Voltage Definition and 1000 Threads

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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?

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...

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...

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...

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?

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...

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.

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...

Homework Statement Homework Equations The Attempt at a Solution

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??

[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...

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!

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?

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

What is the heat/cold ratio in thermoelectric modules to generate a specific voltage pls? old Bozo

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

Hello again guys. I've been reviewing stuff from electromagnetism and I just recently read about voltage. I know it is a difference of potential, electric potential more precisely. Electric potential is just a property of electric fields and it is measured in Joules per Coulomb. 1 Joule per...