Ac Definition and 1000 Threads

Hey guys, My understanding of circuit analysis and the like is very minimal, and I have had a certain lack of understanding about something for a long time, and I feel I need to get a solid answer. I understand the fundamental difference between a voltage or potential difference and a...

Hi, I have to detect overvoltage on each of the 3 phases (individually) of a 3 phase AC signal. The 3 phase AC source has a neutral that is grounded and I have to use the same ground plane for my PCB. I was thinking of using a full bridge rectifier for each of the 3 phase but the problem is...

Homework Statement I need help with determining the current through the 1Ω resistor. http://img403.imageshack.us/img403/5422/acex22.jpg The trouble I have is that the voltage sources are phased as given in picture, and I got stuck on how to deal with these phases when calculating the...

Hello experts! AC emitter resistance is given as, rE'=25mV/iE My question is that what does this 25mV tells us? and where does it come from? Thanks in advance.

Hi there I have an Photo Voltaic system size 141 kW DC. It gives me an about 13 000 kW/hr a month.(I'm in Hawaii) We planning to install a new system, size ≈800 kW DC. How can i calculate how much of kW/hr AC i will get out of new system? Is there is any special formula to covert DC to AC...

I am sorry if this may seem like a beginner question (which I am not) but the I find the best way to learn something is to understand it from it's most basic components or operations first. In this spirit I have a question regarding the relationship between voltage and current in AC circuits...

Hello experts! I am the student of electronics engineering. I have an question related to AC and DC button in Oscilloscope. When I am performing practical then I don't know whether I switch oscilloscope output to DC or AC mode. When I ask to teacher they don't give me any satisfaction for...

I know the mathematical and geometrical reason, but does there exist a physical interpretation behind this? Thanks :smile:

Hello folks. I have an electromagnetics quiz tomorrow and I am kind of nervous. I can't seem to grasp the concept of induction, more importantly how it differs in AC and DC circuits. So in lay terms: Induction is production of electric current across a conductor which is moving through or...

What is the main frequency components of noise from AC line, florescent lights, appliances and other common household stuff? I know there are 60Hz and 120Hz from rectifying. Do I have to worry about 180, 240, 300, 360 ( 60X1, X2, X3, X4, X5...) etc.? Which one are the strong ones?

Hello, an elementary question here. I am thinking about a BJT transistor amplifier circuit which has the usual AC coupling capacitors to allow the AC signal to pass while isolating the DC component. I understand that but my question is how is this decoupled AC signal represented on the actual...

What is it that causes pulsed dc into an inductor to turn into ac? Are their specific frequencies at which this occurs (i.e. inductors self resonance frequency)?

Hello guys! This is not quite a homework, but anyway. Homework Statement I'm trying to figure out some details about the circuit below. The circuit contains two voltage sources. V1 is 5V 100Hz AC source, V2 is 15V DC source. I know I can analyze this circuit simply treating it as if there...

Homework Statement A 200? resistor is connected in series with an AC generator that produces a peak voltage of 10.0V. What is the peak current through the resistor if the frequency of the source is (a) 100Hz and (b) 100kHz Homework Equations V=IR The Attempt at a Solution I just...

Homework Statement Using an AC signal generator vs, a transformer with turns ratio n = 1, and a battery VB, sketch a circuit that will generate the output signal vout = vs + VB Homework Equations \frac{V_2}{V_1} = \frac{N_2}{N_1} The Attempt at a Solution Here's my sketch...

How would the magnetic field of a solenoid change if it used AC current instead of DC current? How would this affect the motion of a charged particle moving from the center to the side of the solenoid? This isn't a homework problem, just something I'm curious about. Hence, there is no "right"...

This problem just occurred to me while I was taking photos indoors: Light sources powered by mains fluctuate in intensity due to alternating current. In other words, a lightbulb will actually flicker on and off at 50Hz/60Hz (or, really, 100Hz/120Hz, since I guess it should be the absolute...

Homework Statement The sinusoidal voltage source in the circuit shown in Fig. 2 is developing an RMS voltage of 2000V. The 4ohm load in the circuit is absorbing 4 times as much average power as the 25ohm load. The two loads are matched to the sinusoidal source that has an internal impedance of...

Hello. I'm am studying topics related to inductances and Faraday's law and I'm having hard time at PICTURING situations. Mental representations. So I propose an example of something I don't understand and we may go on from there. Consider circuit consisting of an inductance and an AC source...

[b]1. Hi everyone, i was given an AC circuit (capture.png) and am required to find the value of the variable resistor Z so that average maximum power is delivered to it. To solve this i am trying to find the thevenin equivalent circuit but i am stuck and unable to figure it out. Any help would...

Homework Statement Given a triangle ABC with ∠ B = 60°. The bisectors of angle A and C intersect BC and AB at D and E respectively. Prove that CD + AE = AC. Homework Equations The Attempt at a Solution I stuck on this question for hours already... what is the trick of proving...

I plan on using a very large solenoid for a magnetic field experiment. I have estimated what I believe to be the inductance and resistance of the solenoid and, with the desired field to be produced, almost 20 amps will be required. After running a simple simulation, I am not sure how to...

What happens if an big AC induction motor is running with full load an your suddenly reverse the 3 phase?

What will happen if an ac inductions motor is running, an suddenly an error occurs in the voltage pr. hertz motor control so the stator frequency goes down below the rotor frequency for 1-2 sec?

Hi, I have a Mains AC 251v to 220v transformer connected to my house. I am thinking of installing a solar power grind in system rated at 240v output. What would happen to my mains transformer if i connect the 240v supply to the secondary side at 220v of my wiring therefore having 2 different...

I have a push-button switch rated at 3 amps @ 125vAC which I want to use in a 12v DC application (my motorcycle). ((on ground line under continuous use {headlight})) Does the AC rating translate as 3 amp for 125v AC hence 375 watts 375 watts for 60v AC hence 6.25 amps or 375...

Hi all. A transformer is driven with a square wave pulse. The transformer has three secondary coils all in series, a diode is placed between two of them which is forward biased during the on time. The coils are used to charge a capacitor and limit current. When the transformer is pulsed...

General enquiries (template may not be suitable) - When the question provides value of AC voltage amplitude, is this the same value of peak voltage? - Also, in current waveform, when do we use peak current and rms current? - In ohm's law equations we use rms current, so in the current...

Hi, I've been reading papers about the influence of high voltage overhead AC power lines on steel pipelines that run parallel to the power lines in the same right of way (that is near the power lines). The pipelines are coated in a dielectric coating to prevent corrosion and can be above...

I would like to ask how to change the frequency of the ac supply (frequency = 50Hz) to a ac with a very high frequency. Does anyone suggest any materials or websites for me to reference? Thanks.

Homework Statement A complex AC voltage is given by the equation v = 3e^j450t : Note the use of bold v to represent the complex voltage. For this voltage waveform, what are the values of -volltage amplitide -frequency -instantaneous voltage -graph it in a argand diagram at t=pi/1800 Homework...

Homework Statement A 2000 turn solenoid of length 1.50 m and diameter 5.00 cm has a dc resistance of 3.0. It is connected to a 50 Hz, 40.0 Volt (rms) ac supply. Find the rms current in the solenoidHomework Equations Vind = L di/dt Vind = Induced EMF Ohm's Law V-Vind = IR L = (4pi x 10^-7)n^2 Al...

What are the benefits of having Alternating current instead of direct current? I'm just wondering why we use AC instead of DC..

Hello I am a EE student and was wondering if anyone had some suggestions on how to fix my inverter it's for a capstone project we are using a twelve volt battery and trying to get 120vac 60Hzs we can get 59Hzs from the curcuit intill it goes into the transformer then it changes to 177Hzs and...

I recently simulated a parallel resonant tank circuit on multisim. I put an oscope across the tank circuit and I get an AC signal, but what interests me is that it is amplitude modulated. The oscillations slowly build up in amplitude, hit a peak and then die back down. I think that the...

In an a.c.circuit containing only inductance, for example, it is said that the current is lagging behind emf by 90 degree. We can understand this that when the emf is zero,the current is at its negative maximum and when the emf reaches its positive maximum, the current becomes zero and so on...

Hello all- I'm not very keen on electricity but am hoping this question is simple enough somebody might be willing to help out. I have a device that runs on 120v ac. Inside the device, the power supply converts the current to 1 12v-, 1 12v+ and 2 5v+. I'd like to remove the AC power...

Hello EE, I currently have a mini project that Studiot provided me with. Project is a kind of a multi-functional tester. But I want to add another feature to that tester. That tester has a 9V DC output, which gave me an idea. I always find myself searching for batteries and other power...

hi i have question related to torque = force X r = Fr sin (theta) and torque = k (Br X Bs) = k BsBr sin (theta) why does theta the same in both ??

pls explain me the concepts of ac ground,dc ground and virtual ground.?

Hi. New to the forums so bear with me. I am trying to calculate the magnetic field at a distance r from a wire carrying a 495Hz signal at 8Vpp and current 0.8mA. Initially I tried ampere's law, but fell into the trap of using the un-modified form (without maxwell's correction). I know that...

I want to know the function of the two power amplifier ?

A sine wave source charge a capacitor through a diode. Is it more efficiency than a DC source charging a capacitor ? base on this https://www.physicsforums.com/attachment.php?attachmentid=17653&d=1235114409

I am confuse at a point that is: I equation P=IV there is an inverse relation between I and V But according to ohm law there is direct relation between I and V. How in in ac Power transmission line 1100 volt cause small current than 220 volt... please solve my this trouble... Everyone...

I understand the difference between AC and DC, and i also understand how an AC transformer works... but I guess not completely. My question is why can't a DC use its emf to create a lower voltage current like AC can? Does the DC's emf accrue over time thus making its transformation short...

I'm a mechanical engineer and I'm really interested in electrical systems. I understand a fair amount about the basics of E/M and circuits. But no matter how much I read, I can't wrap my head around how AC systems generate power. I do know they work (obviously, right?), but I'm trying to imagine...

Homework Statement http://img34.imageshack.us/img34/9415/rock1x.jpg Shaft's AC movement is regulated by runways A and B. The angular velocity of the shaft is 3 rad/sec, counterclockwise. When angle psi = 40 degrees. Calculate: A) The velocities of pistons A and B (Va, Vb) B) The velocity of...

what is the force between the two (AC) current carrying conductors??) in case of dc currents,they repel or attract when the two conductors carry current in the same or opposite direction,what about two wires carrying ac currents.:smile:

Just to clarify the title... Basically for the below circuit we are required to find Vth, Rth and Vo. However, the method of solving this problem is a little strange to me, because as you can see, the source has a phase angle of 30 degrees. The solution to this problem basically says (to find...

Need reduce 220V AC to 24V AC without transformator and I'm not sure about circuit. Should I use resistor? Title is wrong (AC-AC) Thanks. [title corrected. -Russ]