Voltage Definition and 1000 Threads
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Determine: The r.m.s. ripple voltage
An aircraft electrical system operates at 115 volts at 400 hertz. It is to supply an average d.c. voltage of 28 volts and an average current of 20 A at a ripple factor of 0.005. Determine: The r.m.s. ripple voltage Here is my attempt. Vc= Vs-2Vd =28-2(0.7) = 26.6 Volts Vr= (1/2 x fs x C...- ifan davies
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- Ripple Voltage
- Replies: 26
- Forum: Engineering and Comp Sci Homework Help
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Can a 12V DC Source Efficiently Charge a 16.9V Lithium Ion Battery Pack?
Hi, I have built a large, lithium ion battery bank, so that I may power some of my projects from battery. The bank is 10,000 milliamp hours at 16.9 volts, and was wondering the following. Can I charge my 16.9 volt battery pack with a 12 volt dc source? would It decrease the efficiency? Would...- Puglife
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- Charging Ion Lithium Lithium ion Voltage
- Replies: 6
- Forum: Electrical Engineering
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How do Capacitors and Inductors Add/Remove VARS in AC?
To my understanding, capacitors cause the current to lead the voltage which adds VARS to the circuit and inductors cause the current to lag behind the voltage which removes VARS (in AC circuits). Also, it is my understanding that VARS increase voltage. I work for one of the largest utilities...- scrubrug
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- Ac Alternating current Capacitor Capacitors Inductor Inductors Reactance Voltage
- Replies: 4
- Forum: Electrical Engineering
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Thevenin Equiv with just Capacitors
Homework Statement imgur link: http://i.imgur.com/TWB5rRu.png Homework EquationsThe Attempt at a Solution I can find the equivalent capacitance, 10F, but I'm not really sure how to find the equiv. Thev. voltage. I figured that with the voltage source present, half the voltage will be lost...- kostoglotov
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- Capacitance Capacitors Thevenin Thevenin equivalent Voltage
- Replies: 1
- Forum: Engineering and Comp Sci Homework Help
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Understanding the Integration of i(t) to Find V(t) on a Capacitor
Homework Statement imgur link: http://i.imgur.com/zGhum8Q.png The answer given in the back of the text is imgur link: http://i.imgur.com/hAprWPV.png Homework Equations v(t) = \frac{1}{C_{eq}}\int i_s dt The Attempt at a Solution I get the last piece of the piece-wise v(t) to be...- kostoglotov
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- capacitor current integration voltage
- Replies: 1
- Forum: Engineering and Comp Sci Homework Help
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Variable Voltage Transformer for Wind Turbine Battery Charging?
We are trying to build a wind turbine which will charge a battery. Since wind speed varies (which affects the generated current and voltage), we were going to integrate a transformer in. My question is does such a transfomer even exist where the input voltage varies while the output voltage is...- ual8658
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- Transformer Variable Voltage
- Replies: 7
- Forum: Electrical Engineering
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Can you measure voltage of AA batteries while they operate?
I'm wanting to know if I can and if so how to measure the voltage of two AA batteries whilst they are in a device with the device turned on. This device is a vibrating toothbrush so if anyone could help with an answer, it would help teremendously with my science project as I am testing the...- stephencockmon
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- Batteries Measure Voltage
- Replies: 26
- Forum: Electrical Engineering
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How does increased conductivity affect voltage?
If I have a certain circuit set up with a voltage V, then how does increased conductivity in the wire affect the voltage, or does it? I know that increased conductivity affects current, but if Ohm's law is to be true , voltage must increase or resistance must decrease. So which is it? Is voltage...- Mr Davis 97
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- Conductivity Ohm's law Voltage
- Replies: 7
- Forum: Electromagnetism
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How Do Relative Voltages Affect Tube Operation in Amplifiers?
I have a question about relative voltages and operating points of components, in this case tubes. Are these two functionally the same? For a while now I never could understand how the bottom triode of the WCF in an amp I bought was biased at -100v on the grid and 0 volt on the plate which...- coinmaster
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- Relative Voltage
- Replies: 13
- Forum: Electrical Engineering
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Engineering Basic circuit operation of voltage regulator
Homework Statement Homework EquationsThe Attempt at a Solution I need to know if my understanding of this circuit is correct in terms of R1, R2, Q1, Q2. R1 is a sensing resistor and when Q1 senses a voltage drop at its base, it switches on and passes current around the regulator. I think...- CNC101
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- Circuit Regulator Voltage Voltage regulator
- Replies: 6
- Forum: Engineering and Comp Sci Homework Help
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Three-Phase Delta Network: Not all Voltage Sources are 120V?
Using the Delta Netowrk from this image: http://www.belden.com/images/B23_WyevsDelta.jpg Between Y-X, there should be 120V. Between Y-Z, there should be 120V. Between X-Z, there should be 120V. But wait! If we assign values to make the above statements true... Call X = 0V, and Y = 120V, so...- yosimba2000
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- Delta Network Sources Three-phase Voltage
- Replies: 2
- Forum: Electrical Engineering
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Measuring Voltage across Resistor in Series RLC Circuit
I was experimenting with resonant frequency of a series RLC circuit: 5V AC source 10 ohms resistor 100microF capacitor 46mH inductor Resonant frequency is calculated to be around 74.2Hz. So I set the AC source to resonant frequency 74.2Hz and measured the voltage across the 10 ohms resistor...- SataSata
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- Circuit Measuring Resistor Rlc Rlc circuit Series Voltage
- Replies: 7
- Forum: Electrical Engineering
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Engineering Calculating voltage across resistors/capacitors in a circuit
Homework Statement Calculate the voltage across each resistor and capacitor in the circuit. Homework EquationsThe Attempt at a Solution As shown in the pictures, I have calculated the combined impedance of all the resistors and capacitors in the circuit. I then calculated the supply current...- nothing909
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- Circuit Voltage
- Replies: 4
- Forum: Engineering and Comp Sci Homework Help
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How Do Charges and Voltages Distribute in a Circuit with Multiple Capacitors?
Homework Statement A potential difference of V = 38.0 V is applied across a circuit with capacitances C1 = 4F, C2 = 5F, and C3= 2F, as shown in the figure. What is the magnitude and sign of q3l, the charge on the left plate of C3 (marked by point A)? What is the electric potential difference...- vizakenjack
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- Capacitors Circuit Circuits Rc circuit Voltage
- Replies: 16
- Forum: Introductory Physics Homework Help
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The sign of the current and voltage
I was doing the following problem: And I was asked to find Iy. I found Iy to be 2.64 using KCL. However, the right answer was negative 2.64. Is it negative only because there is a dependant voltage source with "+ -" ? And why must it be negative? Does "-" in the final answer play a...- 525arneh
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- Circuits Current Kirchoff's current law Nodal analysis Sign Voltage
- Replies: 3
- Forum: Engineering and Comp Sci Homework Help
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High voltage charge & same polarity on two concentric rings
I have a charged ring with a high voltage potential. As I see it the charges repel from each other and so position themselves around the outside of the ring. I want to push the charge to the inside surface of the ring and so I envisioned a 2nd ring positioned concentrically just outside this...- BernieM
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- Charge High voltage Polarity Rings Voltage
- Replies: 2
- Forum: Electromagnetism
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How to determine the breakdown voltage of a diode?
Homework Statement The question is posted below. Homework EquationsThe Attempt at a Solution I don't know how to solve this question.Does the breakdown voltage of a diode depends on the voltage source near the diode?For example,breakdown voltage of D1 in (a) is 30V? Also, I don't know how to...- haha1234
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- Diode Voltage
- Replies: 6
- Forum: Engineering and Comp Sci Homework Help
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Voltage drop across voltage divider
Homework Statement A voltage divider with two resistors R1 and R2 is given. The output is connected to a transistor so VB is always equal to the base emitter voltage=0.7v. Homework Equations How can i explain physicaly (wath happens to the electron flow and such) why when R1 is verry high, VB...- Frankrules
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- Drop Voltage Voltage divider Voltage drop
- Replies: 8
- Forum: Introductory Physics Homework Help
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Find an expression for the capacitor voltage
Homework Statement [/B] An uncharged parallel-plate capacitor with spacing d is horizontal. A small bead with mass m and positive charge q is shot straight up from the bottom plate with speed v_0. It reaches maximum height y_max before falling back. Then the capacitor is charged with the bottom...- neilson18
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- Capacitor Expression Voltage
- Replies: 1
- Forum: Introductory Physics Homework Help
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Electrolytic capacitor voltage headroom
Hi , I'm in need for some 10+ caps for my smps secondary side smoothing. the thing is electrolytics are not cheap , so I need about 1000uF a piece but there is a big difference between whether it's 200v rated or 100v rated. the voltage across the each cap would be about 92v DC , I wonder would a...- Salvador
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- Capacitor Voltage
- Replies: 8
- Forum: Electrical Engineering
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Why does Piezoelectric output voltage dropped when load is added?
Hi, im doing a piezoelectric energy harvesting project with a standard harvestings circuit consisting of a full bridge rectifier, smoothing capacitor and a resistive load. I managed to get around 28V after rectification without connecting to a smoothing capacitor and load, but when i added a...- grasscut
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- Load Output Piezoelectric Voltage
- Replies: 12
- Forum: Electrical Engineering
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RL circuits: Find the voltage through the resistors
Homework Statement Find the voltage through the resistors. Homework Equations V=IR P=IVThe Attempt at a Solution Am I doing these correctly? Can I find the voltage across the inductor the way I did it?- Marcin H
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- Circuits Resistors Voltage
- Replies: 9
- Forum: Introductory Physics Homework Help
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Voltage Difference Along a Path
Homework Statement Given the electric field E = (2x−y2)ax + (3z−2xy)ay + 3yaz, and the piecewise linear path joining the points A(−2,1,−1), P(2,1,−1), Q(2,3,−1) and B(2,3,1), find −∫E⋅dl from A to P − ∫E⋅dl from P to Q − ∫E⋅dl from Q to B along the straight line segments. Homework Equations...- Jake 7174
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- Difference Path Voltage
- Replies: 5
- Forum: Introductory Physics Homework Help
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High voltage voltage controlled linear variable resistor
I have some high voltage (300v+) analog circuits that I want to control digitally which requires the use of a voltage controlled linear resistor that can withstand high voltages. I don't expect the current levels to be that high. I originally settled on LDR optocouplers but it turns out they...- coinmaster
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- High voltage Linear Resistor Variable Voltage
- Replies: 2
- Forum: Electrical Engineering
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Adjust supply voltage based on divider resistance
Hello, I'm working on a project and I need some assistance. I need to adjust the negative supply voltage to an integrator opamp that I use for DC offset control based upon the resistance in a voltage divider elsewhere in the design. R12 is the trimmer resistor to adjust the CVS circuit and V5...- coinmaster
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- Resistance Supply Voltage
- Replies: 13
- Forum: Electrical Engineering
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Can You Help Me Achieve a 5x DC Gain for Opamp Output Voltage?
Hello, I need an opamp that can output +/- 150v without paying $500 for a high voltage opamp. I need a workaround solution, I'm thinking of a 5x DC gain of the opamp output voltage but I am totally clueless on how to achieve this. Any ideas?- coinmaster
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- Amplifier High voltage Opamp Output Servo Voltage
- Replies: 31
- Forum: Electrical Engineering
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Solving Hall Voltage Problem Homework Statement
Homework Statement [See the figure attached] a) Find the relation between velocity of electron v and current I. b) Because of the magnetic force on the electron they move at the edge of conductor as shown in the figure and create a electrostatic force that oppomagnetostatic force. Find the...- PhyBoy
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- Electricity Physics Voltage
- Replies: 3
- Forum: Introductory Physics Homework Help
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Question based on a video (battery and voltage)
in all three cases there is no battery or voltage source,right?Because I can't see any battery.But there is voltage ,then without battery how is potential difference created?I think potential difference is generated due to charged capacitors not by battery or any other voltage source.- gracy
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- Video Voltage
- Replies: 50
- Forum: Electromagnetism
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Equivalent Capacitance and Voltage Across
Homework Statement Homework Equations Series: 1/Ceq=1/C1+1/C2 Parallel: Ceq =C1+C2 The Attempt at a Solution So to find the equivalent resistance do I short (put a wire through the open terminals) the circuit and start adding up the capacitors? Once I do that do I just create a new circuit...- Marcin H
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- Capacitance Equivalent Voltage
- Replies: 19
- Forum: Introductory Physics Homework Help
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How to Derive the Voltage Gain Transfer Function?
Homework Statement Homework Equations The Attempt at a Solution- suv79
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- Function Gain Transfer function Voltage
- Replies: 2
- Forum: Engineering and Comp Sci Homework Help
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What is more effective -- Current or Voltage?
I have fan that's 20 V and 14 A. I give it an input of 5V 1A. So my question is... increasing what will increase the performance of my fan more... Current or Voltage??- NARUTOSARTHAK
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- Current Fan Voltage
- Replies: 9
- Forum: Electrical Engineering
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Kirchhoff's Voltage Law Integral help
[SIZE=16px][FONT=Helvetica Neue]Consider the circuit from minute 6:57: [SIZE=16px][FONT=Helvetica Neue] So I have an electric field there everywhere in the loop and I can write integral of E*dl as being v and I end up with kirchhoff's rule. (you don't have to watch all the video to respond to...- RaduAndrei
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- Integral Law Voltage
- Replies: 6
- Forum: Electromagnetism
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Energy Calculations: P=VxIxt - Why Watts & not Joules?
The question: Calculate the energy used by the lamp in 6 hours of use. The answer: P=V.I.t P= 240v X 0.2A X 6hrs X 3600s P= 1036800W!? I thought energy was Joules? Why has the answer been given in watts? Please help!- GSK
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- amps current energy power voltage
- Replies: 5
- Forum: Introductory Physics Homework Help
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Node Voltage Method: Find Voltage Across 6A Current Source
Homework Statement Find the voltage, V, across the 6A current source Homework Equations V=IR Node Voltage Method The Attempt at a Solution Did I set this up correctly to find my voltage?- Marcin H
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- Method Node voltage Voltage
- Replies: 15
- Forum: Introductory Physics Homework Help
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How did they integrate the charge for Voltage question
I have a question on finding potential for a disc of charge when it comes to the simple integration how does the integral of R'dR'/etc have the R'dR' just disappear? i thought it would then be R^2/2 I am obviously missing something here- kiwibird4
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- Charge Integrate Voltage
- Replies: 5
- Forum: Introductory Physics Homework Help
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Thermoelectric Modules: Heat/Cold Ratio for Voltage
What is the heat/cold ratio in thermoelectric modules to generate a specific voltage pls? old Bozo- old Bozo
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- Modules Ratio Thermoelectric Voltage
- Replies: 2
- Forum: Electrical Engineering
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Finding Voltage graph from current graph of capacitor
Homework Statement I am given the current flowing through a 2 micro-farad capacitor in the form of a graph, and I need to create a voltage graph from this. Homework Equations I = C dv/dt Q = VC The Attempt at a Solution The current graph is basic with a constant 4 mA from 0 to 4 microseconds...- david12445
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- Capacitor Circuit Current Graph Voltage
- Replies: 8
- Forum: Introductory Physics Homework Help
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Find voltages across resistors using voltage division
Homework Statement 7a from picture Homework Equations V=IR Voltage division The Attempt at a Solution I am not sure how to apply voltage division here. It is a new concept for me and I'm not really sure how to apply it here. voltage division can only be used in series, but these resistors...- Marcin H
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- Division Resistors Voltage
- Replies: 32
- Forum: Introductory Physics Homework Help
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Piezoelectric strain rate and frequency of applied voltage
If one were to apply, for example, 60 Hz AC to a piezoelectric material, would the strain rate be 60 Hz? I am not entirely sure if I am using "strain rate" in its proper sense; I use it merely to describe what I imagine would be the rate at which the material expands and contracts while exposed...- gm3
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- Applied Frequency Piezoelectric Rate Strain Strain rate Voltage
- Replies: 2
- Forum: Electromagnetism
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What Is the Maximum Power on an Impedance Z?
Homework Statement Find the maximum power on a impedance Z. Homework EquationsThe Attempt at a Solution I got as Thevenin impedance Zt=4+j4 and Ut= 32 V, but since my solution for power is wrong, something is wrong with either impedance or voltage (or both). If point A is above Z, and point B...- crom1
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- Impedance Thevenin Voltage
- Replies: 7
- Forum: Introductory Physics Homework Help
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Charging Super Capacitor w/Buck Converter: Max Voltage Draw?
If I am charging a super capacitor with buck converter, that is a 1 amp, 1-18 volt output, and the capacitor is rated for 2.5 volts, how do I stop the buck converter from feeding it more than 2.5 volts? When I attach the capacitor to my digital power supply, it starts charging, and the voltage...- Puglife
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- Buck converter Capacitor Supercapacitor Voltage
- Replies: 5
- Forum: Electrical Engineering
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What Diode Has a Low Turn-On Voltage and Through-Hole Termination?
Hi. I'm wondering if anyone knows the model number of a diode, which has a low forward turn on voltage, and has through-hole termination. I am aware of the BAT54 Schottky diode series. The turn on voltage is as low as ##0.2 V## for some models, but the problem is they are surface mount...- STEMucator
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- Diodes Voltage
- Replies: 5
- Forum: Electrical Engineering
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Ratio of effective and average voltage
Homework Statement See the diagram. Find $$\frac{U_{ef}}{U_{avg}}$$ . Homework Equations [/B] $$ U_{ef}=\frac{U_m}{\sqrt3} , U_{avg} = \frac{U_m}{2} $$ The Attempt at a Solution This one should be easy.I know that official solution probably divided $$\frac{2}{\sqrt3} \approx 1.154$$ (which...- crom1
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- Average Ratio Voltage
- Replies: 1
- Forum: Introductory Physics Homework Help
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Voltage drop and transformer improvement
Homework Statement Power station produces AC power at 2.5Mw, I = 100A. Transferred along 100km line with a resistance of 50 ohms to a factory. Calculate power lost and % efficiency Homework Equations P=VI P = I2R The Attempt at a Solution Initial power at the station is 2.5x106 . Using I2R...- AstroJMT42
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- Drop Transformer Voltage Voltage drop
- Replies: 5
- Forum: Introductory Physics Homework Help
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Voltage vs. Current Sources: Understanding the Differences
Homework Statement Check picture Homework Equations V=IR The Attempt at a Solution I thought I had this right, but then I started thinking about it and I'm not sure anymore. My thought was since the voltage was changing and the current was constant, that the source was a voltage source. I...- Marcin H
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- Current Current source Source Voltage
- Replies: 2
- Forum: Introductory Physics Homework Help
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Odd voltage reading from digital volt meter
I have a three phase alternator and I used a digital voltage meter across the output terminal and the reading went from OL to 4000 volts to 3000 volts and quickly decreased to zero volts, then went through the range again starting from OL. It continued to do this, I thought the meter could have...- Idea04
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- Digital Meter Reading Volt Voltage
- Replies: 15
- Forum: Electrical Engineering
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How Do You Sum Two DC Voltages in a Laser Spectroscopy Circuit?
Hi all, Building a frequency offset locking circuit for laser spectroscopy. First electronics project so been hitting a steep learning curve. Long story short, I have two branches in this circuit that take a AC signal run it through a diode and low pass filter to measure the envelope and output...- Tom_M
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- Dc Signals Voltage
- Replies: 3
- Forum: Electrical Engineering
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Need help conceptualizing constant voltage in hollow sphere
I realize that this is probably really basic, but I can't quite conceptualize a hollow metal sphere having constant voltage and zero electric field inside of it. I've searched around on the Internet, and I've seen stuff about Gauss' Law, but even after reading into that a little bit I can't make...- cmkluza
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- Constant Sphere Voltage
- Replies: 1
- Forum: Electromagnetism
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Two voltage sources and two loads, how to approach this one
Homework Statement imgur link: http://i.imgur.com/G9RKEH1.png Homework EquationsThe Attempt at a Solution [/B] Should I just consider that A and B are parallel with each voltage source respectively and so therefore that's the voltage drop that they experience individually? The ground...- kostoglotov
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- Approach Parallel Sources Voltage
- Replies: 2
- Forum: Introductory Physics Homework Help
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Voltage at load of distribution network
Please bare with me, this is my first post here (although I've read a lot on here over the past few months) Hopefully I've used the correct formatting etc. I've got to a sticking point on the final point of the question below (2iii) I'm pretty happy with my answers to 2i and 2ii so I've not...- ClimberTom
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- Distribution Load Network Voltage
- Replies: 1
- Forum: Engineering and Comp Sci Homework Help