an AC Generator: A Hyundai Unit

    Hi. Can anyone tell me how my AC generator is constructed. It is a Hyundai unit, the main windings consist of 4 wires in parallel, 2 sets of 6 coils, each one of the set is maybe 8 or 10 turns. There is a secondary pair of 2 windings each. This is centre-tapped, so I guess to provide exciter...
  17. vanhees71

    The Homopolar Generator: An Analytical Example - Comments

    Greg Bernhardt submitted a new PF Insights post The Homopolar Generator: An Analytical Example Continue reading the Original PF Insights Post.
  18. D

    What generator/DC motor do I need for my wind turbine

    I am making a small wind turbine for my A-level RMT and wondering what kind of generator I need to charge a 12volt battery. The turbine is a vertical axis savonius turbine that will probably be about a meter high and half a meter wide. I know I can use permanent magnet dc motors and someone...
  19. G

    Testing a Microcontroller with a Function Generator

    Hello, I have more of a mechanical background so I was looking to get some help from someone with an electrical background with this. I am trying to use a BK Precision Function Generator (datasheet: https://bkpmedia.s3.amazonaws.com/downloads/manuals/en-us/4017A_manual.pdf) to send a signal to...
  20. javi2018

    Can R4 be replaced with a jumper in an ultrasonic generator circuit?

    I let you a circuit that is an ultrasonic generator to 500 khz, you feel free to include some improvement.
  21. D

    BLDC motor as generator to power eddy current brakes

    Hi everyone - here's a concept that I'd like a few opinions on: As part of a project, I'm looking at using a brushless DC motor mounted on a high-speed vehicle as a generator. Once the vehicle hits its top speed, the batteries should disconnect from the motor and the vehicle's own velocity will...
  22. E

    Synchronous generator reactance (Sub, transient, SS)

    Hi I know that when studying fault conditions for synchronous machines you have three reactances: Sub, transient and steady state reactance. Where the magnitude of the reactances are (from smallest to largest) in the same order as previously listed. However, I have tried searching - hoping to...
  23. S

    Saltwater Generator: Harnessing Electricity from Salt Water

    I know very little about engineering and I would like to know if its possible to create a generator that uses salt water similarly to a salt water battery and generates electricity by simply being placed in salt water.
  24. H

    Is LNG a Better Alternative to Diesel for Generators?

    Hi all, This is related to this thread https://www.physicsforums.com/threads/solar-batteries.928495/ I just heard that in 2 - 3 years, the LNG mains will be installed in my area. I need some help to gather info on modern LNG generator performance (the latest models, just in case the older...
  25. T

    Measuring the Power Output of a Generator

    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...
  26. M

    Portable Energy Generator for off-Grid Villages

    I am a 3rd year integrated Engineering Student. For our 3rd year project we decided to make a portable generator to power laptops that were previously donated to an isolated off grid village in Nepal (for educational purposes). The laptops are currently sitting in rice bags and not being used...
  27. E

    Speed regulation: Isochronous vs Droop Control of Generator

    Hi! I am confused with the speed regulation for Isochronous control. In Droop control, we can surely solve for a value of speed regulation because droop allows the generator to have a varying frequency. However, in Isochronous control, the frequency and speed from no-load to full-load is the...
  28. F

    Need Spin Wave Generator Circuit Design

    Hello, I have found the technology of spintronics very interesting with a great potential for the (hopefully near) future & I am desiring to experiment with spin waves. I am sure there are several ways to create a spin wave or current, one of which involves placing a platinum strip at the end...
  29. L

    Generate sine wave with signal generator on scope

    I'm new to electronics, and using my new equiptment I would like to generate a sine signal on my function generator and display it on my oscilloscope. Equipment: * The scope is Rigol DS1054Z * Function generator is a $60 digital chinese. My problem is: When I plug connect the function...
  30. V

    Determine the largest current the generator can produce

    Homework Statement A 120-V generator is run by a windmill that has blades 2.0 m long. The wind, moving at 12 m/ s, is slowed to 7.0 m/ s after passing the windmill. The density of air is 1.29 kg/ m3. If the system has no losses, what is the largest current the generator can produce? [Hint: How...
  31. I

    Active aero/active vortex generator?

    So, drag vs downforce on race cars is the equation. We all know vg's will help airplanes from stalling by keeping the air attached past the point of stall. At stall the air has no (?) major drag? (This is a question). So let's say your race car has a flat bottom, front splitter and a rear...
  32. A

    How exactly do motors and generators work by using magnetic fields?

    So I know if you move a charge in a magnetic field it induces voltage and hence a flow of charge is created which is current. ( Please correct me if I'm wrong). But that's pretty basic right. However, I'm having trouble understanding the use of split rings in the functioning of a motor. I would...
  33. J

    Calculate the power generated by a rotating rod turning a generator

    I want to know how much electrical power I could potentially generate by putting a generator at the pivot point of a rotating arm. I figured I can calculate the Kinetic Energy of the arm by: E=(Iw**2)/2 where I is moment of Inertia and w is angular velocity. I = (mL**2)/3 for a uniform rod in...
  34. M

    Kinetic energy to electrical energy generator

    I am going back over the topic of electricity and energy. I am just wondering within a kinetic energy generator what is the relationship between the speed of the rotating shaft and the overall electrical output of the generator. Thanks
  35. bachir1994

    Emf without load and load voltage of a generator

    HelloLast week I was confronted with a situation where an industrial equipment, with a large equipotential mass (metal casing) that was not grounded, had a ground tension, measured with Fluke, of 382 vac. I put a 220 Vac bulb and nothing happens, the bulb remains off and is not burned out. By...
  36. C

    Upgrade Your RV Inverter: Choosing Between Inverter or Generator

    Hi my name is Clay and I'm thinking of increasing my inverter in my RV ,from 160w to at least 1800w Invertor...($900) so I can run a oil heater at 750w drawing 2.3 amps or a Nutri bullet juicer rated at 900 watt, not sure what amps this draws, I have four solar panels on the roof and each one...
  37. O

    In a basic series-wound generator, what is "load voltage"

    The statement I read is: Because of the way that series-wound generators are constructed, they possesses poor voltage regulation capabilities. For example, as the load voltage increases, the current through the field coils also increases. This induces a greater emf that, in turn, increases the...
  38. bachir1994

    Choice of a generator set for a drilling pump

    Hello everyone, I am faced with a problem where I have to power a 30kw drilling pump, with a generator of 45kw (model Gesan), but it does not work. At start-up the current reaches the peak of 190 A and descends gradually, for information the start-up of the pump of the drilling is done by a...
  39. SeaDawg

    Need help for project plans (Solar and Wind Generator)

    Hi, I'm trying to build an auto-sufficient station, this is my "blueprint" for mounting everything together : https://goo.gl/photos/4KLmhUc9EDccMPkYA and I would like to know if it was possible to calculate the voltage and intensity entering the Charge Controller without measuring it, if...
  40. Asmaa Mohammad

    The average EMF in a coil rotating in a magnetic field

    Homework Statement [/B] Homework EquationsThe Attempt at a Solution Solution for Q1: Solution for Q2: Solution for Q3: Are they correct?
  41. Ahmad Esber

    B Is it possible to harvest energy from fluid buoyancy?

    So I've noticed my little sister's helium balloons floating at the ceiling. Made me wonder if someone could create a device that could harvest energy from this buoyancy. What if I tied a very long rope to a huge balloon filled with helium, and rolled the other end of the rope to a gear attached...
  42. Manoj Sahu

    What generator should I buy for charging 12V battery?

    I have to charge a 12V 7AH battery using a wind turbine. For this purpose what kind of battery should I employ?
  43. R

    How to measure the output of a generator

    I am doing a math project. Our goal is to use Mathematica to design some small wind turbine blades, 3D print them, and then attaching it to a small dc motor. I did something very similar for science Olympiad, where we had been measuring the "power" by measuring the voltage between the two wires...
  44. Asmaa Mohammad

    Which drawing represents an AC generator?

    Homework Statement A magnet bar has been installed in the vertical rotation axis of a coil. Which of these drawings represents an AC generator? 2. Relevant rules Fleming's right-hand rule.The Attempt at a Solution Fleming's right-hand rule assumes that the coil is in motion, but in the...
  45. Nikhil N

    Optimizing Gate Drive for High Voltage EFT Generator Design

    I am trying to make a EFT generator in low cost which can generate bursts specify by IEC61000-4-4. The circuit which I am working on is given as below. This is for making a high voltage of atleast 400V. I got this design from a paper. But it is not mentioned the values of R1 and R5. I am not...
  46. D

    Seebeck generator from placing water heater next to freezer

    Water heater is set at 130 degree f freezer is 5 degrees f. Is it possible for a thermoelectric generator to collect energy from these placed side by side? Would the extra energy used by the heater and freezer due to the presence of the generator cancel out and then some any energy that could...
  47. G

    Homopolar generator: disk vs. helix

    Hi, I'd like to build a homopolar generator. Since generating magnetic fields of uniform density of any useful size is very tricky to do with off the shelf permanent magnets (I've tried!) I had the idea to use DC solenoids instead. But with a rotating helical plate in place of the cylindrical...
  48. Undacuva

    Why Do Generators Use Coils Instead of Pipes?

    Hi, I understand you can induce an electrical current by passing a magnet through a copper pipe. If so, why do generators (and motors for that matter) use coils in stead? Do coils allow a stronger current or greater efficiency? Where can I go to find out the most energy-efficient design for a...
  49. P

    Can you create a hydroelectric generator using a pump from a fire fighting pump

    wanting to know if you could create a hydro system using an old firefighting pump discarding the old petrol or electric motor and replacing it with an generator or alternator. water would flow into the pump which would drive the generator
  50. P

    How do I design a Permanent Magnet Synchronous Generator?

    Hi, I'm trying to do a very simple analysis on Simulink where I am applying a speed to a Permanent Magnet Synchronous Generator with a purely resistive load. I'm not familiar with PMSGs so the results I'm getting don't really make any sense to me. Could anyone go through some simple design...
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