Rc Definition and 632 Threads

Homework Statement A circuit consists of a Zener diode, capacitor and resistor in parallel. Voltage to be maintained across the components is 4.7V, power 5mW. Find the values for resistor and capacitor Homework Equations (Below) The Attempt at a Solution I found the resistance by...

Homework Statement Okay, I don't EXACTLY remember the problem statement or the circuit diagram, but I believe I can give enough information to do the problem. On this past quiz, I got 75/100, where there are 4 parts: 2 short answer, 1 part multiple choice, 1 part group test. I got 25 on MC...

help me on these questions please~ srry ~ i posted wrong forum

In RC circuit, what is the mathematic relationship between the time of charge or dischare and the capacitors ? time of charge or discharge andn the resistances? I know that as the capacitor or the resistance is increased, the time it take to charge is also increase as well. But I am not sure...

[SOLVED] RC Circuit Help Homework Statement What is the potential of point a with respect to point b in the circuit shown when switch S is open? Which point, a or b is at a higher potential? b.) What is the potential (after a long time) of point a with respect to ground when switch S is...

Strictly speaking, the equation q=Q_0e^{-t/RC} implies that an infinite amount of time is required to discharge a capacitor completely. Yet for practical purposes, a capacitor may be considered to be fully discharged after a finite length of time. To be specific, consider a capacitor with...

Homework Statement Given an RC circuit which has a Capacitor (C=6\times 10^{-6} F) and a resistor (R=5 \Omega) conected in series to an a.c. voltage source of the form v=V_{0} e^{j\omega t} with a V_{0}=1 Volt. Frequency f=10kHz a)What is the phase of the current with respect to the applied...

Homework Statement I can't post pictures as I do normally, so you'll have to deal with the cumbersome attachment method! It's just a simple RC circuit. Resistor on top, capacitor on right side with the sinusoidally varying voltage source on the left...

[SOLVED] Help with RC circuits Can someone explain how to find the intantaneous value of voltage in a capacitor at any specific instant in time. I am taking a course in electronics and the textbook isn't really clear on this. I have the equation: -t/T Vc=E(1-e )...

I am trying to imitate the Airhog zero gravity climber one of these http://www.gmhummer.com/forums/showthread.php?t=111 can someone please help me regarding derieving equations for the suction pressure required and regarding selection of motors for driving suction fans. the toy...

This is an experiment Ill have to write up later, unfortunately I was out for 2 weeks of lectures due to illness. This is the experiment; Find the values of capacitance C and resistance R in a series combination, given he following apparatus; 1. the unknown RC combination (both in the same...

Homework Statement The switch has been open for a vary long time, and is then at time T=0 closed. Determine the voltage V0(t) for t>0 Homework Equations voltage from a discharging capacitor is V*e^(-t/RC) Where V is the voltage stored in the capacitor, R is the resistance and C is the...

Homework Statement You see this trace on your oscilloscope for an RC circuit. The vertical scale is 5volt/square and the horizontal scale is 50ms/square. What is the time constant of the RC circuit? Homework Equations Vc(t) = Vo(e^(-t/RC) Vr(t) = -Vo * e^(-t/RC) t halftime = Tln(2) =...

I've seen the designs using the 555 timer as the base and making a 2 led IR emitter. These examples use 5v and only two leds to send the 40k signal. http://www.reconnsworld.com/ir_ultrasonic_555timer40khzir.html I would like to modify this design to run off 12v and use 8 infrared leds. I...

Homework Statement In a circuit, the switch S has been open for a long time. It is then suddenly closed. Determine the time constant (a) before the switch is closed (b) after the switch is closed. (c) let the switch be closed at t=0. Determine the current in the switch as a function of...

Why does a constant current source need to be used in a parallel RC circuit? Why does a Constant Voltage source need to be used in a Series RC circuit?

Homework Statement 1. What electric field strength is needed to create a 5.0 A current in a 2.0-mm-diameter iron wire? 2. You need to design a 1.0 A fuse that "blows" if the current exceeds 1.0 A. The fuse material in your stockroom melts at a current density of 500 A/cm^2. What diameter...

RC Circuits! A capacitor in a single-loop RC circuit is charged to 63 % of its final voltage in 1.5 s. Find (a) the time constant for the circuit and (b) the percentage of the circuit's final voltage after 3.5 s. Given that V/Vo = 63%, t = 1.5 sec , Time constant =τ Now...

The problem is in bold and my logic/answers/questions are below. Please check my logic and any help with my uncertainties would be...well, helpful. thx The switch has been in position 1 for a long time. Determine the voltage drop Vc(0) and V0(0-). Since it has been a long time the capacitor...

Homework Statement There is an RC circuit with a 6 V battery, a 100 Ohm resistor, and 2.0 microFarad capacitor. At time t = 0, the switch is closed. While this happens, an ammeter measures the current through the resistor. At t = 0.000139 s the ammeter finds that 0.030 A is flowing through...

Find v(t) at t=800ms for the circuit in Figure 1. Ans: 802mV Writing a single node equation we have \frac{v(t)-2tu(t)}{5}+0.1\frac{dv}{dt}=0. Taking the Laplace transform we have L\left\{ \frac{v(t)-2tu(t)}{5}+0.1\frac{dv}{dt}=0\right\} . tu(t)\Rightarrow\frac{1}{s^{2}}...

Does the capacitor acts as a current source and the inductor acts as the voltage source in the RC and RL circuits respectively? If so why does the capacitor not act as a voltage source and inductor not act as a current source? Thankyou

I'm working on an RC circuit lab and I can't figure out if my graph of R vs. tau is supposed to go through the origin. According to the equation tau = RC, it seems like the graph definitely should pass through the origin. However, given the definition of tau as the time constant equal to the...

Hi guys, Here's the link to a RC phase shifter -...

Why the voltage across the capacitor can be measured by connecting a CRO across both the resistor and capacitor ? actually,i have think of the phase difference and the overall resistance.Still,i can't find the answer.May I get some hints from you?

Homework Statement A capacitor is charged to 1 coulomb; the capacitance is 9.00×10-5 farads. Then a switch is closed which puts the capacitor in a closed circuit with a resistor; the resistance is 9.0x10^1 ohms. Calculate the charge on the capacitor after 4.00 milliseconds. (1 ms = 0.001 s)...

Homework Statement I'm supposed to find the voltage v0(t) for t > 0 for the following circuit: http://img516.imageshack.us/img516/5858/circuitta7.jpg Homework Equations The first part of the excercise was to find the current io(t). I did this by using the node-voltage method to find the...

I am trying to figure out how to come up with an equation to calculate the voltage across a capacitor for an RC circuit that is supplied by a chopped / full-wave rectified ac waveform shown below. The shaded portion is the actual input signal to the RC circuit. anybody have any ideas ?

Ok, if I have a Battery B, Resistors R1, R2, and Capacitor C in this circuit: (the ...'s just represent empty space, spaces were getting eaten when I previewed the post) |----------R1--------| |......| B+......| B-......C |......| |---------R2---------| is this...

Homework Statement A 1.47 micro F capacitor is charged through a 123 Ohm resistor and then discharged through the same resistor by short-circuiting the battery. While the capacitor is being charged, find the time for the charge on its plates to reach 1/e of its maximum value. Homework...

I´m trying to understand a circuit that is build like this: ----###R1###---###C###---- ###---------###----------### -----###L###---###R2###--- How am I supposed to find what frequency (not f=0) the impedance is pure resistive? What I´ve read has it something to do with the resonant...

Hi everybody! This is my first post, happy to be a part of this forum! I have a problem that may be pretty easy to solve, and a few years ago I could've myself, but at the moment I'm stuck. I enjoy fiddling with electronics during my free time, and I'd like to study the use of a capacitor to...

hey, i need some help with a project i am working on. what i am trying to do is take a full size car and turn it into a RC car. however, inorder to keep the car street legal, i need to keep all the controls operable by a person. i am using only off the shelf parts and servos that you can...

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Hello All, I'm having problem to solved the attached RC circuit. The initial conditions are: VC1(0)=V, VC2(0)=0, and the qeustion is what will be the VC2 after t1 (t1>>0)? but i always get VC2(t1)=V which is imposible. I'm solving it by using i=cdv/dt 3. The Attempt at a...

1. A 6V battery is connected to a 1F capacitor and 3 resistors (R1=1, R2=4, R3=2) R1 is is series with the battery. A junction then appears after R1, which creates 3 different paths, 2 for each remaining resistor, and another for the capacitor. After a long time, what is the magnitude of the...

hi.. i m new here.. quite recently, i hav turned my attention to radio controls. i also built one but blew it up coz of messy power supply. what i want to know is that if i buy a complete radio control kit from a hobby shop, ll i be able to assmble it myself n ll there be any manuals for...

Homework Statement http://img515.imageshack.us/img515/7671/untitledtu4.jpg The Attempt at a Solution I really don't know how to tackle this question, but here is my attempt anyhow (wrong I know! ) RC=5000*2*10^-6 RC=0.01 V=Vo*e^(-t/RC) 0.99=e^(-t/0.01) ln(0.99)=-t/0.01...

While working on an example in my Circuit Analysis textbook, I came upon the following circuit: A 9v battery is connected to a resistor R1 (this is the left loop of the circuit). It is also connected to a resistor R2 and a capacitor C1 that are in series (that is the right loop). The authors...

Hello All, I'm doing some fun at home experiments with my 1:6 scale RC car and I wanted do some camparisons with its full scale counter part. Mainly how jumping the two off a ramp (Duke's of Hazzard style). I wanted to know if you can help me with confirming some of my scaling...

I just need some help understanding some of the theory behind these.. Can anybody help explain the relevance of a time constant in an RC circuit and why the time constant increases as resistance increases? Thanks in advance:blushing:

Its been 30 years since my last Physics course so while I have the basic concepts I'm uncertain how to solve my current problem: I need to operate a pair of 12V solenoids (.5 seated amps, 4 watts each) with a periodic on/off cycle that gently ramps to full voltage (over about .5 to 1 sec) and...

Homework Statement http://img167.imageshack.us/img167/7747/picture2mg7.png Homework Equations iL(t) = current through inductor Using The Step by Step Method: Assume the solution iL(t) = K1 + K2*e^(-t/tau) where K1 = iL(infinity) and K2 = iL(0+) - iL(infinity) so, Assume the...

Hi, I have this problem to do for HW. I did what it asked for, or so I think. I think I may have made a mistake somewhere, it's telling me its not correct. Can you check it out? BTW, I have to use the step by step approach. I'm assuming my solution will be v(t) = K1 + K2 * e^(-t/RC). I then...

Hi guys, I have a lab I have to do for an introduction to 1st-order networks. Can you perhaps check my work? I'm pretty sure most of it is correct. I have attached a PDF file, so you can see my lab. Thanks guys. (it's not that long, it'll take at most 1-2min)

Hi, I am working with capacitor now and I have this question. I am applying a square wave (from 0 to 5V) on a RC circuit. At the output ( at the resistor) I get a positive and negative values? why is that ? I am suspecting the fact that the capacitor create a phase difference of -90...

So, I understand the charging of an RC circuit perfectly, but I am a tiny bit bothered by one part of the formulation of charge on a capacitor plate as a function of time for a discharging capacitor in a simple RC circuit (charged with one battery, one resistor and one capacitor all in series...

Homework Statement A resistor of 362 Ohms is connected in series with a capacitor of 50.0 µF capacitance. A sinusoidal signal of f = 11.7 Hz experiences an impedance of 452.836 Ohms. Find the phase shift between the current and voltage at f = 11.7 Hz. Homework Equations I tried using...

Homework Statement In Figure P18.50, suppose that the switch has been closed for a length of time sufficiently long enough for the capacitor to become fully charged. (R = 12.0 k, R2 = 17.0 k, R3 = 1.00 k, V = 9.70 V) The picture is under attachment a) Find the steady-state current in...

Homework Statement I was asked to desing a RC passive high pass fiilter with a cutoff of 3KhZ. Homework Equations The formula for Fc = 1/(2piRC) The Attempt at a Solution I set 3kHz = (1/(2piRC)) but am not sure what to do next. Do I pick a random cap or resistor value and...