Dc Definition and 1000 Threads

Why is AC more dangerous than DC even if the peak voltage of AC is the same as the DC voltage? This is a problem from our exam. Before I read the question I always thought that AC is more dangerous than DC because at the same voltage, AC voltage is higher as it has a peak voltage than DC. I've...

Homework Statement Hello i just have an interesting question, and was wondering if my answer to it had any validity. Ok so i did an experiment The Current balance experiment(for everyone not familiar with it, you can google it and get all the info you want) to try and estimate mu naught...

Hi guys, first post here. I am an Electrical Engineering student (2nd year) and I have a part time job doing qualification and FMEA type work on power supplies. It's been a great learning experience and it's really helped me in my classes. Right now, I am doing a qual on a low voltage dc...

I am constructing a small wind generator for a college project. I want the 0.1 V AC output of the generator to charge a battery. To do this, I need to convert the current into DC. I am familiar with things like bridge rectifier circuits, but the smallest diodes I can find have a forward "turn...

Hi sir, I am new about to this site.Actually I am an embedded engineer. Right now I am working on :smile:Pick and place robot.I want to control dc motors. I don't have any datasheet of DC motor.But I want to know how to calculate dc motors parameters required for the moments of robot.Right...

Torque has an inverse relationship with motor speed and I can understand why it's like that (more speed = more cemf = less current = less torque). On the contrary, my SCR controlled DC drive manual said that a DC drive could control a DC motor in a way that give constant torque from 0 rpm to...

Hi all, I have recently observed a very strange thing (or rather, I shall say unexpected phenomenon). When I deposited some charged micro-particles between 2 electrodes (vertical plates) with a DC bias in hexadecane oil, I expected the negatively charged particles to go to the positive...

what is meant by dc equivalent circuit and dc load line analysis? why we require these two ? advanced thanks.

Homework Statement The circuit in the figure is composed of two batteries (e1 = 8 V and e2 = 6 V) and four resistors (R1 = 110 W, R2 = 40 W, R3 = 30 W, and R4 = 50 W) as shown...

Homework Statement 1)Rank the brightness of the bulbs. 2) What happens to the brightness of the bulbs when A is unscrewed and removed. 3) A is unscrewed, what happens to current through 3,4,5. Red circles are bulbs and the black circles are reference points. The Attempt at a Solution 1) I...

I know the magnetic field makes a circle around a wire with current flowing through it. So I wondered if a motor could be made in the following way. Take a round plastic sleeve with an inner diameter slightly more than the wire. Glue 4 magnets on the sleeve, such that they form a circular...

Homework Statement Find the voltage across the capacitors in the circuit given under DC conditions.Homework Equations V=IRThe Attempt at a Solution The solution is already given (the picture attached was obtained from the solution manual. I have a difficult time understanding how they arrived...

I'm an entry-level engineer, and I have a design question for the forum: I'm designing a multiphase buck DC/DC converter which will convert roughly 65VDC to 52VDC at up to 150A. I'm using 4 phases, so inductors, etc will be designed to about 40A/phase, MOSFETS will be paralleled for less...

DC Blocking capacitor -- How does it know where ground is? Hi Everyone, A DC blocking capacitor removes any DC offset from an input signal. I've been doing this for years without thinking about it. My question is, how does it know what the local ground potential is? My only thought on...

Homework Statement The positive terminals of two batteries with emf’s of E1 and E2, respectively, are connected together. Here E2 > E1. The circuit is completed by connecting the negative terminals. If each battery has an internal resistance r, the rate with which electrical energy is...

Hello, I'm building a DC generator for fun (of the cardboard and lego variety). It is based on this model: How would you calculate the power output from that, assuming we know the strength of the magnets and the frequency of rotation? Are there any easy ways to increase...

Hoping that one of you electrical wizards may be able to help me out! I have a 30A DC HP power supply and a 1000W stereo amp that I want to use create a 10mT static DC magnetic field superimposed on top of a 1 mT AC magnetic field. To generate the AC field I have a 1 uF snubber cap. in series...

Hey guys, just a quick question, what would a graph from 0 < x < 360 for magnetic flux look like for a DC motor, where the coils initial position is parallel to the magnetic field.

Hey guys, I have a DC motor and i want to glue to it's rotor a round plate (make a hole through it and stick the rotor in that hole :) )(consider the plate weightless) and on this plate i will glue a weight, doesn't matter what the weight is...just know that it's constant. My question is this...

Ey guys sorry if this is in the wrong area; not too sure but i do mechanical eng and figured it was. Well i hope so lol otherwise i might have selected the wrong course We have an assignment coming up, (according to past year students that involves DC motors, gear box's). Wouldn’t mind...

Homework Statement Hello all, I just have a quick question regarding the modeling of the following circuit (see attached). I am trying to derive the equation for the voltage across the capacitor as a function of time. I come up with the correct result when the element polarities are the same...

I have created blueprint for a DC generator.THEORITICALLY it is 100% power efficient,it involves no AC in PRODUCTION,i need to know whether AC devices we work daily cope up with dc power or not?

Suppose you want to look at a square wave signal riding on top of a large DC bias. This seems like it should be simple, but I was thinking about this today and I don't know how to do it. Normally, one would remove a DC offset with a high-pass filter (or just a capacitor). However, with a...

i need link for the power or the maximum current for dc battery 9 and 1.5 voltage ..if anyone know please share it ??

how to convert dc voltage into higher dc voltage using transformer? i am tring to convert 9 volt dc into 120 volt dc , and i ve to use transformer ,,, the problem is the transformer must have input ac voltage as it work on flux variation . i think the solution is to convert the input dc into...

Homework Statement In one of my labs for a circuit analysis class we are told to design a simple DC power supply. The power supply will have three outputs, +4.5V, -4.5V, and an adjustable output from 0-11V. I have already done most of this and the question I have is could you design this so...

In a field loss event, why does a shunt wound dc motor run away? From my understand of electric motor, the armature spins because it's magnetic field pushes/pulls against the field winding's magnetic field. If I remove power to the field winding, then shouldn't the motor slows down because the...

Hello, I'm doing my thesis on dc motor position control, using the Simulink's Real Time windows target.The dc motor is Faulhaber 2342024CR(DC micromotor). First of all, I need to simulate the motor so as to have a full simulation of the whole system(motor,servoamplifier). The problem is that...

Why is it that AC is superior to DC in long distance power transmisson. I was thinking it has something to do with the resistance of copper wire but if this is the reason then why is that? Or, why is copper loss not a factor with AC current? Thank you!

Just curious why the red & black leads from my multimeter get quite warm when measuring higher dc current under a 20A setting? First I measured 4-5amps for 20secs & the leads didn't get warm, then measured another system with 16-17amps draw & within 5 seconds it got quite warm. Not like its...

Homework Statement [PLAIN]http://img695.imageshack.us/img695/206/95144436.jpg Homework Equations Hand rules The Attempt at a Solution This is a practice question with the answer already given in the diagram. I know how to draw the coils and use the left hand rule to find the...

Homework Statement R1 = 9.29 V= _____ I = _______ R2 = 9.19 V= _____ I = _______ R3 = 8.45 V= _____ I = _______ R4 = 4.47 V= _____ I = _______ R5 = 9.12 V= _____ I = _______ R6 = 4.60 V=...

I have been researching generators lately, whilst contemplating building my own wind powered generator. I think I understand the general layout: a central magnetic core that rotates with an outside ring of conductive coils spun in specific alternating turns with their own magnetic cores. If I am...

Hi all :) As the title says how do Ac and DC affect the body differently? Also if anyone knows the answer to these questions as well I'd REALLY appreciate it :) 1.How electric current and magnetism interact 2.The effect on frequency on the impedance of a capacitor and the impedance of an...

On a low-voltage DC Solar system(up to 48V nominal), should I leave the lines floating or one should be grounded? I don't see any real advantage on any option...that's why I ask to confirm

Homework Statement Hi, well my task is to construct a DC motor. With 25w rotational mechanical output power. It cannot draw more then 5A current, and has to have 3 or more poles in rotation. The motor must be brushed/commutated. There is a max of 30v D.C. input. The motor needs to be built and...

I am trying to drive a 5V DC motor using a MCU output. The motor is run directly off the +5V line which is down-converted from 18V using a TPS5430 Step-down converter. The MCU coding is basically that when the inputs are in the correct state, the output to the FET turns on for a number of...

tell me something about DC offset component in reference toshort circuit fault current

Hi there, I have a question on DC generators stator assemblies?? I've been given a standard DC alternator wye wound stator assembly wiring diagram as attached. The question states: terminal at point A is nominated as, answer, (A) "STA", (B) "AUX" or (C) "POS"?

Which is most dangerous for human being 230 V ac or 230 V dc voltae supply

Which would be more dangerous for a human being 230 V a.c or 230 V dc supply...

If i have a light bulb , and it has a tungsten filament and when i turn it on its gets hot , If i hook a lead to the filament and then put the anode away from the filament can i get electrons to flow through the vacuum , assuming this is done with DC current. If we used 2 different...

Homework Statement The ratings of a dc generator are given (16 kW, 250 V, and 64 A) when it rotates at 1000 rpm. Then the question asks to find the no-load voltage at 1000 rpm when there isn't a circuit hooked up to the generator. Homework Equations P = IV V = IR Kirchhoff's circuit...

Dear all, This question is related to the radiation of a UWB antenna. If I feed a Gaussian pulse to a UWB antenna, would a differentiated gaussian pulse radiated? It seems so as in the tutorial paper (attached) by Wiesbeck says that "any antenna differentiates any signal because antenna do...

Hi, I am attempting at making a simple device that will run on dc power that just spins a item i place vertically in the air. I am trying to do it without having to by any of the parts being i could just buy a new one for around 250 bucks. My first question is how to you determine the...

Hi all, i am working on an 110W inverter (Dc to AC) project that the input voltages varies from 700Vdc-1000Vdc and the output voltage is 220Vac. The system operates, however i have problem with output choke. The output choke temperature increases instantly even in no load operation. My...

Hi, Its great to see a forum like this thanks for your efforts and thinking that PF can help me a lot. I Am ANANTH pursuing 3-2 B.TECH under J.N.T.U.H i am working on a project of wind energy to electrical energy. but the problem is what type of dc generator(rating) should i use? first I've...

Hello all, This is my first post in this forum. Hope can get some constructive help from the community. I did some testing with some radios which is actually a double ended circuit (BTL), meaning it has the spk+ and spk- port. When I want to connect it as a single ended circuit, meaning...

if the inductor is at dc steady state, the inductor would act like a short. in this case, why would the voltage across the inductor be zero? thanks in advance.

Homework Statement Explain why A.C. is used instead of D.C. to transfer electrical power from the generating station to the consumer. Homework Equations The Attempt at a Solution To reduce the energy lost in long distance transmission. To reduce costs involved in transferring...