Op-amp differential amplifier

Started by Patrick Chung in sci.electronics.basics5 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


Signal amplifier works

Started by Uncle Steve in sci.electronics.basics7 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.basics5 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.basics6 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.basics6 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.basics7 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.basics5 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.basics5 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


HF design approach

Started by lerameur in sci.electronics.basics6 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.basics4 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


Amplifier for frequency generator

Started by Goran in sci.electronics.basics7 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.basics12 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.basics12 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....


Building a class A audio amplifier - no audio out

Started by Anonymous in sci.electronics.basics11 years ago 68 replies

I tried to build this Class A amplifier circuit as a learning experience: http://www.techlib.com/electronics/audioamps.html#class-a with the...

I tried to build this Class A amplifier circuit as a learning experience: http://www.techlib.com/electronics/audioamps.html#class-a with the following modifications: 1. I have no MPSW45, so I built a Darlington out of a 2N2222 and TIP31A. 2. 150k resistors: I only had two 100k resistors in my collection. But as long as they're identical, should work...??? 3. speaker: I had only a 10W...


Power output of TBA820M (audio amplifier chip)?

Started by Adam Funk in sci.electronics.basics3 years ago 8 replies

Does anyone know a formula for calculating the power output of the TBA820M audio amplifier IC? The data sheet gives the...

Does anyone know a formula for calculating the power output of the TBA820M audio amplifier IC? The data sheet gives the following examples: supply (V) load (?) output (W) 12 8 2 9 4 1.6 9 8 1.2 6 4 0.75 3.5 4 0.25 but the output isn't consistently proportional to V^2/R (which was my


Linear amp emitter capacitors choice for 20Hz audio app

Started by riccardo manfrin in sci.electronics.basics6 years ago 5 replies

This is self assigned homework, so don't bother if this circuit is impract= ical. I'm just following the basics. With reference to a common...

This is self assigned homework, so don't bother if this circuit is impract= ical. I'm just following the basics. With reference to a common emitter degenerated linear amplifier with partia= l bypassed emitter resistor (figure 2.39 of Arts of Electronics 2nd Ed.), I= 'm trying to figure out the value in Farads for the emitter bypass capacito= r, for an audio amplifier (smallest frequency of...


Tube (valve) amplifier question

Started by Anonymous in sci.electronics.basics5 years ago 8 replies

I have decided to build myself a little tube amplifier so I can hear one and compare it to my modern solid state stuff. Virtually all the kits...

I have decided to build myself a little tube amplifier so I can hear one and compare it to my modern solid state stuff. Virtually all the kits and designs I see online are low wattage output compared to the solid state stuff. I read that part of the reason for this is because a tube amp at maximum output distorts the sound in a way that most folks find agreeable whereas transistor amps disto...


Why use amplifier with adc?

Started by Anonymous in sci.electronics.basics6 years ago 5 replies

I don't know very well how adc works, so i have a question. Most adc have a Vref pin that defines Vin range of adc. Vin range of adc is then...

I don't know very well how adc works, so i have a question. Most adc have a Vref pin that defines Vin range of adc. Vin range of adc is then divider for 2^n (n=resolution) to obtain LSB. If i resize Vref, new Vin range (smaller) is divided for 2^n, so LSB has smaller value.If i have a sensor, why i shoud use amplifier to drive Vin pin of adc?can i resize Vref as i like (or there is a limit)? ...


Darlington pair is two stage current amplifier

Started by Patrick Chung in sci.electronics.basics6 years ago 1 reply

Darlington pair is actually two stage current amplifier. Now, there is new...

Darlington pair is actually two stage current amplifier. Now, there is new tutorial: http://www.cirvirlab.com/index.php/tutorials/107-darlington-pair-or-darlington-transistor-simula tion.html and new online simulation: http://www.cirvirlab.com/simulation/darlington_pair_or_darlington_transistor_online.php


Tube Amp

Started by Dave.H in sci.electronics.basics12 years ago 13 replies

Hi, I'm looking for plans for a 1 or 2 tube low voltage amplifier to go with a regenerative radio. Does not have to be the best, but needs to...

Hi, I'm looking for plans for a 1 or 2 tube low voltage amplifier to go with a regenerative radio. Does not have to be the best, but needs to drive at least 250 mW speaker, preferably 1 watt or more. Thanks, Dave Australia