Amplifier Definition and 544 Threads

Hi everyone, I am currently doing some experimentation with electromagnetic coils, I realize I will need a waveform amplifier for the testing using my rsr32 function generator. Could someone point me in the direction of a decently priced one?

Hi, I'm trying to understand the operation of the schematic I attach. http://imageshack.us/photo/my-images/853/abampschematic.png/ What's the point of having the input at the Q1 collector? I can understand the more common structure shown in wikipedia (...

I have two current signals from a two color Si-photodiode/PbS-photodetector. I want to measure the signal with the Stanford Research Lock-In Amplifier 830. I read in the manual that I can measure currents with the SR830. Does anyone have experience with this? Do I get better signals if I...

how can i find input and output impedance of a ce amplifier- (voltage divider )..suggest practical methods?

Homework Statement See attached file for relevant questions. I'm finding the Op-amp questions in section A very difficult. Any help with these questions would be much apprietiated. Homework Equations The Attempt at a Solution

Hi everyone, I need to find the voltage gain for the following scheme: My book says I need to calculate 'id' first, which is: id = gm.ro.vin/(Rs+RL+ro+(gm.ro.Rs)) Then with the help of vout = -RL.id you get: Av = -gm.ro.RL/(Rs+RL+ro+(gm.ro.Rs)) So I get the last part, but I really have...

I have a quick question. I can't find anywhere the answer in my textbook. What is this -Vee in attached image? And how do you equivalent that? And it says here in given parameters that -Vee=-12 V, isn't that +12 V?

hi all i have some questions about a commen emmiter bjt amplifier circuit . if i had this circuit : and i want to find the ripple of voltage in outout : i will use this equation : V_{O(p-p)}=2I_{CQ} (R_L || R_C) but why i put R_L || R_C not R_L || R_C + R_E or how i conclude that...

Hello Everyone, I have a question about how power amplifiers output their power to 3 phase motors. I am using a copley xtl power amplifier to power a 3 phase motor, i want to use a relay to interrupt that motor current but I am not sure how to size it. If the peak output of the amplifier is...

Hi everyone, I'm going to comment about something that happened to me today using Summing OpAmps. First, I simulated the attached circuit in a Project Board. It's supposed to be a Single Supply summing op amp with unity gain. The thing is it never worked. The signals didnt even appear in the...

Dear all, I measured some very nice data, but it's difficult to analyze, but I try to get out of it what I can. I have diverging resistance and did measure with standard lock-teqnique: apply 0.45V over preresistor and send current over sample and measure the two-probe resistance over the same...

Hello. I believe there's a flaw in my understanding of the operational amplifier. I'm getting a bizarre result that I'd really appreciate if anyone can help me with. :) 1. http://tinyurl.com/6e9ovvp The part I'm having problem with is Q9 (b) (iv). 2. V=IR The Attempt at a...

How to use the instrumentation amplifier? Is it a voltage follower? Can it be used for isolation?

Homework Statement I have attached the question as a photo. It contains two parts. Homework Equations The Attempt at a Solution For part A, is it simply Q=CV where C is given and Q is the elementary charge times 10^6? For B, I am not quite sure where to begin. Any...

Homework Statement Derive an expression for the gain Vout/Vin. Express your answer in the form of A+jB. Homework Equations The Attempt at a Solution If C is the capacitor in series with R1, gain = 1 + R2/[R1 + 1/(jwC)]. It says to express it in the form of A (real)+ jB (imaginary), but I'm...

Homework Statement Heres the question, I honestly don't know where to even begin :( An AC model of a cascode common-source amplifier is shown below. M1 and M2 are biased in saturation mode. The parasitic capacitors in the transistors are included. Determine the poles in frequency response...

Problem: http://img443.imageshack.us/img443/2926/capturelgw.jpg I need help getting this started. Does anyone understand that R1, R2, R5, R6-11 are 100k, but then what's that -1.0 M doing underneath? Also I think that R11 - 20k is a typo to mean R12 as the potentiometer. Id appreciate some...

Need some help guys https://www.physicsforums.com/attachment.php?attachmentid=32237&d=1297816285 I began to analyze it and I got to this: OA2 is a non inverting amplifer OA1 is a voltage follower thus: V1(1+ (R1/R2) is the input for R3 into the final op-amp OA3 which is an...

Hi, I have a quick question regarding Operational Amplifier's. I understand in an ideal Op-Amp the current through the + and - input terminals should be zero. What is the point of the Op-Amp if no current goes through the inputs? How does it work? thanks

Homework Statement given input as 100mV peak and expected output to be 10Vpeakto peak...i am having trouble on how to find the different values , like resistors , capacitors ...i am planning to use fixed bias circuit (common emitter configuration) and my transistor gives a value of hfe=...

Hi guys, can anyone tell me the reason why we set Vi=0 (short circuit the input side) when we want to find the output impedance Zo but we don't do the same by setting Vo=0 when we find the input impedance Zi? and why do we let Io=0 (open circuit the output side) to find the gain Av? thank you

hi... after amplification of a signal through an amplifier, the amplified signal is 180 degrees out of phase with input..why?? thanks..

Can anyone please give me the design of a high power opamp based amplifier, Vcc(100-200V, single power supply), Output current(tens of amperes)

How to calculate the efficiency of an amplifier e.g. op-amp? Been thinking about that, and have no answer. It should not be Vout / Vin ?

Is op amp or any amplifier circuit/device a over-unity efficient device? The above question has been stuck in my mind, and I can't figure it out, as Vout is greater than Vin which Pin>Pout. So is it? I heard a lot about free energy and aether, thus come to this question.

Although this question may seem too simple, I still want to ask it on the forum because I’m really confused…… Here are the easiest amplifiers circuits for DC and AC currents, and what’s shown in the oscilloscope I’ve got in Multisim (corresponding), I want to know why ic/ib is negative in the...

Hi, we are designing a new radon detector which filled with two parts as CSA&SA(charge sesitive and shaping amplifier) in the total system. I attached a Circuit consisting of those two parts and i need to know the function JFET in CSA. In the given circuit i mentioned one arrow at the...

greetings, i wonder if anyone could tell me that how and why there is 180 phase shift in single stage transistor amplifier circuit?

Why does the small signal voltage gain collapse as we increase the AC input voltage? Voltage gain = Av = (output voltage) / (input voltage). Both small signal (AC). When you draw the small signal circuit using T-Model, you can find that Av= (gm * Rd) / (1 + gm Rs) gm being the the...

Hi Please remember that I'm not a physics or science student. Just trying to learn things. So, please be simple with your replies. Thanks. I found this amplifier circuit on this webpage: http://www.circuit-lab.com/2009/12/30-watt-audio-power-amplifier-schematic.html Now I have connected the...

Hello... Am undergraduate EE, and am working on my final year project which is the development of prosthetic arm which will work on signal from muscles taken from surface myoelectric sensors. First of all i will explain about circuits i want to build, and i wish i will have comments...

How to build this amplifier ? Need what component!

Long story short, I'm trying to "easily" increase the bandwidth of a transimpedance amplifier which is limited by the intrinsic capacitance of the feedback resistor, R. The knee frequency is of course given by f = 1/(2*pi*R*Cr), where Cr is the intrinsic capacitance of the resistor. As...

I have 2 questions:(at least answer on question) 1) What is an amplifier? Is amplifier or a booster are same thing? What does an amplification do with signals? If an booster/amplifier is connected in a DSL line so will it amplify DSL connection to get better speed? 2) How to make a portable...

Hello everyone, I'm in the design process of building a 100W/ch audio amplifier. I would like it to sound as good as possible (willing to sacrifice power output for sound quality) and am looking for some design pointers. The output stage and driver stage will be solid state using 2sd845/2sb755...

We need a very-low-noise amplifier for a special application, and we buy such an amplifier with a noise bandwidth of 2.4 MHz and an amplification of 1000. To test it, we take a set of "perfectly" shielded standard resistors, connect each if these to the amplifier input, and measure the rms...

Normally in common collector amplifier, Rc (collector resistor) is absent or otherwise it is short circuited by capacitor. My question is: If Rc is present and not short circuited, does it affect the voltage gain? If it does, how it affects? Appreciate if someone can present clearly in...

The question is as given in the image attached entitled 'amplifier question' I would just like someone to check my working and verify whether it's correct or not. Thanks. And also want to ask on the second part which is 'what mathematical operation does this circuit perform?' Any help would be...

Homework Statement I have an inverting amplifier with v(in)=0.001sin(2000πt) and v(out)=-5sin(2000πt + 25)Homework Equations what is the input amplitude and at what degree? what is the output amplitude and at what degree? what is the voltage gain and at what degree? The Attempt at a Solution I...

Hi, I was trying to simulate a simple inverting amplifier in LTSpice. However, the results that I get don't agree with what I am supposed to get. Please look at the PDF attached. Based on the current law, it is easy to tell that Vout = -Vin. But I am seeing Vout = app. 0V. Am I missing...

Homework Statement I'm supposed to design and build the intermediate frequency amplifier portion of an am receiver. Homework Equations The Attempt at a Solution I've been looking around online and correct me if I'm wrong but the intermediate frequency amplifier takes an ac signal, filters...

Homework Statement What causes the output distortion seen in the above diagram? Output on right, input on left. The Attempt at a Solution This isn't homework, just something I can't figure out, playing with a simulator. The gain here is dependent on the input voltage... but why is the output...

Homework Statement How does a non-inverting op-amp circuit work? What happens if you make a non-inverting amplifier with Rf=Ri = 0? What would be the purpose of such a circuit?

Hi to all, For a project I need to measure output (as Volts) of a circuit. I want to do this with a SRS830 lock-in by using Labview application. Google search gave me nothing. If anyone knows how to set this up, please help. Thanks

Homework Statement for what purpose dodes are used in these projects. http://www.electronickits.com/kit/complete/elec/ck1600.htm http://www.electronics-project-design.com/MotorControl.html http://www.electronics-project-design.com/PIC-Microcontroller-Circuit.html...

Does anyone know how to build a low noise current amplifer that has wide bandwidth from ~10Hz to ~1Ghz, and together with high sensitivity (can amplify ~nA/pA) I need one for my project to amplify photocurrent, but am struggling to find any suitable products or design guides... cheers

hello all i wanted to make a circuit that takes power from the main a.c supply and increases its frequency( from 60 or 50Hz to about any frequency (lets say about 150KHz? or 15KHz?)), but the output voltage should not drop less than about 25 or 30v...

Hello everyone, I could not find the solution for my problems by searching the forums. Thus I am writing them here so would you guys please help me. There are two problems but it is not good to create two topics for this so I combine them here: 1. High Voltage Amplifier: We often work...

Gentlemen and ladies, I have an RF device and an in-line amplifier (specifically an AMMC-6220 - http://www.datasheetcatalog.com/datasheets_pdf/A/M/M/C/AMMC-6220.shtml). Certain units develop gain spikes at the high-freq band. They are in very specific frequency locations, and vary in amplitude...

why is an inverting amplifier and not a non-inverting amplifier used as a summing amplifier ? Why must the input voltages be inverted in a summing amplifier ? I am told that a summing amplifier is used as mixer in concerts where different music produced by different instruments go through...