Opamp Definition and 151 Threads

hello dears i have a question at op amp could i use the comparator to compare between to differential signals .. more specific if i have tow signals out of phase (180) and unequal amplitude could i use op amp comparator or differential amplifier to distinguish which of them is higher amplitude ??

Thank you for reading my post. I'm currently studying Op-amp, and there is a homework about LH 0005 of National Semiconductor for me to do: determine the collector current through each transistor I'm trying to find the IC2 but don't know how. Please help me with this :) Homework Statement...

According to my professor's model answer for an assignment, when we derive the transfer function of an op amp circuit, we have a "K" value, which is the open loop gain of the op amp (I am not 100% certain), multiplied to the op amp circuit (1+R1/R2 for non-inverting amplifier for example). I...

I want to detect whether potentiometer output voltage is increasing or decreasing and convert this to a digital signal. the circuit must be able to sense tiny voltage changes (order of 10mV) and with high speed. all I am interested is if Vout increases or decreases not by how much increasing V...

a bowl is filled with tap water .electric current is made to flow due to electrodes attached to rim of bowl(opposite sides of bowl) i have 2 sense pins inserted into the water between the electrodes . how can i convert this analog signal(vd across sense pins) to a digital signal to detect...

Im working on a project which cycles through stop,forward, back,left, right modes of a bot using light pulses as input . light source is laser pointer , room is dark the circuit is not mounted on the bot the circuit - light pulse -> ldr-> bc337transistor ->7404 NOT -> 4017 decade counter ->7483...

Homework Statement Homework EquationsThe Attempt at a Solution (a) [/B]We can assume for ideal op-amps that there is: infinite input impedance low output impedance the potential for infinite amplification (b) Non-inverting op amp (c) This is the part I have trouble with. There is three...

Homework Statement Find the differential equation for Vo Homework Equations KCL The Attempt at a Solution At node v1: ##\frac{V_1-V_{in}}{R_1}+\frac{V_1-V_p}{R_2}+C_2(\dot{V_1}-\dot{V_2})=0## At node vp: ##C_1\dot{V_P}+\frac{V_P-V_1}{R_2}=0## At node vn...

Homework Statement Homework EquationsThe Attempt at a Solution Nodal Equations By property of OpAmp, V2=Vo eq1:\frac{V_{1}-V_{in}}{R_1}+\frac{V_{1}-V_{o}}{R_2}+C_2*(\dot{V_1}-\dot{Vo}) eq2: V_1=C_1R_2\dot{V_o}+V_o eq3: \dot{V_1}=C_1R_2\ddot{V_o}+\dot{V_o} Sub 2 & 3 into 1...

Hello everyone, I am having an issue where the output of the op amp for the following circuit works fine under no load and allows me stable output voltage. When I close the switch and apply the load, the output voltage decreases (as one would expect), however, the op amp output doesn't...

I am embarrassed to ask this. I just want to make triple sure about this stability condition. In the attached plot, I have the open loop gain and phase plot in light green and closed loop gain and phase plot in dark blue. You can see the closed loop gain is 30dB which is about 22 or so. I want...

i connected pin 4 and 8 to gnd and +5 v respectively .when pin 2 touches wood, or hand pin 1 is high. i understand skin is capacitive , but wood?

Dear electrical engineers, Here a question from a serious electronics n00b =D. I tried to build a system as shown in the image. I have a photodiode which gives me a clock signal in the range of 200 to 500mV. Frequency will be in the range of 100 to 1000 Hz. I would like to amplify this...

Problem: my photo diode receives pulses of width 10ns-150ns and repeating at rate of 1Hz-50KHz the current from photo diode depending on incident light can go from 10nA-100mA, in a nutshell, my application tries to digitalize the analog pulses for pulse width measurement so i have 'only' two...

Problem Statement: my aim is to digitalize a 10ns narrow pulse coming from a photo diode with current ranging from 10nA-70mA, as its impossible to cover this dynamic range of >60dB using a single TIA i have an option of separating it to two channels as below using two diodes ofcourse Lowest...

Homework Statement to prove vo=(2R2/R1)[1+R2/Rv][vI2-vI1] and Rv is variable resistor Homework EquationsThe Attempt at a Solution upper: 2 is 0V? and then Rv,2R2 form a t-network? bottom:3 is 0V? if not how can i calculate?[/B]

Hello. I am looking to amplify a sinusoidal signal generated from an AD9850 DDS. It appears the output is 1Vpp @ 27.12MHz when connected through a 50ohm cable to an oscilloscope. I need the total power output to be 5watts after amplification with a very clean sinusoid. The output will be...

Homework Statement Homework Equations H(s)= Vo / Vi Ideal op amp: V+ = V- Vo = V- The Attempt at a Solution To simplify the circuit, I noticed that the 200 ohm resistor and 60 microFarad capacitor are in parallel so: Zp = (R/sC) / [(1+sRC)/(sC)] = R / [(1+sRC)] Seeing that the Zp is in...

Homework Statement i know that it is a summing amplifier and i have vout at 2v, however in the question it asks for I1,I2,I3 and V2(vin) i have I1 and I3 but having trouble working out I2 and V2 Homework Equations Vo = - RF ( V1 / R1 + V2 / R2 + V3 / R3) The Attempt at a Solution when...

Hello, I need an opamp that can output +/- 150v without paying $500 for a high voltage opamp. I need a workaround solution, I'm thinking of a 5x DC gain of the opamp output voltage but I am totally clueless on how to achieve this. Any ideas?

It is known R4=R5=1.2k. My task is to calculate amplitude of oscillations at v0: Opamps and diodes are ideal. I did analysis of circuit without amplitude stabilization and I got oscillation frequency, but I can't figure out how diodes stabilize amplitude in this circuit. Any sugestion...

Hi folks, I would like to clarify few doubts on my mini-project as mentioned below: I am designing a small kit using a transistor (2N3904) and an OP-AMP (LM741- Voltage follower) with few resistors connected to them. My power supply voltage value is 5V. Please refer to the below picture for...

Hello. Here is my task: In oscillator circuit ideal opamps are used, it is known R=10K, C=10nF. a) Calculate frequency of oscillations, b) If Vcc=Vee=15V, calculate amplitude of voltages in points A, B and C. a) Here is my solution. I cut output loop, applied test generator and found loop gain...

Here is my task: Construct circuit ? which uses power supplies +12V and -12V and gives output voltage: where Here is circuit: I solved it using 4 opamps: First opamp scales V3, second integrates V4, third sums the results of the prior two circuits and fourth inverts signs in sum...

In the figure it could also be possible to connect the transistor Q1 as a diode by shorting its collector with its base ..but instead it is done by keeping both base and collector at ground... The text have to say that if it would be connected the other way(i.e by shorting collector and base...

Please help me on this... The following circuit is of an active rectifier..The inclusion of a diode here signifies a voltage follower for positive Vin voltages ...but for negative Vin diode is off hence the out voltage Vout is zero...and the output of the opamp goes into negative saturation...

please help me guys My inference to above circuit... The negative cycle of the output signal from the driver is entirely clipped off before getting to switching transistor..this however don't have any effect on output because the transistor won't conduct for negative cycles but when due to any...

Hello. I really don't get a concept of a way to generates negative voltage as a one of the supply voltage to typical OP-AMP. (Operational Amplifier) The output voltages is supposed to swing to more than 10 V thus supply voltages to OP-AMP should be +15V and -15V. I'm thinking of supply these...

Homework Statement Select a suitable opamp to interface the hydrophone. Ideally the hydrophone noise will dominate the system. Consider the input referred 1. voltage noise, 2. current noise, 3. input capacitance, and 4. input impedance of the opamp...

Hi all, I am currently studying OpAmps and one of the topics that came up was the applications of OpAmp circuits. In particular, I was learning about precision rectifiers (using non-inverting version of it, thus the diode is pointing away from the "out" terminal of the OpAmp). The thing I...

Given this ideal op-amp, determine Vout if Vin = 2V and Vs = 15 V. So I know that the ideal op-amp has infinite gain. As the difference between V+ and V- is substantial (2V), wouldn't that mean the output would theoretically by infinitely large but instead max out at Vs? Am I understanding...

Hello everybody, nowadays I am working on shaping amlifiers and need guidiance about how to design one and do its simulations before pcb design and manufacturing. When googling about shaping amplifiers i found documents mostly about filters (active and passive), which i know works for rejecting...

There's a LM741 OpAmp in a circuit, that's amplifying a signal (from a hall effect sensor) with about -0.5/+0.5 V voltage swing. The hall sensor requires about 1.2 V to operate. Since I'm using a single power supply for the OpAmp (at ~10 V), I figured, that I need to shift the voltage to power...

So in the input of this buffer circuit I have a small AC signal (μV) that is capacitively coupled to an op amp. What is the role of R? I read that it is to provide a bias current path and it has to be large in general but I can't understand it. Any help much appreciated

I am having a play about with the differential amplifier using a LM324 and have shorted both inputs and set them to 3V sine wave at 100Hz. i understand that in a ideal op-amp the output should be 0, how ever i am unsure of what is happening at the output... i increase the frequency every 1Khz...

Hi! Here is my task: OPAMP circuit and output voltag are shown in image below. Assuming that OPAMP is ideal, come up with a solution by hand. Then change capacitor's value from 200nF to 33nF and output voltage will be: Explain why output voltages are different ( first has triangle shape...

[FONT=Georgia]Hi! Here is my task: OPAMP circuit and output voltag are shown in image below. Assuming that OPAMP is ideal, come up with a solution by hand. Then change capacitor's value from 200nF to 33nF and output voltage will be: Explain why output voltages are different ( first has...

Hi! My task is to calculate gain A=Vo/Vin for circuit on scheme (OPAMPS are ideal): Since OPAMPS are ideal, input currents are zero and V1=V2=Vin, V11=V22=0: KCL for node 0 suggests us that current through R4 (I4) must be zero: On the other hand, we can calculate I4 as: :confused...

Hi! Here is my task: Find output voltage Vo if Vin1=3V, Vin2=-2V, R1=R2=R3=100KΩ, R4=300KΩ, R5=150KΩ, VCC=15V. Applying KCL at node 2 we get: $$-Iin2+I5-Icc=0$$ $$-\frac{V3-V2+Vin2}{R3}+\frac{V2-V3}{R5}-\frac{V3-V2+Vcc}{R4}=0$$ $$-\frac{Vin2-V2}{R3}+\frac{V2}{R5}-\frac{Vcc-V2}{R4}=0$$...

I'm struggling to compute the noise voltage due to the thermal noise on the resistors of an op-amp circuit, configured as a t-network. If it were a single feedback resistor, the noise voltage referenced to the output (RTO)would be given by sqrt(4KTRB). I'm not sure how to combine them...

Homework Statement Find the voltage gain, V0/Vs, for the circuit below. All resistors are in Ohms. Homework Equations I identified this as a non inverting amplifier. Therefore: V_{0}=\frac{R_{S}+ R_{f}}{R_{s}}V_g The Attempt at a Solution Vo = 8/3*V1 (v1 = output of U1)...

I have a 30V, 500mA power adapter that I would like to step down to 15 V with a voltage divider and run through a voltage follower (opamp) for connection to an experimental circuit. I have really only ever used 741s, and honestly have no idea how to shop for an appropriate opamp here.

Homework Statement For the following circuit, if Rth = 50kΩ, Ri = 1TΩ, and Ro = 50Ω, calculate the output voltage. Do not neglect Rth, Ri, or Ro. Circuit is here. Homework Equations Possibly KCL and/or KVL, possibly the non-inverting op-amp equation Vo=(1=Rf/Rs)Vi, Ohm's Law V=iR...

Hi everyone, I was trying to solve this problem. Here at calculate 3 db frequency the gain should me 1/sqrt(2) times of the maximum voltage gain. So I calculated maximum gain which is 1+6/3=3 ( capacitor will be open for maximum gain). At 3db gain will be 3/1.414 3/1.414=(1+6k/(3k||(1/jwc)))...

Homework Statement Trying to figure out what this opamp does but can't pinpoint it. Homework Equations The Attempt at a Solution The one with the capacitor looks like an integrator. I attempted to build this circuit to see what it does. At node B I saw a triangle repeating waveform, node A...

Homework Statement Homework Equations Superposition Non-inverting OPAMP: V_out = (1 + R/R)V_in = 2*V_in2 Inverting OPAMP: V_out = -V_in V_os = 2.5mV The Attempt at a Solution 1. V_in enabled, V_os disabled V_out1 = -V_in 2. V_os enabled, V_in disabled To get V_out2, use the non inv...

An opamp circuit was given in the homework forum: There the circuit was analyzed with the usual assumptions of opamp ideality. But, if the circuit is analyzed with one change to ideality, namely the opamp voltage gain is set to 7 rather than ∞ (this brings with it the change that v+ ≠ v- any...

Homework Statement Hi, I'm trying to figure out the component values(Rf and C) for the circuit given. The circuit must be designed so that it has a cut-off frequency of 1khz and a low frequency magnitude gain of 1. I know how to do it if i ignore the unity buffer in front but I'm not sure how...

Homework Statement This isn't necessarily a direct homework problem that I have, but it is brought up a few times in homework problems for the chapter I'm reading through in my circuits book.. It will ask me if a certain voltage exceeds the saturation (or in other problems, at what value of...

How to power an OpAmp using two batteries, so there's no connection to mains ground or neutral? This circuit requires ground to force the node connecting the batteries to be at zero potential. How can I achieve the same result without grounding? thanks.