# What is Ac generator: Definition and 48 Discussions

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. ### Understanding Electric Shock in Floating-Neutral and Floating-Ground Scenarios

Hello, let's say the AC generator and the washing machine, with a live metal frame due to a fault, are floating-neutral and floating-ground. These are many combinations where both get and get not bonded/grounded. Can anybody tell us in which case the person gets an electric shock when touches...

3. ### AC generator, current and ground

Hi, Let's say we have a basic AC generator, where a single wire is rotated within two magnets: Due to the electromotive force, a voltage is generated so that Va - Vb = 120V. Let's now ground Vb side directly to earth, while leaving Va still open: We can say that Vb = Vc = 0V and Va...
4. ### Magnets with Halbach array in an AC generator

As a project, I am demonstrating electromagnetic induction by making an AC generator. The magnets I currently have access to are very strong neodymimium countersunk magnets, but I noticed that they utilise a Halbach array. I am aware that this means the magnet has alternating N-S poles spaced...

Imagine a magnet moving up and down so that its flux 'B' cuts the copper rod to produce an alternating emf, suppose if the movement is fast enough such that its frequency equals to the electron spin resonance frequency given by F = B x 2.8 Mhz per gauss, neglecting skin effect, more copper...

7. ### Maximum Induced Voltage of an AC Generator

I would like to ask a question about the induced voltage of an AC generator. So, according to a graph I found on Google, the maximum induced voltage is reached when the loop is parallel to the loop. (The graph shown below.) Then I was wondering, what if the loop is initially (when it is at 0...
8. ### Determining Number of Turns for low voltage AC Generator

Ok, I did a quick search, and could not find answer. I need to determine how many turns / windings of 24awg magnet wire are required to generate no less than 5VAC no greater than 20VAC single phase using 3 of the N45 Neo Magnets rated at 13800 gauss each with 275-pound pull. Y'all give me a clue...
9. ### Magnetic Field of an AC generator

Hi Please help me in understanding the kind the magnetic field used in an AC generator. Most of the figures (one shown in attached file) are shown with concave poles. Hence the field has to be radial. In such a field the angle between plane of coil and the magnetic field remains zero all the...
10. ### AC generator output voltage to grid question

Hi, In a given area there are different types of power plants , let's assume they are (coal, nuclear, wind and solar) Now as I have learned most of these plants (except solar and some others) use synchronous generators as the last step between mechanical energy conversion into electricity. But...
11. ### AC generator -- Understanding coil voltages as function of position

Homework Statement In an ac generator Voltage is maximum when the coil is parallel to the direction of magnetic field (B) Voltage is minimum (0) when the coil is perpendicular to the direction of magnetic field (B) I'm trying to understand why. Homework EquationsThe Attempt at a Solution A...
12. ### 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...
13. ### 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...
14. ### Current Rating of an AC Generator

Hello, I'm a bit confused on the term current rating in an ac generator. Is it the one in that I can get in the formula: kW= V*I*PF*sqrt(3) ? or the one in kW= V*I*sqrt(3)? The problem is the data that I have is V, PF, kVA only. I can compute the kW using those data but I'm abit confused on...
15. ### Find the maximum voltage of an AC generator

Homework Statement The sinusoidal voltage output from the AC generator oscillates between 500 V and -500 V. The circuit for an ideal transformer is constructed with a generator, transformer and a 30 Ω resistor . The generator makes 4 loops with the transformer and the resistor makes 9 loops...
16. ### How does rotating a magnet affect the magnetic field?

I'm doing an experiment on the effect of the speed of rotation of a rare Earth magnet on the voltage generated in a solenoid coil. I was wondering, how does rotating the magnet affect the magnetic field? The experiment setup is similar to the one below:
17. ### AC Generator With Repelling Magnets

Hi Everyone, I have 4 scenarios in question . Will The EMF(Voltage) be the same in all of the scenarios? - the difference between the two photos are the polls: one repel one attract . - i understand that the current(amps) will change due to the wire length assuming same gauge 1) Photo...
18. ### AC Generator Design: How to Increase Output Safely

If you buy a generator (gas powered etc) there is only a certain amount of watts that the generator can put out. This is because the engine only has a certain power rating (and losses). However, if one were to put a higher power engine on the generator head and remove the safety breaker for...
19. ### Induced Current in an AC generator

Homework Statement This is a simple inquiry, based on what my textbook has told me. "...the amount of induced current also depends on the angle of the conductor in relation to the external magnetic field. The induced current is at a maximum when the plane of the loop is parallel to the...
20. ### AC generator calculation question

1. Calculate the emf induced in ONE side of a coil of length 0.4m and width 0.3m, when there are 50 turns in the coil and the flux density is 96.8 mT, and the coil is rotated 30 degrees from the vertical. Frequency is 50 Hz and the long sides are the ones facing the magnets.
21. ### AC generator on grid: Governor and Amp

Hi Forum, once again I seek your help I have a very good understanding of rotating magnetic field due to stator, armature reaction, and the phasor diagram. from energy point of view it is very clear that if Gov increases, while output voltage remains locked by the gird, Amp will increase...
22. ### Electric AC Generator: Understand Magnetic Fields & Brushes

Hi! I have been studying AC generators. I am confused about why there is no current when the armature is perpendicular to the magnetic field (when it is vertical). Also, what is the purpose of the brushes? Probably a really obvious answer, but it is confusing me. Any help would be...
23. ### Max EMF in a Model AC Generator Coil

Homework Statement In a model ac generator, a 500 turn rectangular coil, 8.0 cm by 20 cm, rotates at 120 rev/min in a uniform magnetic field of 0.60 T. (a) What is the maximum emf induced in the coil? (b) What is the instantaneous value of the emf in the coil at t = (∏/32)s? Assume that...
24. ### AC generator and DC motor problem

Homework Statement For an AC generator, my teacher told us that when turning it, you will slowly manage to turn it at a constant speed only because of the induced current causing a force in the other direction to the turning motion. Why is this so? For a DC motor, my teacher told us that after...
25. ### Calculating the Power Output of an AC Generator.

Hello everyone! This is my first time posting here and I hope I can make a good first impression, and I apologize for the lack of links because of this being my first post. Currently I am working on a project for my grandfather's engineering business, and part of this project is designing a...
26. ### Significance of number of magnetic poles in ac generator

I am supposed to discuss the benefits of having high number of magnetic poles in ac generators with constant frequency. From formula it is obvious that the higher number of poles the lower the speed of rotation. But is there anything else, or what is the benefit of lower speed? The only...
27. ### Experimenting with 24VDC to AC Generator Output

Hello, I am new to this site and thought I would give this a shot. All my experience is in low volatge DC circuits and don't have a whole lot of experience dealing with AC but I am trying to learn. My boss and I are working on an experimental generator with 24VDC input but AC output...
28. ### Why is there an induced current in a dc motor?

When I put a current into a dc motor, there will be a turning effect. But I thought as this happens, won't there the an induced current that flows in the opposite direction? Bt Fleming's Right hand rule, the current will flow in the other direction. So I'm quite confused about this...
29. ### Exploring the AC Generator in an LRC Circuit

Homework Statement An AC generator in an LRC circuit produces a voltage V(t) = 1.414sin(wt) = 1.414sin(1000t) The values of inductance, capacitance, and resistance are shown in the diagram. Recall the w = 2pi*f. i made a picture of the diagram...
30. ### Step up transformer + ac generator question

Homework Statement An AC generator, originally designed to provide a peak output of +/- 155V at frequency 60Hz, is required to provide a peak output of +/- 340V at 50Hz. If the generator is connected to a transformer with 200 loops in its primary coil, how many loops should there be in the...
31. ### RMS Current in an AC Generator with Doubled Rotational Speed

Homework Statement The output voltage of an a.c. generator is \emph{V}=\emph{NBA}\omegasin(\omegat). When the voltage is connected across an inductor, the rms current in the inductor is found to be 10mA. What will Be the rms current if the rotating speed of the coil inside the generator is...
32. ### AC Generator with Resistor: Exploring Kirchhoff's Loop Rule

Homework Statement A resistor of resistance R is connected to an AC generator with EMF(t)=(EMF_max)sin((w_d)t). (a) Write Kirchhoff's Loop Rule for this circuit at a particular instant of time. Is your result a differential equation? (b) Find the current as a function of time. Now...
33. ### Is a Small AC Generator Suitable for Running Electronics?

Hi all, The country where I live, electricity outages are a part of life, so to compensate for it I have a small 2.2kW 220V AC generator in my house. The problem with it is that I've heard and found out for myself that its output is unfit for running electronics. Testing with a...
34. ### Calculating Resistance and Input Voltage in an RL Circuit with AC Generator

Homework Statement A resistance R and a 1.4 H inductance are in series across a 60 Hz AC voltage. The voltage across the resistor is 30V and the voltage across the inductor is 40V. (a). What is the resistance R ? (b). What is the AC input voltage ? Homework Equations \xi=I*Z The Attempt at...
35. ### How Does an AC Generator Produce EMF?

Homework Statement Need to draw a graph of the emf generated by a simple single-phase generator which has a coil of 200 turns. The coil is 14cm long and 9cm wide. The magnetic field in the generator is 0.15T. The generator coil is turned at a rate of 3000 revolutions per minute. Can someone...
36. ### Inductance in an AC generator.

I just have some confusion about whether or not self-inductance will occur in an AC generator. The current is alternating in both direction and magnitude rapidly when it is generated and this will in turn cause a changing magnetic field around the conductor. This magnetic field will then...
37. ### Maximum EMF in a rotating coil, in an AC generator?

Homework Statement Im currently in my last year of high school, and I'm writing a report on AC generators. I've heard a number of different things from different sources. When the coil is perpendicular to the magnetic field, maximum magnetic flux is flowing through the coil. This is then at a...
38. ### Current vs. Time: Mathematical Expression for Hippolyte Pixii's Dynamo

Consider a simple alternating current generator such as Hippolyte Pixii's dynamo. The current generated by such dynamo can be described as simple oscillating cosine signal. Assuming for simplicity that the max current generated each time a pole of Pixii's magnet passed the coil is (2/pi)0.5...
39. ### Archived Electromagnetic Induction of ac generator

Homework Statement The coil of an ac generator has an area per turn of 1.2x10-2m2 and consists of 500 turns. The coil is situated in a 0.13-T magnetic field and is rotating at an angular speed of 34 rads/s. What is the emf induced in the coil at the instant when the normal to the loop makes an...
40. ### Where do I start to determine where the problem is?

I have a 3 year old ( Chinese) Amico 3300 watt generator run by a 200cc gas engine. The engine works well and the generator turns but no juice is produced. Circuit breakers (110 & 220)are on. I don't have a manual for troubleshootin and distributor is not helpful. Where do I start, to determine...
41. ### How Does a Three-Phase AC Generator Create Voltages?

Although I am comfortable with three-phase circuits in general, visualizing the three-phase AC generator is giving me some problems. I understand that windings are placed 120 degrees apart, but that's about it. Would anyone happen to have a good animation/picture of a three-phase AC generator...
42. ### How Does Capacitance Affect Current in an AC Circuit?

Homework Statement An ac generator with a frequency of F=25 Hz and an rms voltage of 15 V is connected to a C=32 µF capacitor. Assume that the generator produces a sinusoidal waveform. (a) What is the maximum current in the circuit? mA (b) What is the current in the circuit when the...
43. ### Max EMF Induced in AC Generator?

Homework Statement The armature of an AC generator is rotating at a constant speed of 30 revolutions/second in a horizontal field of flux density 1.0Wb/m^2. The diameter of the cylindrical armature is 24cm and its length is 40cm. What is the maximum emf induced in the armature having 30 turns...
44. ### Solving AC Generator Problem: Find Voltage Output

Hello guys I am having a problem understanding the wording of a question, perhaps someone can help me explain it. The alternating voltage of a generator is represented by the equation E = Eo sin wt, where E is in volts, Eo = 346V, w = 685 rad/s, and t is in seconds. Find the...
45. ### Current/Voltage in an AC Generator

I'm slightly confused about something. In an AC generator at one point in the revolution it produces a positive voltage or current, and then in the other half of the revolution it produces a negative voltage or current...what I'm confused about is which is it producing negatively - the voltage...
46. ### Converting frequency to current for an ac generator

before anyone has a good laugh at me, I am studying environemental engineering and have to do a course that has some electronics it. i have a single phase alternating current (50 Hz) generator that produces 120 volts. I need to calculate the current from this information. can anyone help...
47. ### AC Generator Help: Get Answers for School Physics Assignment

Hey, I need to make an AC Generator for a school physics assignment. It will be marked on how much voltage it generates. I will be doing this using induction with the following equipment: * Permanent magnet * Coil/Wire * Iron Core * Split Rings/Brushes ? My questions are: * What's...
48. ### How do you make a hand powered AC generator?

Does anybody know? The basics? A procedure? Anything i'll be glad with anybody's advice. Thank you.