Op-amp Definition and 212 Threads

Homework Statement Derive the expression for the output Vo in terms of the input voltages V1 and V2? Attached image is the cir Homework Equations Inverting amp: A=Vo/Vi=-Rf/Ri Vout=-Rf/I_2 The Attempt at a Solution No idea how to go about this question with two input voltages.

http://img684.imageshack.us/img684/8362/opamp2.png Lets say we are given a non-inverting Op-Amp The gain of this circuit would be A = 1 + (R1+R2)/R3 if the switch is off. What happens when the switch is turned on? It shorts the R1 and R2 resistors am I correct? Does this mean that R1...

Homework Statement solving op-amp questions Homework Equations Values of resistors and capacitors The Attempt at a Solution Don't know. I want your helps. Thanks

Homework Statement 1. Using the LM324 op amp build an inverting amplifier with a gain of 50. Measure the cut-off frequency. 2. Plot your results on a graph as a function of log(frequency). Comment on the results Homework Equations The Attempt at a Solution Can some one...

Alright, so I have a problem on my homework set that features an Operational Amplifier. It's very similar to a "Integrator" Circuit which means the gain would be.. K = -1 / R*C. The problem is, the capacitor has been replaced by an inductor. I'm trying to find the relationship between vO and vS...

Homework Statement Homework Equations vo = G*vs where G = ((R1+R2)/(R2) therefore, vo = vs * ((R1+R2)/(R2) would vo be independent of Rs ? The Attempt at a Solution I assumed it was a Non Inverting Op Amp...but I haven't come across one with (two?) input...

I need to power an op amp and my only power supply availible is a 9-v battery, the goal is for the device to be portable. I need to feed into the + and - sides of the op-amp. Would I connect the positive terminal to one end and the negative terminal to the other or is there some other set up I...

Homework Statement [PLAIN]http://img546.imageshack.us/img546/2389/opamp.png Uploaded with ImageShack.us All resistances are "R". Find the output to input ratio for this Op-ampHomework Equations KCL, KVL, Voltage divider. The Attempt at a Solution I know no current flows into the Op amp...

Homework Statement I have attached the graph, and questions. Homework Equations The Attempt at a Solution For part a, do I just have to estimate how many db's are lost during one octave? One octave is halving of frequency, so could part a be approximated to be about 8...

Hi again, I have a little question about op amps and using them as ''Adders''. I currently study EE and Communications Engineering but our class still hasnt gone to the point of op amps. We will get there by the end of this semester. But we are asked to do a projects about everything we've...

Hey everyone. I'm wondering if I'm analyzing the attached op-amp circuit correctly. This is not homework, but rather, actual work. In the circuit diagram, VDAC is the output voltage of a DAC chip. VDAC and Vref are both measured relative to analog ground (AGND), as are the + and - power supply...

Homework Statement The op-amp in the circuit shown is ideal (please see attachment). The adjustable resistor RΔ has a maximum value of 160 kΩ and α is restricted to the range of 0.22 ≤ α ≤ 0.7. (a) Calculate the range of vo if vg = 40 mV (b) If α is not restricted, at what value of α...

Hi I'm somewhat new at this practical electronics stuff. So could use some help. I'm trying to debug a circuit made by a colleague who has moved on. It's a derivative of a non-inverting amplifier designed to amplify a signal from a generator. It works, to an extent, however the output...

Homework Statement Suppose you wanted to weight the inputs by different factors such that for instance Vo = V1 + 2V2 + 3V3. Describe how you would construct a circuit to do this.

Homework Statement The problem is shown in the attached PDF, it is basically applying a square wave signal to an op-amp integrator which has a resistor across the capacitor to correct for small DC signal. In this case it is given that the capacitor has an initial charge of 1 V on it...

Greetings, I have built a theremin that runs an output to a Velleman Mono 7W Amp. From the amp it then splits 3 ways. 1 to a speaker. The other two run directly to the horizontal and vertical connections of a deflection yoke in a 12V CRT television. This system works. I have sound from the...

I'm just wondering, if an op-amp is connected in a positive feedback configuration, should the output not saturate immediately? Here is an example circuit i made in pspice along with its input/output curve (V12 has amp of 3v). http://img689.imageshack.us/img689/1286/posfeedback.png As...

i am new to most of this so my confusion is basic. here is my problem. I am using a 555 timer to create a squarewave frequency of between 20-80khz BUT the output is 1vpp. i am using this to drive a motor and need to up the voltage and current. i know what i need to use i just can't...

Ok So I am pretty baffled at the moment. I am trying to get my inverting op-amp to work LM324. I have 15V supply going in. The + is going to ground with 5.7k resistor. The - has Rin and Rf both 10k. So this should output -1 * Vin. Vin is supplied by +2.8V from 2 AA batteries. But all I can get...

i have posted the pnp npn and op-amp water analogies. Could someone explain me pnp and op-amp water analogies.I have understood the npn water analogies but i have many doubts in it which i will ask after i understand pnp and op-amp water analogies. eventhough the explanation is given in the...

Hi All, I have a quick question for you. If you have a garden variety op-amp IC like the LM358 and you want to disable the output of the op-amp (assuming single supply operation), would it hurt it to "disable" it by cutting the supply or ground line to the IC assuming that signals can still...

Hello, I'm baffled as to why different frequencies affects the output (amplitude) of a integrator and differentiator op-amp circuit. I'm using a variety of frequencies (100 Hz - 10Khz), with a fixed 1V square wave input? Why does the frequency cause a change in the amplitude? This...

Homework Statement Calculate the out put voltsge on the amplifier with a voltage supply of Vs 100 mV and Rs = 1k , R1=1k R2=10k. power comes from a +-15 v supply Homework Equations V1-V2/r1+V1-V2/R2=0 V+=V- The Attempt at a Solution it is the Risistor Rs that i am have trouble...

How would you solve an RC op-amp circuit connected in a non-inverting fashion, such that the second resistor is replaced by a capacitor. This is not the usual differentiator or integrator circuit as far as I can tell? No specific problem, just generally speaking, how would you approach this

Hello, Lately, I have been venturing into the wonderful world of analog circuits and am currently working on debugging a circuit I made which is supposed to convert the current flowing through a very small sense coil I wound, into a voltage signal that I can read with my scope. The circuit...

What is the use of Buffer connection Amplifier? What is the common mode rejection ratio? What is the use of this in the op-amp applications, for example in difference amplifier and instrumentation amplifier? What are the application in Difference amplifier and Instrumentation amplifier...

hello guys I'm working on a line follower robot and i built following circuit(with the help of members in this forum :smile:) as line sensor. https://www.physicsforums.com/attachment.php?attachmentid=20782&stc=1&d=1254182755" it uses LM324 opamp as a comparator and RED LED as a sensor...

I have been studying op-amps in my 2nd year circuits class and I had a question to ask. From what I understand the output voltage is supposed to be < power supply voltage. If this is the case, why do we use op-amps ? I mean if I have 15V and I need to power something why can't I just...

I'm designing a circuit for experimental use. I'll make this as quick as possible. Browsing other circuit designs on the web, I initially noticed "followers" placed between other op-amp app's (adders, integrators, inverters, etc). From what I can tell, putting in followers like this must be...

Homework Statement Calculate the output of the op-amp as shown in the given circuit. http://img9.imageshack.us/img9/7554/184v.png (Answer=0) Homework Equations Kirchhoff's Current Rule The Attempt at a Solution By applying KCL, I1+I2=I3 V1/R1 + V2/R2 = Vo/R3 Substituing...

Homework Statement A current-to-voltage converter The current source has a finite output resistances Rs, and the op-amp has a finite open-loop differential gain Aod. Show that the input resistance is given by Homework Equations Rin = RF/(1+Aod) The Attempt at a Solution Rin = RF...

I have a simple op-amp circuit that I need help understanding: http://img200.imageshack.us/img200/3939/opamp.jpg I know that the positive input is noninverting and the negative input is inverting. I thought Vout was calculated by (V2-V1)(Aol), but I guess I am wrong. Can anyone help me...

I've gone through some light theory on op-amps and can understand that fully. What I don't understand are the real-life applications for integrator and differentiator. What does the output signal looks like? Can somebody shed some light on these?

As part of our project work we have to design a circuit using op-amps on PCB giving reasons why we used the resistors of particular value etc. any suggestions or references?

have 2 make project which involves comparing op-amp 741 and anyone of the latest op-amps..can anyone suggest the any latest op-amp??

Certain questions involve finding input resistance for circuits (e.g. inverting or non-inverting configuration). I know ideally the op-amp has infinite input resistance but i don't know how i would be able to calculate the input resistance for non-ideal circuits? Thank You.

Homework Statement You have an op-amp circuit, a very simple one... All it is is a signal produced (triangle wave) from a generator that is sent into both the inverting and non inverting inputs. what does the output wave look like?? The Attempt at a Solution Im pretty sure this...

help me here...symbol of an op-amp is triangular in shape...i need reason for this...why it is so...or where i can find regarding this.. similar que for transistor also...

guys, i need some help... is it possible to construct a variable-output current supply using op-amp(s)? if so, can anyone help me about how to construct one? thanks :)

Hi, I am new to circuit designing and I have a question on one of the parameters in the spec sheet of op - amp. I don't quiet understand (see the graph) what does the output saturation voltage v/s (overdrive voltage or load current) is and why is it almost the same for outout being low or...

Op-Amp: "voltage-follower" question Hi all, ... If a simple op-amp circuit is described as: -> being in a "voltage-follower with-gain" configuration, and -> having a resistor ratio of 9:1 ...Where are the two resistors positioned with respect to the op-amp circuit element, and ...How...

Homework Statement Design a non-inverting op-amp amplifier for a voltage gain of 20 and a load of 1k ohms. Determine the output voltage and output op-amp current if V input = 0.1 sin (omega*t) Volts. Homework Equations Voltage Gain = V output/V input Voltage Gain = 1 + Rf/R The...

In my text it says, "As a result of the negative feedback, it can be shown that the closed-loop gain is almost insensitive to the open-loop gain A of the op amp. For this reason, op amps are used in circuits with feedback paths." I am a bit confused on what it means by closed-loop gain is...

I'm having trouble understanding how this actually works. I understand that it integrates the input voltage and that the output voltage is the same as the voltage passing over the capacitor in the circuit. What i don't understand is why this causes the ramping effect? I'm thinking it may have...

Homework Statement For the attached circuit: R1=1Mohm, R2=10Mohm, C1=1uF. If the initial capacitor voltage is 0, find the output. Will this circuit work in practice? Explain. What does this circuit do?? What does this circuit do? This circuit integrates and is a low pass filter...

For the attached circuit: R1=1Mohm, R2=10Mohm, C1=1uF. If the initial capacitor voltage is 0, find the output. Will this circuit work in practice? Explain. What does this circuit do?? What does this circuit do? This circuit integrates and is a low pass filter. Will this circuit work in...

Hey there This should be nice and simple. Here's the deal-- I was asked to design an Op-Amp Integrator circuit. For a 500Hz square wave input signal that oscillates from +/-0.5v, I was asked to design for a triangle wave output which oscillates from 0 to -5 volts. I designed the circuit...

Hi, I'm currently making a hydrophone and I'm planning to use a piezo crystal as a sound receiver whose output I then intend to put through an op-amp. Berkeman recently raised an interesting point about voltage issues with op-amps so I thought I'd pose this question before proceeding any...

Hi, My shiny new op-amp arrived today for my hydrophone project. Great. Only problem is it's difficult to actually see it, it's so small. The pins are barely a millimeter apart and obviously I can't solder anything that small. So is it possible to get harnesses which increase the size of the...

Homework Statement Hey guys, quick EE question for ya. This is the end of a signals and noise assignment and i think I've got it but I am not sure so i thought id check. Attached is the question, doing the 2nd part of 13 The part that isn't shown that we need is that the band pass is between...