Ac Definition and 1000 Threads

Michal Áč (born 17 May 1985) is a Slovak football defender who is currently plays for FK Janíkovce.

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  1. H

    What size channel to use to support AC compressor

    I need to replace an air conditioner compressor unit that sits on the 2nd floor walk way on my stilt home in the Florida Keys. The walk way is 24" deep and the original AC unit fit that dimension, however, the new unit is 31" square. When I install the new unit I would like to leave a 18" space...
  2. G

    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...
  3. M

    What is the physical meaning of voltage variation in ac

    hey, i am trying to find what is the process going on in the conductor while conducting ac. what is happening to electrons? what is the physical meaning of negative voltage in sin curve?
  4. P

    High frequency from AC tig welder affects digital ammeter?

    I need a solution to the question, Which clamp-around-the-cable ammeter (digital or analog) can be trusted in measurement of current draw by a high-frequency AC tig welder? High-frequency AC is a requirement of welding aluminum, and an electrician measured 150+ amps at full power welding...
  5. A

    L, E and i: 50.0mH Inductor and 24.0V AC Voltage Source

    A 50.0mh inductor is connected to an ac voltage source of 24.0V.The current flowing in this circuit is 0.60A.The frequency of the voltage source is : a)50Hz b)60Hz c)1.27*10^3 Hz My Work so far ! : f = w/2pi. But here we have L , E and i. Any help will be welcomed.
  6. B

    High voltage Ac generation to apply to a capacitor

    Hi this is my first post on here I am looking to create a large voltage across a primarily capacitive load at around 190 kHz. At the moment i have a 175 Watt power amplifier which puts out 55 Vp. The output impedance also needs to be quite low < 100 ohms Does anyone have any idea how to...
  7. S

    Engineering AC Circuits: Phasors/Polar to rectangular transformation

    40<50degrees + 20<-30 degrees, I get how to convert to rectangular, I got 43.03 + j20.64, but converting it back to polar... how exactly do you do so? The answer is 47.72<25.63degrees... my book doesn't explain it. Also with (2+j4)(3-j5)... how exactly do you tackle this sort of...
  8. J

    Help with physical understanding of AC signal

    My understanding of how AC current works is that the current changes direction, so essentially the charges are oscillating back and forth along the direction of the cable. Then since accelerating charges radiate, this produces an EM wave which is what carries the energy. But my problem is...
  9. D

    Capacitor and their behavior in AC

    I know how capacitors behave when connected to a dc voltage supply. For a simple RC circuit we have the time constant thing come up into the equations and then we can find the exponential fall of voltage and currents. but what I don't get is the what would be the behavior of the same in a ac...
  10. T

    AC vs DC Power Transmission: Exploring the Difference

    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!
  11. D

    AC Circuit Qs: Power & Current w/ 200V RMS

    Now this is not a homework question, just a practise question and my answer doesn't match. An AC source of 200 V rms supplies active power of 600 W and reactive power of 800 VAR. The rms current drawn from the source is ? (the answer is 3.75 while mine is 5) I did was squared and added the...
  12. C

    Ac voltage drop accross power lines

    so the reason why alternating current is used to deliver energy to households is because for a given wire, the voltage drop is always less with ac rather than dc right? but when i calculate the voltage drop it coumes out to be the same! v=IR R=P(length of wire)/(cross section area of wire) i...
  13. A

    The Skin Effect in AC Circuits

    In DC circuits the charge carriers move uniformly through the entire cross sectional area of the wire. In AC circuits the current is constrained to travel in a thin "skin" just below the surface of the wire, effectively reducing the cross-sectional area of the wire. The effect becomes more...
  14. C

    How does a generator produce AC current?

    I just don't understand how it does, because I never noticed the terminals change positions. I understood how DC generators work, but not AC.
  15. A

    RLC AC circuit can't get right answer

    Homework Statement R=250 L=6 C=15microf e(t)=300sin(50pi t) Find Z, phase angle, lead/lag, emf(215ms) (got all of this right) Voltage across inductor, capacitor and resistor, also show that the sum of the voltage across the elements at 215ms is equal to total emf at 215ms. Homework Equations...
  16. T

    How Does Angular Frequency Affect AC Voltage Across a Resistor?

    Homework Statement For the circuit below (attached) plot the amplitude of AC voltage across resistor as a function of the angular frequency of the ac source. Homework Equations ZR = R The Attempt at a Solution I'm not really sure about any of this. Across the resistor, the complex...
  17. B

    How do AC and DC affect the body differently?

    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...
  18. J

    Could Using AC Induction to Separate Aluminum from Food Products be Harmful?

    I am currently looking into using a master magnet to separate aluminum from food products by AC induction. First, does anyone know if this would be at all possible? I know that recycling companies use Edy machines which sound like the same process of seperating cans from other materials. I am...
  19. A

    Reversing Direction & Overheating Solutions for Single Phase AC Motor

    I have an AC Gearmotor W/Fan, Base Mnt, 100 rpm, 7 in-lbs Torque, 115 VAC - I need to achieve 2 purposes with it: 1. Need to able to reverse directions - can I do it with a DPDT? 2. It is overheating - how can I solve it -- heatsinks or fans? Any recommended ones -- I have never done that...
  20. James889

    Then you can solve for the two currents.

    Hai, I have the following circuit: http://img152.imageshack.us/img152/1848/powertransfer.png My task is to calculate the power dissipated in the resistor, and also the power delivered by the V1 source. Here's what i tried. First i /dev/null'ed the second source and calculated the...
  21. H

    How Does Lenz's Law Determine Induced Current Direction?

    Homework Statement An electromagnet is placed next to a coil of wire. According to Lenz’s law, what will be the direction of the induced current in the resistor R in the following cases? a. the magnetic field suddenly decreases after the switch is opened b. the coil is moved closer to the...
  22. M

    Designing an AC Ammeter with 0.15V Voltage and Currents of 200mA, 500mA, 1A

    Hello all! I must design an ac ammeter which uses successive approximation ADC,has a specified voltage of 0,15V and individual entrance resistors for measuring currents of 200mA,500mA,1A. Any suggestions on how to build such a device would be highly appreciated!
  23. N

    230V AC vs 230V DC: Which Is More Dangerous?

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

    230 V AC vs. 230 V DC: Which is More Dangerous?

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

    Fit P(w) to determine Q,w, and R (Series RLC AC circuit)

    Homework Statement Fit P(w) to determine Q, and w_0, and R. You should put in Vrms as a known constant. Homework Equations P(\omega)={\frac{V_{rms}^{2}}{R(1+Q^2(\frac{\omega}{\omega_0}-\frac{\omega_0}{\omega})^2)} Q=\frac{\omega_0}{\Delta\omega} R=R_load+r The Attempt at a...
  26. D

    How to check AC current Through multimeter

    Hai Guys... I want to check the AC current by using digtal multimeter.Please give me instruction.
  27. D

    Dc to AC inverter inductor calculation

    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...
  28. T

    What Is the Correct Formula for Calculating Average Power in an AC Circuit?

    Homework Statement Given resistance of circuit 68 W, I(max) = .191 A, V(max) = 22.5, what is the average power of this circuit? Homework Equations P(avg) = I(avg)V(max) The Attempt at a Solution I took .191 and divided by sqrt(2) to get the rms current and multiplied by the max...
  29. H

    Replacement AC adaptor with much higher current

    Is it bad to replace a regulated AC adaptor that has an output rating of 9V DC and 200mA with a regulated AC adaptor of the same polarity that has an output rating of 9V DC and 1.7A? I know it's OK for the current rating to be higher than needed, but in this case the current rating on the new...
  30. Z

    Why AC instead of DC for Electric Power Transmission?

    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...
  31. H

    117V AC appliance on 127V AC mains?

    In parts of Brazil, the mains voltage is 127V AC. Is it safe to use an appliance which is supposed to take 117V AC in this situation? Thanks
  32. T

    How Can I Connect a 230V AC to a 4V LED?

    hi, im looking to connect a 230V AC to an 4V LED. i was suggested a thyristor could be used then a rectifier to convert AC to DC then using a resistor to drop the voltage to 4V. i dan't seem to understand how a thyristor can aid this process. Any suggestions, please help?
  33. H

    Using a 110/120V Step-Up Transformer for 127V AC to 240V AC

    Hello, How can I use an electronic device that takes 240V AC in an area where the power supply is 127V AC? Clearly I need a step-up transformer, but the only ones I can find convert 110/120V to 220/240V. If I use one of these, will it convert 127V AC to 254V AC (twice 127V)? If so, would it be...
  34. E

    AC Analysis Query Homework Solutions

    Homework Statement I have two questions to two different problems. The first: The Attempt at a Solution My attempt: Thing is, the solutions have V2=4.986\angle111.45(degrees) and i can't seem to get to that answer at all? What is wrong with my attempt because i can't see anything...
  35. M

    AC voltage source in an open circuit

    Please see the attached illustration. This is clearly an open circuit. The voltage source is producing a voltage at some amplitude and frequency. If one were to measure with an oscilloscope the potential difference at the point where the mouse pointer is with respect to the ground, what would...
  36. K

    How to prove sup AC = supA supC Proving sup AC = supA supC

    Fact: If A and C are subsets of R, let AC={ac: a E A, c E C}. If A and C are bounded and A and C consist of strictly positive elements only, then sup AC = supA supC. I am trying to understand and prove this fact, and this is what I've got so far... A, C bounded => supA, supC exist (by least...
  37. S

    Why Can't Well Ordering of Reals be Proven with Dedekind Cuts?

    I know this can't be done but I don't know why. It's been established that the Axiom of Choice is required to prove the well ordering of the reals. Why can't we say that for any pair of real numbers a,b in the set R there exists a Dedekind cut that falls between a and b such that always a>b or...
  38. C

    Electromagnetic Induction in AC circuits

    A 9.7 Ω resistor, a 10.8 µF capacitor, and a 27.9 mH inductor are connected in series with a 120 V (rms) source with variable frequency. (a) At what frequency will the current be maximum? Hz (b) Find the maximum rms current. A (c) Suppose you now replace the 10.8 µF...
  39. W

    What to do with a DC to AC power inverter?

    I recently acquired by accident a 750 watt DC to AC power inverter, designed for powering AC appliances off of a car battery or other 12V power source. I have no need for such functionality. I am really interested in high voltage projects and I was wondering if there are any interesting...
  40. W

    What to do with a DC to AC power inverter?

    I recently acquired by accident a 750 watt DC to AC power inverter, designed for powering AC appliances off of a car battery or other 12V power source. I have no need for such functionality. I am really interested in high voltage projects and I was wondering if there are any interesting...
  41. R

    How Can I Control AC Power with a Sensor?

    Hi Experts, I would like to make an electronic circuit to control AC power to switch on and off a light bulb based on sensor. Being new to this , i hope know what aspects i need to pay attention to when using DC to control AC? sincerely Ramone
  42. F

    Efficient Conversion of 1 V peak AC to DC

    Hey guys, I am new here and had a question. I currently have a 1 V peak (2 Vpp) AC wave coming into my system and I want to find the most efficient way to convert it into DC. A simple bridge wouldn't work for me because too much of the voltage would be dropped across the diodes. The system...
  43. K

    Calculate capacitance to adjust current in ac circuit

    Homework Statement A Purely resistive resistive 100w, 110v lamp is to be supplied by an a.c. source of 230v r.m.s at 50Hz. what value of pure capacitance could be put in series to adjust the current flow to a suitable value? Homework Equations p=iv q=cv v=ir i know a number of other...
  44. L

    Calculating AC Power for Inductive Load at 60Hz | No Average Value

    Getting powers from Ac Circuit Homework Statement Hi guys,, need help with the following question : The Attempt at a Solution OK, first things first ,, what does the question mean by saying ?? and I know that real power equal I^2 R for series & V^2/R for parallel but the problem it...
  45. N

    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...
  46. K

    Is sup AC equal to supA supC if A and C are bounded subsets of R?

    Homework Statement If A and C are subsets of R, let AC={ac: a E A, c E C}. If A and C are bounded, prove that sup AC = supA supC. Homework Equations The Attempt at a Solution I acutally think it's not always true, for example when A and C each consists of only negative numbers. If A...
  47. T

    Can a Fridge Cool a Room or Will a Canvas Roof Buffer Work?

    good / bad ideas: 1. have an extra fridge. small 170 litres. can i use it like an ac - cool the room? switch it on and leave the door ajar? 2. buy five-six 15x15 feet white canvas, put it on my roof. put 2-3 buckets of water on roof. canvas acts as a buffer between main roof and sun. water...
  48. S

    How to Express Impedance in Terms of w, R, L, and C in an LRC AC Circuit?

    How do you express impedance in terms of w(omega), R, L and C knowing the circuit diagram. I understand that for R Z=R L Z=iLw C Z=-i/wC What is the effect of having components in parallel/series, could someone please give an example of a circuit and it's impedance expression...
  49. N

    Designing an AC Ammeter: How to Find the Appropriate Resistance?

    Homework Statement I was assigned to design an ac ammeter.But i have no idea how to work on it and don't know how to find the R for the ac ammeter? Thx for the help! =] Homework Equations The Attempt at a Solution
  50. Q

    Why does OHMs law not work on AC circuits?

    can someone please explain to me physically how is it that when i have an AC source and i measure Voltage on a resistor its the same with and without the resistor and when i have a DC source and i measure Voltage again on the resistor and now there's a different reading its like ohm law...
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