Op-amp differential amplifier

Started by Patrick Chung in sci.electronics.basics3 years ago

Op-amp differential amplifier has much wider range of input signals comparing to differential amplifier with discrete components. Read...

Op-amp differential amplifier has much wider range of input signals comparing to differential amplifier with discrete components. Read more: http://www.cirvirlab.com/index.php/tutorials/170-op-amp-differential-amplifier-simulation.html and also simulate: http://www.cirvirlab.com/simulation/op-amp-differential-amplifier-online.php


Operational Amplifier basics

Started by Rich in sci.electronics.basics9 years ago 36 replies

I'm trying to understand Op Amps first time round. Are the following statements correct? I've rushed it a bit, so most of it might look...

I'm trying to understand Op Amps first time round. Are the following statements correct? I've rushed it a bit, so most of it might look like nonsense. Please correct or amplify. 1 An Op Amp is basically a DIFFERENTAL amplifier. 2 Unlike a (for want of a better word) a "regular" amplifier, an Op Amp can have two input voltages. 3 When the Op amp is run as a DIFFERENTIAL ampl...


AGC circuit ... threshold amplifier question

Started by MRW in sci.electronics.basics11 years ago 12 replies

I have this circuit: http://tinypic.com/view/?pic=333cv43 I encountered this threshold amplifier circuit. I'm trying to understand how it...

I have this circuit: http://tinypic.com/view/?pic=333cv43 I encountered this threshold amplifier circuit. I'm trying to understand how it works. So far, it seems like it is just a summing amplifier and op amp rectifier combined. I used superposition to find out the voltage at the inverting input (V-), but after looking at the mess of equations I still can't relate the functions of each co...


Signal amplifier works

Started by Uncle Steve in sci.electronics.basics5 years ago 88 replies

... unless there is no signal at the input. I started with some information at the following two...

... unless there is no signal at the input. I started with some information at the following two URLS: http://www.mysticmarvels.com/amplifier.html http://www.talkingelectronics.com/projects/TheTransistorAmplifier/TheTransistorAmplifier-P1.html The first URL goes through the process of building a high-gain amplifier, and it works O.K. with the exception that there is no power. The seco


Differential Amplifier is an input stage of every op-amp

Started by Patrick Chung in sci.electronics.basics3 years ago

Generally, if input stage of an operational amplifier is realized as BJT tr= ansistor differential amplifier, op-amp has smaller slew rate,...

Generally, if input stage of an operational amplifier is realized as BJT tr= ansistor differential amplifier, op-amp has smaller slew rate, smaller volt= age offset and better CMRR. If it's realized as JFET transistor based diffe= rential amplifier, voltage offset is higher, CMRR is smaller but slew rate = is better.=20 Read more: http://www.cirvirlab.com/index.php/tutorials/167-bjt-tran...


Reason for heating caused due to PH2931-135S microwave amplifier ?

Started by Sanoj Singh in sci.electronics.basics4 years ago

I am working on development of RF driver input for Klystron amplifier. As usual, pulsed output of PH2931-135S microwave amplifier (input to...

I am working on development of RF driver input for Klystron amplifier. As usual, pulsed output of PH2931-135S microwave amplifier (input to amplif= ier provided after successive amplifications) on spectrum analyzer with 40 = dB external attenuation produces normal output of around 13dBm on the Spect= rum analyzer without any heating on the attenuator. But, today I am not getting the re...


JFET Common Source Amplifier as counterpart of BJT Common Emitter Amplifier

Started by Patrick Chung in sci.electronics.basics4 years ago

JFET Common Source Amplifier as counterpart of BJT Common Emitter Amplifier has (on average) smaller voltage gain, higher input impedance, higher...

JFET Common Source Amplifier as counterpart of BJT Common Emitter Amplifier has (on average) smaller voltage gain, higher input impedance, higher non-linearity and can operate on higher frequencies. It now can be simulated on: http://www.cirvirlab.com/simulation/jfet_common_source_amplifier_online.php and read on: http://www.cirvirlab.com/index.php/tutorials/126-jfet-common-source-amplifi...


BJT Amplifier Output Votlage Swing

Started by panfilero in sci.electronics.basics5 years ago 12 replies

I'm having a hard time understanding the "negative swing" of a common-emitter amplifier. There is a website called thesignalpath.com where a BJT...

I'm having a hard time understanding the "negative swing" of a common-emitter amplifier. There is a website called thesignalpath.com where a BJT amplifier is described. The set up is a BJT with a collector resistor, an emitter resistor, 2.5V and -2.5V supplies, and we're taking the output off the collector. The BJT has a Vce,sat = 0.2V According to the website maximum Vout = Vdd positive...


Op-amp Summing Amplifier

Started by Patrick Chung in sci.electronics.basics3 years ago

Good feature of op-amp summing amplifier is that there is direct current pa= th provided from every input to the output. For that reasons input...

Good feature of op-amp summing amplifier is that there is direct current pa= th provided from every input to the output. For that reasons input voltage = sources don't need to have current sink capability. Good feature of op-amp non inverting summing amplifier is that output volta= ge is proportional with the sum of the input signals, and with the same sig= n. Bad feature is that there is no ...


Op-amp instrumentation amplifier is initial input stage of EKG and EEG instruments

Started by Patrick Chung in sci.electronics.basics3 years ago

Op-amp instrumentation amplifier is initial input stage of EKG and EEG instruments due to it's high impedance, very high common-mode rejection...

Op-amp instrumentation amplifier is initial input stage of EKG and EEG instruments due to it's high impedance, very high common-mode rejection ratio, and very high voltage gain. Read more: http://www.cirvirlab.com/index.php/tutorials/162-op-amp-instrumentation-amplifier.html and simulate online: http://www.cirvirlab.com/simulation/op-amp-instrumentation-amplifier-online.php


How does one add a 12v trigger to an amplifier...?

Started by bakin in sci.electronics.basics11 years ago 11 replies

I have a high power (2600 watts @ 4ohms min. mono bridge) amplifier that I would very much like to be able to have turn on via the existing 12v...

I have a high power (2600 watts @ 4ohms min. mono bridge) amplifier that I would very much like to be able to have turn on via the existing 12v trigger in my av preamp. Any any suggestions as to the specific component(s) and the cleanest, safest method of installing them would be most appreciated! Thanks!


HF design approach

Started by lerameur in sci.electronics.basics4 years ago 16 replies

Hello to all, I am designing an amplifier for frequencies between 500khz to 5Mhz. (+/-40V= ) a couple of watts. I am a newbie to HF frequencies...

Hello to all, I am designing an amplifier for frequencies between 500khz to 5Mhz. (+/-40V= ) a couple of watts. I am a newbie to HF frequencies , but I would like to know what is the best= amplifier technique for these frequencies.=20 At first I wanted a pushed and pull mosfet driven by a mosfet driver, but t= he more I am looking the more i'm confused. I've seen some expensive specia= liz...


AMP, ADC, Transistor Questions!

Started by Anonymous in sci.electronics.basics2 years ago

Hello everyone. I am picking up on a project someone else worked and and I wanted to see if anyone had some ideas on a amplifier and ADC...

Hello everyone. I am picking up on a project someone else worked and and I wanted to see if anyone had some ideas on a amplifier and ADC connection that is being made in their schematic: 1.) See the schematic here: http://i1228.photobucket.com/albums/ee460/MrBlueCalifornia/qustion_zps3ck8j17m.jpg 2.) I am using a differenctial amplifier to measure a signal (U4 and U5 of


Op Amp virtual ground

Started by mahak in sci.electronics.basics10 years ago 14 replies

Hi, This is mahak. can anybody tell me what is virtual ground concept.I refer to Micro electronics by Sedra & SMith. There it says Virtual...

Hi, This is mahak. can anybody tell me what is virtual ground concept.I refer to Micro electronics by Sedra & SMith. There it says Virtual Groung is because of infinite gain of amplifier. But if that is the case then it should be there for both inverting and non inverting amplifier. Please clarify.


Operational amplifier

Started by Rocky3 in sci.electronics.basics10 years ago 5 replies

Hello! I'm getting started with the study of operational amplifier. Fist of all, do you know any site which could explain clearly this matter?...

Hello! I'm getting started with the study of operational amplifier. Fist of all, do you know any site which could explain clearly this matter? Could you write some link? In particular, I can't understand the reason why a saturation occurs when the output signal is connected to the + terminal. The output is alway connected to che other terminal, the - one. Why? Can you help me? Thank you a...


Low cost, small size DIP Instrumentation amplifier IC

Started by chetanthegreat in sci.electronics.basics10 years ago 8 replies

Hello folks, I am facing a bit of trouble regarding the signal conditioning part. The standard 3 Opamp instrumentation...

Hello folks, I am facing a bit of trouble regarding the signal conditioning part. The standard 3 Opamp instrumentation amplifier using TL084 I am planning to inculcate becomes very bulky considering all the resisters involved for gain adjustment and similar tasks. There are 6 of these circuits on the entire board, thus resulting in unusually large PCB for the project. ...


Distortion In LM386 Amplifier

Started by Dave.H in sci.electronics.basics9 years ago 15 replies

I have an amplifier in my workshop, for listening to tunes from my iPod, but if I turn it up louder then whisper level, it distorts, pretty bad....

I have an amplifier in my workshop, for listening to tunes from my iPod, but if I turn it up louder then whisper level, it distorts, pretty bad. I've been going nuts trying to figure it out, even tried many different speakers, from 1/2 watt to 20 watt ratings, and swapped out the LM386 chip. I have another one of these kits, used for an iPod amp around the house played through a 1 watt 2 inc...


Amplifier for frequency generator

Started by Goran in sci.electronics.basics4 years ago 14 replies

Hi. Im making one simple mcu based device that will work as electronic repellent. Nothing special. Only difference is that i want to check...

Hi. Im making one simple mcu based device that will work as electronic repellent. Nothing special. Only difference is that i want to check other frequency ranges and to do so, i have to connect my device to function generator ( 0 - 4 MHZ ). Does someone knows how to build amplifier for this function generator ?


How can I measure the output impedance of an operational amplifier ?

Started by Martin Sigwald in sci.electronics.basics10 years ago 15 replies

I need to physically measure the output impedance of an operational amplifier (LM741), working as an inverter and with a capacitor as load. Any...

I need to physically measure the output impedance of an operational amplifier (LM741), working as an inverter and with a capacitor as load. Any ideas on how to do this? Impedance analyzer is out of the question. Thanx in advance.


lockin amplifier question

Started by jeremy in sci.electronics.basics10 years ago 5 replies

hi i am using a lockin amplifier for the 1st time other than a canned college lab demo i have a 5mV signal from a strain gage that is driven...

hi i am using a lockin amplifier for the 1st time other than a canned college lab demo i have a 5mV signal from a strain gage that is driven with 10Vpp at 1kHz or whatever i choose. the 5mV is increased to 5.01mV when i add some weight to the arm the gage is weighing. i wanted to increase sensitivity of this reading with the LIA since there is noise in the next digit, i.e. i read 5....