Amp Definition and 377 Threads

This may be kind of odd, but this is my first post, so I'm kinda new at this. I need to calculate the output voltage of an op amp with a 2 mA current source inputting into the inverting side, and a ground connected to the inverting input. There is a 1 kiloOhm resistor going across the op amp...

Find V_o and i_o. Assume an ideal op amp. http://img236.imageshack.us/img236/2426/633bb0.jpg I tried applying KCL at v1 and v2 nodes but then got stuck because I had 2 equations with 3 unknowns. \frac{12-v_1}{4} = \frac{v_1-v_2}{8} and \frac{v_1-v_2}{8}+\frac{-10-v_2}{20}= i_o...

hey guys, i have a HW problem of a combination of a summing and difference op amp. I got the first few steps of the problem, but i don't know how to continue from where i am. I am having a hard time solving for v_+. any help is greatly appreciatd, maybe if you guys can not solve the problem for...

Op. amp tuned to "dynamic range"? You'll have to excuse me if this is a silly question, but I'm self taught in electrical engineering practices, and there are some simple things I've missed. Here is what I am trying to do(hypothetically): I have a sensor/ transducer that has a ratiometric...

hi, i am quite new to physics, so i hope you guys could tolerate with me :blushing: from what i read from internet and some chat with people, i know high volt is the result of high different potential (eg. point A got lots of electrons, so point A electrons moves to point B through a...

Hey everyone! I have a project going on with a friend...a hifi tube amp! yeehaw! Im going to start small the 60 watt range (30 per channel) and am wondering if anyone has any recommended reading for tube amp circuits, i need a book that gets right down into the dirt of tubes so that i can...

Hey guys, I'd like to build a 400W powered amplifier for small signal input from a microphone source to amplify vocals out of PA speakers. I have found the following schematic and I have two questions for whomever is willing to help: 1) Is this circuit adequate for the application? 2)...

Ok, I just want to see if this would work (but never tried it). Given a standard (though not ideal, let it be real world) op-amp, it has 5 main inputs -- I+, I-, O, V+, V-. If no loops were formed, and V+ was connected to I+ and V- was connected to I-, would the output O always be the...

help! with building a circuit. i need a gain of 300 (not exact, but somewhere around there, 200-500) for a small signal (typ. 0.1mV to 5mV) AC input with a bandwidth from 0.5Hz to 120Hz. I need it low-noise, with high precision and reliability... has anyone got a reference for any sort of help...

Hey, I think I need a little help understanding node voltage analysis with ideal op amps. For the circuit I've attached, at node D, I wrote the equation ((1/1000) + (1/1000))Vd - (1/50000)Vc - (1/1000)Ve = 0 However my prof's equation for node D is: ((1/1000) + (1/1000))Vd - (1/1000)Ve = 0...

Hi all :) I need some help with the concept of parasitic capacitance. I'm currently doing some analysis on a basic tuned transistor circuit. I know the LCR portion of the circuit is there to remove parasitic capacitance. The only problem I'm having is I don't exactly know what parasitic...

What is the difference between a current source using an op amp and one using a single transistor? Why would you use one over the other, etc? Thanks!

Please refer to file attached. I'm trying to understand how to find the gain for the JFET differential amplifier circuit, My guess is that vd2 is gm*RD. rd=infinity in this case. How do you find V1?

Question: A particle undergoing simple harmonic motion has a velocity v1 when the displacement is x1 and a velocity v2 when the displacement is x2. Find the angular frequency and the amplitutde of the motion in terms of the given quantities. The answers given in the back of the book are...

gain of the circuit is -50 V/V, open loop gain is 200 V/V. There are three resistors in the circuit. The standard R2 and R2 and there is an R3 resistor. Vo is across R3. It is connected to the output of the output going to ground. I need to find a value for R1 to make the gains works. The value...

Hi can anyone explain to me how you can drive a transistor to function as a switch?what calculations i have to make in order to decide the type of transistor that i need and the kind of resistors that i need. also i have a voltage of maximum 80 mv.i want to enlarge it in order to drive the...

Hi, I have a problem I am trying to work out on simple Op Amps gain, and I am having trouble trying to prove what the gain is. I know what the gain is supposed to be (see below), but I am stumped as to how to actually go about proving it. When I try to setup the Kirchoff node equations I get...

Hi, I've got a Hartke 3500 bass amp and the fan's broken. I need it fixed by Tuesday but I haven't got any money and the gaurruntee's expired :cry: I'm thinking a fan shouldn't be too hard to fix myself. Is this incredibly ill-advised? I know virtually nothing about how to fix stuff but I'm...

This thread is a continuation of my previous thread, except this one is primarily focusing on the contruction of an amp hour meter and programming it, rather than the gathering of parts for it. (since the parts have just arrived, very slow mail order) I am getting very confused when looking...

I have to solve an op amp circuit for a lab I'm doing but the circuit they have given me looks confusing (it's on page 46, http://filebox.vt.edu/users/oshekari/Manual_Student.pdf). Why does the 4.7k ohm resistor have an arrow pointing to the middle of the 100 ohm resistor? I know the 100ohm is a...

Could someone explain to me how solar flares occur? How do high incidence of solar flares on the sun's surface affect the Earth? I know tele-communications are affected during a solar storm. What are the possible consequences if the frequency of such solar winds are high? Also, any useful...

Hello, the other day I got an hour meter to help me keep track of the amp hours I have put into my circuit, but I am not too sure how to hook it up. it came with a page of instructions giving a few diagrams on how to connect it, the only 2 that made sense for my application of it was to either...

I figure electric guitar playing physics people might know how to answer this. Can speaker rounding be achieved at lower volume levels, without going to a low power amp? I have a 60 watt combo with one 12" speaker rated at 70 watts. It can get pretty loud when I try to get that nice...

I'm using this 25W power amp: http://www.st.com/stonline/books/ascii/docs/1478.htm And I'm wondering if I can use a generic thermal pad which I have laying around or if I need to use some other product.

Hi. I've always seen inverting amplifiers with the input going to the negative terminal of the op amp, and noninverting amplifiers with the input going to the positive terminal. However I don't see any reason why the inverting amplifier couldn't be used exactly the same way with the input going...

How long will a device drawing 8 mA last on a 12 v bat that has a 25mAh? 25/8 = 3.125 hours?

how many amp/hour can a small 1.5v produce? If u link 6 together to form a 9v, would the amp/hour change or only the voltage?