# circuit theory

1. ### Calculations for a capacitor charging from another capacitor

Hi all, I'd appreciate help in calculating the voltages in the circuit shown. I thought it should be fairly straight forward, but it has me stumped. This is a sample-and-hold circuit for an ADC -- the switch is closed to charge the hold capacitor with the sample voltage and then opened to...
2. ### Insights A New Interpretation of Dr. Walter Lewin's Paradox - Comments

Greg Bernhardt submitted a new PF Insights post A New Interpretation of Dr. Walter Lewin's Paradox Continue reading the Original PF Insights Post.
3. ### Engineering Calculate the effective values in this 3-Phase Circuit

Homework Statement Given the known quantities $R, C, L$, $k$, and the effective values of the voltages $E_1=E_2=E_3=E$ , $w = \frac{1}{\sqrt{LC}}$ of the direct-symmetrical 3-Phase system find the expressions for the effective values of $U_{12}$, $U$ and $I$ and calculate the...
4. ### Complex Capacitor Circuit (for me)

Homework Statement 1. V for C1 2. Let's Say "C" is Resistor then C1 = R1 etc. how to get Eq Resistance for this Circuit ?[/B] Homework Equations Faraday's Law, Kirchoff Law The Attempt at a Solution [/B] for no 1 :I just want to make sure. point A is transfering negative charge to C2 and...
5. ### Resonant Frequency and Transfer Functions

Suppose I have some sort of a filter, whose transfer function is given by H(w), where w is the angular frequency of the input signal in radians per second. I want to know the maximum value of the transfer function. If I solve for the resonant frequency w0, which from my understanding is the...
6. ### V2 of two symmetrical T attenuator pads in cascade

Homework Statement http://imgur.com/qBXvrGz Above is a sketch of the circuit, a two stage symmetrical attenuator consisting of two symmetrical T attenuator pads connected in cascade, with the values that I have worked out for the resistors. The reduction is 15dB in the first stage, and 8dB in...
7. ### Engineering Laplace tranforms, transient current series CR circuit

Homework Statement A step voltage of 120v is applied to a series CR circuit. R = 20KΩ, C = 4µF 1. Deduce, using Kirchoff's voltage law and Laplace Transforms, an expression for the transient circuit current. 2. Using the equation obtained in 1. deduce the equations for the transient voltages...
8. ### Engineering Solving a linear circuit

Homework Statement In the circuit above $E_1=E_2=E_3$, $Ig_1=Ig_2=Ig_3$ and $R_1=R_2=R_3=R_4$. In the case when the switched is closed the power of the ideal generator $E_2$ equals $P_{E_2}=-30W$. Then the switch opens. Calculate the $ΔP_{E_1}$. Homework Equations 3. The Attempt...
9. ### Engineering Circuits 1 help with integration

Homework Statement http://imgur.com/a/qlQ5z Homework Equations i=i(o)+1/L integration(v0) dt formula is in the attemp at a solution. The Attempt at a Solution http://imgur.com/a/HVjl1 For the interval 2<t<infinite . I understand...
10. ### Equivalent impedance

Homework Statement Hi everyone, I'm just having a little trouble with equivalent resistance in a bridge, in the image I attached. The textbook says that the way to solve this is to put R3 and ZL2 in series, that series is in parallel to the short circuit in diagonal, and then at the end we...
11. ### Bridge two circuits

Is it possible to have one part of the circuit running with electricity then manually add in a second part of the circuit to the first part and have both running simultaneously? Is there a name for such a circuit? The voltage and current of the first part of the circuit would change because of...
12. ### Best way to improve knowledge of electronics/circuit theory?

Hi guys, I recently finished my Physics undergraduate degree, and will be starting my first job in September. My employers have asked me to improve my knowledge of electronics before I begin work. I would like to improve my ability to analyse and understand circuits, and also learn more about...
13. ### How does a current source work in Norton's Therom

Hi.i know that a ideal current source has infinite resistance and it supply's constant current to aload connected across it. The current source doesn't have the infinite resistance in series to it but in pparalle. All is well until I think of this Norton's Therom. When we transform a voltage...