Amp Definition and 370 Threads

Hello all. I have been looking into RF amps. I have come across the following cascode amp (from ARRL handbook 2014, p 12.10, FIG. 12.11. Thanks to Baluncore for the great reference). Here is a simplified version made with Qucs: My questions are regarding the capacitors, C1 and C2. Why are...

So I am in the process of building various solenoids for some projects I have. But the issue I have is that the battery I use is over heating. From my understanding, when I connect a circuit to a battery, the energy gets dumped very quickly and overheats the cell. Is there a way to calculate how...

Hi Forum, once again I seek your help I have a very good understanding of rotating magnetic field due to stator, armature reaction, and the phasor diagram. from energy point of view it is very clear that if Gov increases, while output voltage remains locked by the gird, Amp will increase...

I just finished a preamp/active crossover using the lm833n but the amp I need to run it with is a class D single supply board. and so the ground on the board is just negative. Can I run my [high pass/ground/low pass] signal into this amp? they are sharing a 24v power supply though and if I...

I need to run a signal through a configuration so that it has a gain of 1/2. I'm trying to figure out what the best way to minimize the noise for a low frequency input. So far I've only really thought of 3 ways to do this: 1. Voltage divider into a voltage follower 2. Measure the input so...

I have to find both of the voltage ratios. This is just ugly algebra. Here is what I came up with, and was wondering if I was correct. Thanks

Homework Statement Homework Equations The Attempt at a Solution I first found Vab which was 10 by using voltage division on the first device. By connecting CD to AB, the equivalent resistor is 80// 20, 16? I am not sure where to go from here.

Hi all. Hope you can help me out. I'm making a battery powered electronic cigarette and I need a momentary switch that is rated above 20amps at 8,4v. There tons of switches out there but the ones I like are rated at 3A/250VAC or 2A/ 36V DC etc, do these switches have a higher amp rating if...

I have this problem where it's asking for the unknown voltage V(b). What information I get is what is in the image provided and that R1= 1 ohm. Okay so as I start this problem I remember that the voltage drop across the terminals is pretty much equal to zero because the current flowing through...

Op Amp Circuit -- Simple non-inverting circuit question Homework Statement Image2. The attempt at a solution 0V*(236k/R1) + (-0.1cos(500t)*(236k/1k)) = 23.7cos(500t) Is this the correct setup of the equation because there is no R1 variable to solve for...?

Homework Statement Beta=100,Thermal Voltage=0.026 Volts, Va=infinity, and Vbe=0.75 Volts for the differential amplifier. Please look at the upload for a clearer picture. Homework Equations Ad=betaRc/2(rpi+Rb) Acm=-gmRc/(1+(2(1+beta)Ro/(rpi+Rb))) The Attempt at a Solution I have...

Homework Statement Please check attached image. I am doing some op amp practice problems and I came across this problem: I have to find the potential at the inverting input of the simple circuit model of the op amp. The op amp would be a basic inverting amplifier. I have to give the...

Homework Statement A CS amplifier utilizes a MOSFET with μnCox = 400 μA/V2, W/L = 10, and VA=10v. It is biased at ID=0.2mA and uses RD=6k. Find Rin,AVO,RO Homework Equations VAO= -gm(RD||ro) Ro=RD||r0 The Attempt at a Solution I drew out the equivalent circuit with...

Homework Statement What is the output voltage for an op amp whose non-inverting input is connected to ground and its inverting-input voltage is 4mv? Assume that the op-amp open-loop gain is 2*10^5 and its supply voltage is Vcc=10V Homework Equations Vo= A(vp-vn) The Attempt at a...

Hello, I am working on a lab for school and I am having a problem. I am attempting to build a compensated class b power amplifier. I understand the common emitter configuration (to boost voltage) and the class b push pull amplifier stage (to boost current). I understand that diodes in the...

Hello folks, This is my first post here, I hope I am posting my question in the correct place/manner? I am a mechanical engineering student taking an electrical class. We are studying op amps. The thing that is confusing me is current flow in the circuits. I understand that there is infinite...

Hello folks, This is my first post here, I hope I am posting my question in the correct place/manner? I am a mechanical engineering student taking an electrical class. We are studying op amps. The thing that is confusing me is current flow in the circuits. I understand that there is infinite...

Homework Statement Design a circuit containing a single op amp that can perform the following operation: Vo = 3*10^4(i2-i1), where i2 and i1 are input current sources Homework Equations The Attempt at a Solution Where I'm at right now, I am just using the equation for a difference...

Homework Statement I need help with finding an operational amplifier that could be cascaded with itself to produce a total gain of around 100,000, or 100dB. It also needs to be operational up to 1.5 MHz. This is for an rf amplifier for an AM radio I am building. Homework Equations...

Hello, I am wondering why the inverting terminal is the negative terminal and the non-inverting terminal is the positive terminal by name?

Making resonance using "simulated inductor" (op amp) I want to have a circuit that responds strongly (gives me a good measurable voltage) to a 10kHz sound input. To do this, I thought about hooking up a microphone and making a resonance circuit (using inductor and capacitor) to amplify the...

Hello everyone. I am studying internal structure of op amp and i don't know to solve some problems. The problem is that i have to specify and justify which inputs of the differential stage are inverting and non-inverting input and i don't know how to do it. I tried to find the answer on google...

I am working on a project that involves using an op-amp (among other ic's) to collect EMG signals from arm muscles. I couldn't get my hands on TL072. Will IC 741 be a decent substitute? TL072 -> http://www.ti.com/product/tl072 IC 741 -> http://www.ti.com/lit/ds/symlink/lm741.pdf...

Hi all, There is a CMS (Cern) program in which can display similar to the attached figures, do any one know what is it and how can I download ? S.

Hello I'm a bit stuck on this. The question states that the non ideal op amp (pictured below) in open loop conditions has an input resistance of 400kΩ, an output resistance of 2kΩ and a voltage gain of 500,000. I then asks to find the voltage gain, the voltage at the negative input terminal...

Hi, I was just curious, I am no EE, I am an ME and I am trying to make something smaller if you have read my other posts you might know what's it all about, anyways I've been reading a lot about single supply op amps and that's probably the best choice to reduce the amount of power my circuit...

Op Amp -- what is the slew rate limitation? Hello i would like to what is the slew rate limitation?? and why it is good to have higher slew rate? thanks

Hello, I am trying to figure out the transfer function for an RC phase shifter: http://imgur.com/2dnRYn7 (Picture of circuit) I am not sure how to calculate the output and specifically the phase of the output of this circuit. I understand that I need to consider one of the 'golden rules'...

What is the equation for Vout of the integrator op-amp?

Hi In the waveform picture i attached, I don't know why the square wave is floating instead of being on the 0 of the x axis. I also attached schematic of the pwm circuit. By the way, this is a pulse width modulator circuit made of 4 op amps, U2D is a schmitt trigger to generate sqaure...

I have attachted the question as a picture: my first attempt i calculated the voltage through the auxillary circuit to be 10V but i am confused of where the 0.5 A plays in this part, then i used nodal analysis to find the voltage input to the amplifier but up to that point i am confused of...

Homework Statement What exactly is op-amp saturation? Homework Equations V_{out}=A_{v}V_{in} The Attempt at a Solution I am doing a lab where we use an LM339A quad voltage comparator and a voltage divider network to create a voltmeter. A single red LED is connected to each of...

Homework Statement Derive the differential equation from the following circuit Homework Equations The solution needs to be a differential equation in standard form, so that I can solve the equation for the characteristic modes, zero-input response, zero-state response, etc. The...

From what I've read about transistors, I thought that I could find the hfe value in the data sheet, then apply a current to base and have the emmitter-collector throughput at a level of base*hfe. It sounded simple, and I was going to have a few different resistors for controlling base current...

I am in the middle of designing a low drift and low ripple power supply for myself. To control the output voltage, which ranges from 0 to 20V, I am using an op amp whose output is fed into a Darlington pair of power bjts. The output of the Darlington pair is both fed back to the op amp's...

Homework Statement Find Vo/Vin.I understand perfectly how to do this question. It simply involves an application of ohm's law to find i1, then KVL around the first loop. KCL at the top, and KVL around the second loop. Then to solve simultaneously. My issue however Is why the mechanics of...

Hello, I have been researching operational amplifiers because I plan on using some in a circuit I wish to build, but have been stuck for awhile on the concept of the maximum current that can be handled by the non-inverting input. It appears as though the input bias current is the current...

1. Homework Statement For this problem, the diagram of the circuit is attached. It was assigned to find the frequency response function of the circuit.2. Homework Equations E_o/E_i= -Zf/Zi3. The Attempt at a Solution I know for the top branch of the circuit, it has a negative feedback loop...

Homework Statement See attached picture. My objective is to calculate V0 on the 2k resistor. I'm used to seeing op amps that are more simple looking. I'm trying to reduce this op amp circuit to a simpler one (my attempt is the bottom picture). My question is: did I simplify the...

Homework Statement Given a DSB -SC system, with a message limited to B Hz, what is the minimum usable value of ωc or f0 (carrier frequency) Homework Equations Nyquist theory? Not sure how to apply. The Attempt at a Solution Only attempt has been through research.

Homework Statement The OP amp in the circuit is ideal. Calculate V0 if Va = 2V and Vb = 1VHomework Equations V = IR KCL, KVL, voltage division, current division,Op-Amp Output V = (Gain)(V+ - V-)(Gain) = -Rf / Rin Ideal op amp properties: Input Resistance RI = ∞ Output Resistance Ro = 0...

Hello, I am trying to make an audio amp on my breadboard, for fun I guess. But it's not working! I am running off of this circuit of the lm1875...

Hello all. I am currently trying to find the gain of a 2 stage amp. According to some notes I have, it is: A = A1 x A2 x (rin2 / (rin2 + ro1)) Where A1 = gain of first stage A2 = gain of second stage rin2 = input resistance of second stage ro1 = output resistance of first stage Let p...

Homework Statement Find the differential gain int terms of small signal parameters of the attached image. Homework Equations I don't think we need any equations. Just some basic mosfet knowledge. Not going to draw the small signal circuit, because it would take a long time. The...

So I've been lurking here for a while now, always checking other's solutions but this one has just got me stumped. Skill level: 3rd year electronic circuit design (about the level expected in Sedra & Smith from chapter 3 onwards) Homework Statement For the MOSFET differential amplifier in...

I have single 741 op amps running as unity gain amps and they work fine but when I tried to use a quad 741 op amp (LM348n) with the same config as the single 741 (short the inverting input to the Vout), the results are not correct. Can anyone provide a chip id and wiring config for a quad 741...

For a common base bjt amp, would I be correct in thinking that to measure total power consumed by the circuit, you would measure voltage from Rc down to Re (inclusive) and take a current measurement from between Vcc and Rc and then multiply together?

Hi guys :smile: This question has been bugging me for a REALLY long time so thanks in advance for the help :biggrin:! Homework Statement Calculate the Hybrid Parameters for an inverting op amp shown below: https://www.dropbox.com/s/45mjldud2ar5pwg/invOpAmp.jpg And I need to get it...

I have attached the circuit of interest. The question is to find Vd (drop across diode as shown in the attached image). Sorry about the handwriting on there (those can be ignored). The answer was given to be Vd=-5V. I can't figure out how they got that answer. I don't feel there is...

I built an inverting op amp circuit on a circuit simulator and did a transient analysis on it. I set the gain such that I expected a clipped output, but to my surprise it got clipped at +9V and -9V instead of +10V and -10V, which were the voltages supplied to the op amp. So why would this be the...