Amp Definition and 377 Threads

I have tried many times testing some Op Amp LED flashing circuits on a breadboard from the internet. So far, none of them works. The photo above is one of my attempt using a Ti IC chip LM358. I have double checked my wiring and swap the 100k with 10k and 56k resistors. what is the problem...

I'm building a microphone amplifier for a bot that will respond to frequency commands between 1kHz and 3kHz. I have an ADMP401 mic but need to choose an op amp. Someone in class told me the LM348 quad amp is best but not why and I need to know how to make that decision.

Homework Statement Homework Equations V=IR KCL/KVLThe Attempt at a Solution I have a similair problem to this one in my notes and I know how to solve this circuit, but I am confused on some parts of it. First, at V1 why can we say the voltage there is 0V? Is it because it is connected to...

Homework Statement If a 5 amp unit can cool 4 cups of water from 75 to 50 degrees fahrenheit in one hour, what temperature could a 30 amp unit cool 128 cups of water in the same amount of time? Is there enough information here to get an idea about what the 30 amp unit would do? If so where...

Hi, I wanted to ask if there would be a problem or two if I placed my pc on top of the head of the marshall half stack amp, the harddrive is about 65ish cm away from the center of the speaker (4x12inch speakers) and the power supply of the pc is about 50ish cm away from the center of the...

This is my first try at building everything myself. Programming the G Code to cut the chassis on my old Linux computer took a bit of thinking...lol Here is a short video. A few photos so far. I will post the schematic when I finish it. Cheers, Billy

Hi, Is there any reason I should not use the 5VAC or the 6.3VAC taps on the power transformer and design a rectifier circuit to power a LED? Thanks, Billy Be back in a bit

Hey guys so I have had this idea for an electronics project for a long time, and it basically goes like this. It's a floating speaker box for floating on the river when we are rafting. Design considerations are that it would have to be unsinkable (as much as possible), also loud and with a...

Hello I am developing a low noise preamp and would like to change the roll off of my design to sharply decrease the gain for very low frequencies "1-5Hz". The results of my current design are as follows. I would need something that looked more like this.. I understand the simple equations...

Hey, Im in the process of building my final project for an engineering electronics course. The requirements: - 3 Inputs - mixer stage - driver stage 0.5 - 3watts ( my speaker is 3 watts) - output to 8 ohm speaker. Questions - Anyone have any good links regarding helping pick BJT, Jfet or...

Homework Statement Homework Equations The Attempt at a Solution I am not really sure how to do this problem. How can I convert from db to linear terms just given db? Don't I need more information? For do I have to do a system of equations or something using the Power gain =...

The output voltage of op amp is greater than the power supply voltage (+/- 5V). Is Op amp burned out?

Hi guys, I was given this Mesa Boogie Nomad 45 chassis. I repaired it yesterday and have it working more or less well. Mesa does not install adjustable bias in any of their amps. I want to install a trimmer pot to control the bias. Where in the circuit should I place the trimmer resistor and...

Hi Guys, I am having issues trying to repair this amp. http://www.tangible-technology.com/schematics/fender/HR-Deville/Hot%20Rod%20DeVille.pdf A little history is in order I guess. I have not been working on guitar amps for too long, several months now. I have repaired perhaps fifty or so...

Currently working through a chapter on op amp circuits, fundamentals. Came upon this practice problem in the section on inverting op amps imgur link: http://i.imgur.com/2DrQLXk.png imgur link: http://i.imgur.com/7KRKzKC.png A working of this problem is not given. I got the correct answer...

hi, i reallyt need help in this question. i tried this but i am not sure how to start this, so if you can provide me little help i will really appreciate it its based on OP AMP circuit thanks guys

Homework Statement [/B] Hello, I have attached the problem below. I am trying to find the value for v1 - v2 and iA. The given values are V, RA, and R for the other resistors. There are no numbers. Homework Equations It is given that the op amp is ideal, therefore v- = v+, and i- = i+ = 0 for...

I'm trying to replicate a simple single bubble sonoluminescence (SBSL) experiment. I have several sources that I'm using for reference and my setup is pretty similar to the one here: http://techmind.org/sl/ but our lab does not have an amplifier. I have tested the circuit w/o one (just running...

Homework Statement Hello, I just came across a design problem based on an inverting op amp. The requirement output values are -25G and not greater than 1kOhm output impedance. With inputs 1V p-t-p and 75Ohms input impedance Choosing values for the gain seem fairly easy, but how these values...

Hi all: I am a new member here with my first post. I am an adult learner trying to self-teach RF electronics. I have been working through David Rutledge's Electronics of Radio, while building the NorCal 40A transceiver. I am getting caught up on understanding the Class C RF power amplifier...

Hey guys, need help with a problem here. Sorry for the quality of the image. I understand that above the op-amp, is the active low pass filter. So if I were to figure that out with respect to V2 and Vout, it would just be Vout/Vs = -(Zf/Zs) where Zf = (Rf/(1+jwCfRf)) Zs = Rs But I...

why is the formula of energy in a capacitor E= C x U^2 /2 I understand it mathematically, but I do not understand it if you apply it to a real situation. Is there anyone who can explain that?

< Mentor Note -- thread moved to HH from the technical engineering forums, so no HH Template is shown > Hi, I'm working on a lab project and I have limited instruments/electronics. I am trying to use this op amp to amplify a few uA pulse to a 5 mA pulse. The pulse is passing through a...

< Mentor Note -- thread moved to HH from the technical forums, so no HH Template is shown > https://drive.google.com/file/d/0B3gxtQyBRFkLQU9YdExMaTczTEk/view?usp=docslist_api Here is the copy of the circuit I am try to anaylze. I come up with three amps, but the answer book says .75 amps...

[ mod note: thread title corrected ] Hi All, My first post in the forums, hopefully I'll be able to give out as much help as I receive. I'm currently stuck on an Op Amp gain derivation. Attached is the question and diagram, the derivation I am struggling with is part B. I understand the...

I'm having the worst time ever with a two stage cascode bjt amp. See attached circuit image. In the circuit photo the "In R: 168ohm" is the amps input resistance according to LtSpice. I usually have luck with LtSpice. The circuit shows real measured resistor values. I built a LtSpice version...

Hi,So let's start with this, I don't have a lot of electronics circuits background and not really an idea on how to build an electronic circuit. Ok, now the problem, at my job I am in need of controlling a 24VDC 0,570 Amp pump with a pot, preferably one with a "preset" in it so that the values...

Homework Statement Write output voltage in terms of input voltages for the circuit drawn. I drew the circuit and then feed back loop. Homework Equations Ohms Law V=IR Basic Properties of Op Amps (ideal), voltages are assumed equal at both inputs... The Attempt at a Solution The...

Hello everyone. After googling my eyes out, the only hits I get are about people wondering how much to charge their cell phones. I'm looking for a more academic view point on this. My question is this... Cell Phones, like any device require power. I'd like to find out how many amps or miliamps...

I was watching this video and I have the question, if using a bjt as a diode what is the difference (thermal characteristics) from a regular diode, I ask this because on-semi makes bjt's with diodes in them specifically for class ab amps, is their any benefit besides less thermal lag?

Hi everybody I'm a newbie and working on LM324 to learn Op-Amp. this is my circuit: http://img4.uplood.fr/free/qx3o_20150425_172843.jpg One of the resistors is 217ohm and another 978ohm. then the gain should be 4.50691 as you can see. so far so good. I know this is for ideal Op-Amp. I applied...

Hi all, I realize I'm asking for the world here, but google hasn't been very helpful. I've found a few candidates with some/most of what I need, but wondering if there is some holy grail op amp out there that everyone is using. I'm growing tired of making work-arounds for the LM324's I have...

Hello, Like the title said, how can you tell if it's an inverting or non-inverting op amp just by looking the the schematic like this one. textbook said this is an inverting op amp. I thought whichever input node (+/-) the signal go through dictate the classification of an op amp if it's...

Homework Statement An inverting amplifier with the DC gain of -9 (V/V) is built with an op amp having its DC gain of 105 and corner frequency of 30 rad/s. ▪ Determine the 3-dB frequency of the inverting amplifier. ▪ Sketch the magnitude Bode plot of the voltage transfer function of the...

I would like to know how to design an amplifier similar to the attached circuit with set -3db points, the lower on the order of 10Hz, and the higher on the order of 10kHz. I have designed amplifiers to work with a set gain, but have not dealt with frequency response before. I designed an amp...

Homework Statement Hi Guys, I am trying to solve this question, please look at the attached picture Homework Equations The general equation for a inverting amp is -Rf/R1 * Vin = Vout The Attempt at a Solution Well as the question says the two resistors, R2 and R must be treated as parallel...

20 gauge copper wire is rated for 5 amps. Suppose someone use 18 gauge copper wire and wraps it 60 times around one side of a 1 inch iron ring, with the two ends then connected to a plug. A separate piece of copper wire wraps around the other side 20 times, and goes to a 13.3 Ohm resister. So...

Can Op Amps replace transistors? Can they do everything a transistor does? They can be used as comparators and amplifiers. Will they become obsolete.

I was walking around at work today to find an AC amp Gauge on a DC breaker (1000KW, 250 VDC), Which made me scratch my head if there is any difference between the two gauges for this application? Any idea? Thanks.

guys for the critical frequency for low pass is it the following: 1/2pi* 2.2*10^(-6)*100k?

Homework Statement The op am in the circuit shown is ideal. Calculate the following. a) Ia b) Va c) Vo d) Io Homework Equations I have found three equations one at Vn, Va, and Vo. The Attempt at a Solution The attempt solution is on the attachment. I currently have three equations with four...

Homework Statement Find Vin/Vout Homework Equations Vout = Rf/R1(Vb-Va) ? The Attempt at a Solution I think the answer is the first one. Answer choices: Vin/Vout = -2, Rin = 100 Vin/Vout = -2, Rin = 200 Vin/Vout = -2.5, Rin = 100 Vin/Vout = -2.5, Rin = 200 Vin/Vout = -3, Rin = 100...

Homework Statement Find V0 and i0 of the circuit. Homework Equations KCL The Attempt at a Solution I tried multiple times and never got the right answer. -------------- Hello, I am having trouble solving a problem. I will link a picture of the problem with answers, but it just seems I can't...

Homework Statement I have used words here I'm not sure will explain what I mean accurately. If you're confused, ask, and I'll provide as much context as I can. Given the below circuit a) What are the three properties of an ideal op amp? These properties provides background for two...

Getting confused on understanding how opamp works with zener in Feedback loop. Referring to the ckt here (attached.) (replace diode with 5V zener) Using virtual short, when the input voltage is zero, opamp output is 5V? Basically the opamp sources current into the zener. When the input is -1V...

For the above op amp circuit: Vin= squarewave with 10Vpp and 1kHz. C=0.01uF. Vcc and -Vcc is 15V and -15V. Using the above specs, I calculate R using these equations: Requirement: Create a triangle wave with output voltage Vo to be 10Vpp. This is a gain of 1. Using the above, I find...

Homework Statement Homework Equations The Attempt at a Solution Here is my attempt: http://i.imgur.com/oKjwI8O.png The problem is at the end, I get 0=0. What did I do wrong?

it is my understanding that the input referred noise current (density) can be obtained from Ibias via inoise=sqrt(2*q*Ibias), where q=1.6e-19. on op-amp datasheets, both Ibias and the input referred noise current are both specified. Yet, the value typically shown for the noise current...

The type of op amp I am using is Voltage-to-Current Amp. Under DC voltage input, it works perfectly well, boosting the current of a signal generator (DC mode) up to 250mA with the help of single supply working at 25V. However, when I turn the signal generator in AC mode, hoping to achieve...

Hi guys, I have been working on an automation of a cart. The cart wheels are producing a current of 14 Amps for 5 minutes for every cycle(1.16 Amp hour stored in a battery). while the cart is running there are 2 actuators operating. One actuator uses 10 amps for 5 seconds (only 0.01388...