Amp Definition and 377 Threads

http://pokit.org/get/8119a4b8a37171c67971c3fb13b33063.jpg Consider picture above. I understand how an integrator behaves when the capacitor is full. It(capacitor) acts as infinite resistance ergo open loop so we get positive saturation at the output. What I don't understand how come we are...

I'm unsure what the purpose of this is. I have looked it up but can only find some explanations stating "role is to convert the differential current input signal to a single ended voltage signal without the intrinsic 50% losses and to increase extremely the gain." I'm not sure what double...

Help me ! I have designed a multi op amp circuit, and am now looking to build it. will i find any practical issues with such things as external interference, resistor tolerance, op amp imprfections, bandwidth issues, internal resistance. If so why?

Homework Statement I have to find the transfer function of a linearly and ideally operating OP Amp. http://i.imgur.com/u3f6E.jpg Homework Equations The Attempt at a Solution I know that the current through the capacitor, R1, and R2 is the same, so i=C(dv/dt) = Vin/R1 =...

STK 4191 amp. burning resistor :( I just built a STK 4191 amp. when i supply power a 100Ω resistor (1w) near the IC starts smoking. there're no short circuits across the ICs pins or anywhere on the board and i took all precautions when soldering the IC on (was done with heatsink + 40mm fan...

1) What is a typical voltage level coming from an 8Ω speaker being used as a microphone to record a human voice at average volume? I kept forgetting to bring it to school to measure it's output with the oscilloscope, so I'm wondering if anyone here knows it. 2) I seem to remember reading...

Homework Statement A certain op amp has the maximum offset voltage magnitude of Vos = 2 mV, the maximum bias current of Ib = 100 nA and the maximum offset current magnitude of Ios = 10 nA. The op amp is used in the noninverting amplifier shown in the diagram below. Find the worst-case DC...

Homework Statement A certain op amp has a maximum output voltage range of ±9 V. The maximum output current magnitude is 20 mA. The slew-rate limit is SR = 300 kV/s. The op amp is used in the amplifier circuit, shown in the diagram below. For a frequency of 10 kHz and RL = 2.2 kΩ, what peak...

I am trying to understand how some of the standard ICs work in terms of simple components I understand, i.e. transistors, resistors, capacitors, and inductors (although I doubt there are any inductors in an IC.) I was trying to build and op amp from transistors, resistors, etc, and I noticed...

Quick question: how do you solve an ideal op amp circuit with the two terminals connected to independant power sources?

Homework Statement I need to find the steady state displacement amplitude for a driven harmonic system. Homework Equations mass (m) = .5kg stiffness (s) = 100 N/m mechanical resistance (Rm) = 1.4 kg/s force (f) = 2cos5t The Attempt at a Solution What I know: angular freq (w) = 5...

Hey guys we're learning about op operational amps and I'm having a struggle on how to transform any given circuit with an amp into its equivilant. i understand all the math involved once the equiviliant has been found, just getting to that point is a bit confusing for me. An example i found...

I have a treadmill that has a display monitor that uses either 4 D cell batteries or an optional adaptor. The back of the monitor states it uses a 6v 1.66-2.0a/max input. I purchases a universal power adaptor that has a fixed amp rating of 3 (6v obviously is an option). The question is: what...

hello, I have a strange problem! I wanted to amplify my signal and i used 2op amps, each of them has a feedback resistor between (-) pin and output( pin 2 and 6 in 741) the ratio of resistors(r2/r1) is 150, but my signal only amplify 5times! I change the R2 resistor but nothing changed! i put...

hello, Is there a limit for the numbers of op amp we use to amplify a signal?! I mean is there a problem if I use 3 or more op amp to amplify a signal?!

Hello. I have a very quick op amp question. I'm trying to understand an omp amp. My question is will vout of an op amp go to zero if the inverting input is greater than the non inverting input ( even if there's a negative/positive feedback)?

I need help calculating the R values for this circuit from the following article: AN HIGH RESOLUTION RESISTIVE PROBE FOR NONLINEAR ANALYSIS OF TWO-PHASE FLOWS L. Cantelli, A. Fichera, A. Pagano This is only a section of the circuit, there is more but I'm only interested in this part of...

Hi, I was wondering what the disadvantage of using a non-inverting summer was rather than using an inverting summer. I was told that inverting summers are better, but not why they are. I ask because I'm making a circuit that performs a center of mass calculation: (V1 + V2) - (V3 + V4) =...

Hello, I have a small (24 Watt) guitar amp which I'd like to retrofit with a battery for outdoor playing. I actually study mathematics and do electronics mostly as an hobby, so I may miss some fundamental things (i.e. bare with me). Basically, I have two little problems which I'd like help...

Will an audio amp burn up if the speaker connected to it has a lower impedance than the amp's output impedance?

current gain of an op amp? Homework Statement need to convert current(output of a detector) in the range of pico amps to voltage between 1-5V Homework Equations (to connect to an adc) The Attempt at a Solution I've connected an op amp(for current...

A coworker has a well pump that is a 0.5 horsepower, brand new, no issues... He says the normal amp draw is 4 to 5 amps. This is puzzling because it is a 240V pump and the math works out to (746/240 = 3.1/2 = ) 1.55 amps. What is going on?

Homework Statement i have this circuit http://screencast.com/t/6rgXUvZW but I am not sure if i have set it up correctly, firstly is where I've put the multimeter V out? I am not quite sure and are the Vins supposed to be in AC or DC? and are they supposed to be connected to ground like i...

Superb Old Labtech Speakers to add to my RV without 120 Volt AC The Labtech AC adapter's output is 15VDC 1000ma. Using my existing 12VDC power supply (2 - 6VDC inline Deep charge Batteries) may I boost this output to 15VDC by adding 2 ?or? 3 Duracell Rechargeable AA batteries. Duracell...

Homework Statement Find the output voltage Vo in the following circuit Homework Equations V = IR The Attempt at a Solution Hey everyone, this question has me stumped. The answer to the question is -IR_2 but I'm interested as to how this answer comes about. I'm not particularly amazing at...

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 I have done this in a lab and then graphed it, it seems to be around...

So, my goal is to be able to take two walkie talkies and put one of them on a near space balloon and have a microcontroller send data through the walkie talkie on the balloon down to the one on earth. I'm not sure it would reach all the way back to Earth so I thought of putting a small linear...

Hey everybody, I've been trying a bit of an experiment involving cascading an inverting logarithmic amp with an inverting exponential amplifier. Between them I put in an inverting buffer (see attached diagram). Now the thing is, when the inverting buffer has unity gain everything works as...

Greetings Physics Forums, I'm reading up on Radio Circuits and studying for my General's Amateur Radio License and was learning about AM Demodulators. I understand that in AM you can use a peak detector to get the modulated audio out however in SSB radio don't you have to double the...

Hi there, does anyone have experience with amplifiers in cryostats? I would like to have one close to the sample inside the cryostat. The problem is that there will be at least 4T of field with large gradients and I guess that I have to insulate it. The sample is at 15Kelvin but I am thinking...

Homework Statement The problem is within a lab, so I guess I need to give some background first. Pretty much, I'm starting with the circuit shown here. http://imgup.com/image-EC69_4D91309A.jpg For the part of the lab I'm interested in, the values of R1 and Rf were put as 1 kohms and 10...

Homework Statement Homework Equations KCL & KVL. The Attempt at a Solution Using KVL: -9 + 10kI1 + 6 = 0 -10 + 20kI2 + 6 = 0 12 + 30kI3 + 6 = 0 40kI4 + 6 = 0 :. I1 = 0.3mA I2 = 0.2mA I3 = -0.6mA I4 = -0.15mA Now here's where the problem is. When I take KCL at the...

Hi friends, I am having a little difficulty understanding how amp hours being pulled from a battery are calculated, any help would be much appreciated! I have a 12v 125Ah deep cycle battery. Research has told me that for DC appliances you divide their wattage by 12V to give the amps, so...

Hi! I solder the following circuit: http://en.wikipedia.org/wiki/File:Op-Amp_Non-Inverting_Amplifier.svg With an opamp of +-5V or 0-10V operation I use a 12V dc supply and give a Vin of 0.05V with resistors 10k and 1k. For all cases no matter what I supply I get Vout = Vsupply...

Homework Statement Hello everyone. I tried solving this ideal op amp for V0 but kept becoming confused because of the structure at the bottom. I only have experience solving ideal op amp questions when they are grounded and have not encountered one like this before. All the data is...

hey guys i plan on fixing up this old behringer vintager that honestly sounds like a piece of dirt. the amp is a solid state/ tube hybrid with 1 12ax7 tube in the pre amp. i plan on taking it and just using the fx loop out to only get the pre amp section and hook that up to my computer. from...

Homework Statement An original picture can be seen http://images3a.snapfish.com/232323232%7Ffp733%3A%3A%3Enu%3D52%3A%3A%3E379%3E256%3EWSNRCG%3D335%3B%3B7%3A542347nu0mrj". Homework Equations The Attempt at a Solution I am not really sure how to start, how would I find out what...

Homework Statement A picture of the original problem can be seen http://images3a.snapfish.com/232323232%7Ffp733%3C2%3Enu%3D52%3A%3A%3E379%3E256%3EWSNRCG%3D335%3B%3B84268347nu0mrj" along with some extra labels. Homework Equations superposition The Attempt at a Solution So I tried...

Homework Statement Find Vo(s)/Vi(s) for the OPAMP circuit in the attachementsHomework Equations V = iR, Kirchoff current law. 1/sC = Laplace transform of capacitor impedance. The Attempt at a Solution Make the voltage at the node = v'. ir1 = (vi - v')/r1 ir2 = v'/r2 iz = (v'-vo)/z z =...

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.

Is there an equation with which I can estimate the flow rate a fan will generate at a set diameter, speed and angle of the blades? Assume that this is a simple box fan that you would put in your window. I'm assuming that you would have to determine the axial speed of the air given the angle...

Inverting amplifer question http://img210.imageshack.us/i/electronicsquestionsq30.jpg/ Can do part a) ! Vout/ Vin = -R2 / R1 and found part d) in a book, that closed loop gain is less but more linear and am able to draw the graph. Any help with b) c) e) f) would be great, particulary...

greetings, At high frequency (more than 20kHz) the reactance of capacitor is very small and act as short circuit.this increase the loading of next stage.whats the meaning of increse of loading in next stage? RC coupled two stage amplifier circuit is here-...

I am trying to drive a NPN transistor with a LM324 op amp. The darn transistor does not turn on when driven by an op amp. This is basically a current limit circuit. Instead of using a large value sense resistor, I used a small resistor(0.1 ohm) and used an op amp to sense and increase the...

Hello Am reading about amplifiers, and the articles i read suggests that for a successfull amplification the op amp should have an input impedance and zero output impedance. I want some explanation about this information, why the input and output impedance are important factors?

Homework Statement I have a question which asks for the weighting factors associated with several input voltages to an op amp. What is meant by this? This terminology isn't used anywhere in the text.

Hello. I have developped a transimpedance amp using LF356, unfortunately I get an oscillation at 500 kHz of low level (10 mV) but not acceptable. I've tried all classic tricks, decoupling power supplies ... With no real improvement and so I'm going to developped a similar amp using discrete...

This is a very silly question. I can't believe I have forgotten. I have a 30v bench power supply and I am looking to test an op-amp running at +/- 15v. I have a supply which has a negative output/ positive output and inbetween a green common/earth output. How do I wire them to produce the +/-...

What is the output of the op amp when either Vcc or Vee is not connected. I simulated this and got Vsat. +Vsat when Vee was missing and -Vsat when Vcc was missing. But I don't know why the output saturates to +Vsat, even in a inverting configuration. Shouldn't it go to ground, since the...

In a pirani vacuum gauge the pressure is determined by the rate at which heat is conducted away from a resistance wire by gas moleculs. The heat is supplied using a constant current source and the rate of heat dissipation determined by the temperature induced change in the resistance of the...