Charging Definition and 407 Threads

I have a very small solar cell that outputs 4 volts (open circuit) and 50 μA (short circuit). I'm trying to charge a 0.33 F capacitor that is rated for 5 volts. I'm looking to understand the charging relationship. 1. What equations govern the charging of this capacitor? I'm already aware of...

A simple type of blinking light circuit can be constructed using a neon lamp. The circuit shown here has a 4.0 μF capacitor in parallel with a neon lamp. When the voltage is low in the RC portion of the circuit, the lamp does not conduct electricity. Therefore, it is effectively not there from...

It's a routine to calculate the magnetic field between circular capacitor plates by the Ampere-Maxwell law, and it can be shown that the magnetic field increases linearly with the distance from the center of the capacitor plates, with direction parallel to the plates. But what if the radius of...

Why during charging a battery the terminal Potential Difference becomes greater than the EMF?

Hi, anyone could explain what exact the "shunt susceptance" and "shunt conductance" are? and what's the difference between shunt susceptance and line charging susceptance? In power system analysis, shunt susceptance and shunt conductance are bus elements. Whereas the line charging...

Okay so, PF, here is my situation! I have my cell phone and my digital camera and they both came with those wall chargers where you plug in a USB cable into the actual wall plug. This allows you to use the same cable to charge off a wall or a computer. Now, I was wondering if I can use the plugs...

Dear Experts As a rechargeable battery , say a li-po battery, is being charged to near charging voltage, there is less potential difference which in this sense means it takes longer and longer to reach remaining few 0.x volts. Could you be so kind as to explain a bit how a typical charger...

No Idea how to work this out! -- Charging and discharging an iPod Homework Statement It takes about 5 hours for a fully charged ipod nano to run out of power when its screen is left on and all other functions are switched off. Subsequently, it takes about 90 minutes to recharge the ipod...

Hi I was just on vacation and forgot my camera's battery charger. I thought a lot about building some sort of homemade charger, but just didn't dare try. Luckily it ran out on the very last day, but I'd like to know if it would've worked. Basically, the camera has a 7.4V Li-ion battery, which...

If I am trying to minimize triboelectric charging. What two substances when rubbed together would produce minimal field lines and minimal charging?

Hi there, I'm just wondering if anybody would know of a way of determining the probability of an event. I trying to figure out how I could calculate the probability of a charging station for an electric car being available when a person arrives at their destination. I have the...

I'm having trouble understanding where the charging time in a capacitor actually comes from. Is it possible to derive the \tau of a capacitive circuit from the drift velocity of the electrons? Are charges literally moving from the conductors onto the metal plates of the capacitor?

Dear Experts We know that a capacitor is charged such that the voltage increases exponentially and tapers off as it reaches its max voltage. I have a lithium ion bettery 4.2V. If my supply voltage is 4.2v, is it not true that : 1. As the battery is being charged nearer to 4.2v, the...

Homework Statement The Problem is as follows :- https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-snc6/250882_2277870163529_994629362_n.jpg In the figure shown initially the switch is open for a long time. Now the switch is closed at t = 0. Find the charge on the rightmost...

Homework Statement The question says A capacitor of capacitance C is given a charge Q . at time t = 0 This capacitor is then connected to another identical capacitor which was initially uncharged through a resistance R . Find the charge on the second capacitor as a function of time . ( I am...

Homework Statement When charging a capacitor with NO resistor in the circuit, the p.d of the capacitor IMMIDIATELY reaches a maximum... Homework Equations The Attempt at a Solution ...is the following reasoning correct: As stated by Kirchoff's Law, the sum of the potential differences...

Hi, I have simple question: In small OFF GRID wind turbine systems, it is worth to continuously charge & discharge 12V Lead Acid Batteries? this means that we want that our loads (lights, Fans e.t.c) are 24hours taking power from wind turbine & batteries will continuously charge &...

Homework Statement Can somebody explain how it is possible to charge a capacitor using ac voltage? The way I see it is the capacitor wouldn't have time to charge as the voltage is constantly switching. In the case of 60Hz - 120 times a second. I seen a schematic of a tesla coil where the...

Can somebody explain how it is possible to charge a capacitor using ac voltage? The way I see it is the capacitor wouldn't have time to charge as the voltage is constantly switching. In the case of 60Hz - 120 times a second. I have attached a schematic of a tesla coil which is how I come to...

http://www.youtube.com/watch?v=o0hXYfvnND0 What would happen if the ground was kept in place and the positively charged rod was constantly moved to and away from the electroscope? Would we not have ac current between the Earth and the electroscope? Replace The electroscope with a capacitor...

Homework Statement So I came by this question yesterday which was in Solved examples part of my Textbook . I looked at the Solution and was not able to figure out how ? The Question says . A 5uF capacitor is first charged by applying a Potential Difference of 24 V . a different...

Hey Everyone, I am working on a project that uses induction to charge a widget by placing it within an EMF… just like how an electric toothbrush charges. This is for a device that will be used in the power industry, so we’re dealing with exposed, high voltage lines. Do you know of an...

hi i need an equation which can describe the charging time of two parallel capacitors one of them is %50 charged and if i have a capacitor which is always charged from 50% to 100% and never fully discharged will it have a different impedance than the fully charged/discharged capacitor?

Can i charge 12V 15Ah sealed lead acid battery by giving 60V 4A to it's terminals ?

The energy stored on a charged capacitor is 0.5*Q*V or 0.5*C*V2 BUT what is the electrical work done by the supply as it transfers the charge to the capacitor? I have heard two answers: W=QV and W=0.5*QV the first answer implies, i think, that energy is required to move charges against...

I have a battery. I can go get a screwdriver from the garage and open it to see the specs on it, but was for an electric bike. I don't have the AC adapter charger any more. Can I charge it with a universal AC adapter I have, just wired together? The AC adapter has two holes in the tip, and I...

hello, pozdrav my question is about Valve Regulated Lead Acid battery. may i charge it only with "float" voltage (cca 2,25 Vpc) or do i have to "boost" it (2,4 Vpc) sometimes? if my battery gets discharged to 20% can i recharge it only with "float" voltage? i have capacity cca 150Ah...

Homework Statement Suppose we have a circuit represented, which is used for charging an accumulator from a.d.c supply of e.m.f, E1 and internal resistance, r1. If the e.m.f of the accumulator is E2 with an internal resistance of r2, then the equation for the charging current is what? In...

Is it safe to charge a supercapacitor from a source with more than it's rated voltage, provided that the voltage across the cap never exceeds the rating? For example, the cap is rated at 2.7V, and i charge it from two AA batteries giving just over 3.2V in open circuit. Once the battery...

Homework Statement why is the current-time graph for a charging AND discharging capacitor the same? Homework Equations The Attempt at a Solution Q=It so for a discharging capacitor as time goes on the charge stored decreases so current decreases BUT for a charging capacitor...

Homework Statement You need to modify a simple charging RC circuit (power supply, resistor, and capacitor in series) to maintain the same maximum current but lower the the time constant and make it charge faster. Which of the following will accomplish it? A) Same R, lower C. B) Same R...

My son pulled the wires off of the charging plug for his motorcycle (mini-bike). I can use a Fluke to determine what side is positive comming from the charger, and trace the positive side from the battery to the charging socket. My question is when charging do I connect the positive side of...

A 38 μF capacitor is charged to an unknown potential V0 and then connected across an initially uncharged 13 μF capacitor. If the final potential difference across the 38 μF capacitor is 37 V, determine V0. Answer in units of VQ=C∆V

Dear Experts There are solar charging devices in the market for electronic devices. These contain some electronics which I suppose is to regulate the power or as controller. Lets say I have a 6 volts device and I have a solar panel rated at 6v. If without any electronic controller...

What really happens when charging a capacitor?? Do the charges move from plate to plate or do the charges in the wire only move towards the plates----> "During charging electrons flow from the negative terminal of the power supply to one plate of the capacitor and from the other plate to the...

While analyzing the quarter project of my physics class, there was a question that I counld't answer. The question of the experiment is: How do the charging times of different capacitors vary with capacitance? Objectives • Collect and organize data on the rate of charge of different...

Hello Forum, I have a MacPro Apple computer. I just got a new power adapter rated 85 W. Does it mean that the computer is always drawing 85 W of power does is the power delivered depend on how many programs are open, etc...? thanks fisico30

Hello: I have a basic query, regarding the charging and usage of battery. When I charge a battery it needs some energy, say 100 watt. Does the charged battery now will provide me back 100 watt (or more or less)? My confusion is specially due to, we use invertors in most of the places to...

I need some help on the interpretation of our laboratory experiment in physics. In our lab experiment we charged and uncharged a capacitor. And here are the things we observe. 1. when one bulb was connected in a circuit across a 4.5 V potential source, the bulb turned on with a bright...

I have a Dell Inspiron 1525 and it won't charge. When I plug it in the charger, all it says is "Plugged in, not charging." I have replaced the battery but it still won't work, what is going on? Also, there is not enough power in the computer to keep going, so the charger has to be plugged in...

Hi all, I am trying to determine what is the maximum number of amps I can charge 4 batteries that are in parallel and series ( 4x12V batteries) to produce 24 volts. I have the specs on the batteries and everything but can not seem to determine how many amps they can handle when being...

Hi everyone, I'm doing a problem that involves two circular capacitor plates with radius R connected to wires running current I (as in a circuit), and need to find the magnetic field at three different regions between the two plates as a function of r, radial distance from the center of the two...

Hello! Not sure if this should go here, but it's from a physics textbook. I was reading about charge by induction and the use of an Earth to achieve this. Here's a wonderfully detailed and exquisite image that took many laborious hours to construct. The red and black Earth's are not intended...

Homework Statement You have one capacitor C1 (1uF) charged to 10V. Now the capacitor is switched to charge another capacitor C2 (0.25uF), Whats the voltage on C2? Everything's ideal. No loss caps, no wire resistance. Homework Equations The Attempt at a Solution I tried...

How do you measure the voltage of a cockcroft walton multiplier over time to observe the charging behavior? Does measuring with oscilloscopes discharge the capacitor hence you can't observe the charging or not?

Homework Statement A circuit is powered by a 10 V power supply and has a resistor of 500 ohms in series with a capacitor. After 4 seconds, the value of ln(1-(Vc/Vo)) is -2, where Vc is the voltage in the capacitor at a given time and Vo is 10 V. 1) Find the capacitance. 2) Find how long...

Homework Statement The RC circuit pictured below begins with capacitor C completely uncharged. I: What is the current at point A immediately after the switch closes? II:What is the current at point A 'at the end of the quaternary period' (I lol'd when he worded it like that) after the switch...

This isn't a homework question as such, but according to my physics book in electricity it is always the negative (electrons) charge that move. Is it possible to charge something negatively via induction? I mean the last step in the process is earthing the object, if you Earth it, do positive...

Hello this is my first post, I just joined, I hope I am posting in the correct place. I belong to some computer forums and some biker forums but not sure how these technical forums work. I am not a student but an enthusiest (spelling?). My current subject study is: In automotive charging...

I don't understand why the plate linked to the negative battery becomes negatively charged. To begin with, each plate is neutral so each contain equal amounts of positive and negative charge. When connected to the battery, the plate linked to the postitive battery terminal becomes positively...