An amplifier can be used to adapt the range of the signal to a requirement, to make it more robust for transmission, or to satisfy interface requirement (like input/output impedance)

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27 views

Two amplifiers in single speaker with different frequency power

I have two amplifiers using LM386. One of them I plan to use for normal amplifier and the second one I want it to be a low pass amplifier/bass amplifier and both of them will be connected to same ...
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1answer
71 views

MOSFET Amplifier?

I'm trying to create an amplifier circuit using a n channel MOSFET and I can't seem to get the results I'm looking for. I'm trying to amplify an AC signal up to the +/- Vcc but I keep getting strange ...
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2answers
36 views

Amplifier damage caused by failed power supply capacitors [on hold]

MY QUESTION IS THIS: Would failed power supply caps cause peripheral damage to the amp, preamp or control circuits ? Supposedly there is "protection" for "DC offset, over current and over heat" I ...
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2answers
95 views

Amplify DC Voltage to be used like supply to 2Km

Is there something to help me to reach this goal? I want to turn on a device away from the voltage source to 2 Kilometers, my device operates at 24VDC or 48VDC / 35W. I need to know how is possible ...
2
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3answers
121 views

Turn TTL output of logic IC into output capable of driving 50 ohm devices

I want to provide front-panel trigger signals with the microcontroller inside my device. The trigger signal will be fed via a 50 ohm coax cable to another device with a 50 ohm input. A direct ...
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2answers
85 views

Help to design an amplifier

I need help designing an amplifier that is capable of providing 1 W to an 8 Ohm speaker. I have 3.3 V, 5 V or 18 V supply available to power it. I also have only one power supply available that has ...
0
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2answers
34 views

looking for an amplifier for an ultrasonic frequencys transducer [on hold]

I'm trying to create a narrow sound beam using the non-linear propagation of ultra sonic waves in the air. While doing so I need to connect my DSP unit and my ultra sonic transducer through an ...
0
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3answers
53 views

How to measure the resistance of digital potentiometer AD5241 in circuit when power on

I have designed a transimpedance amplifier including a digital potentiometer AD5241. The circuit is showed below. I want to test the AD5241 to make sure it works as designed. simulate this ...
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1answer
82 views

Extremely low output from amplifier

I am unsure what is wrong with my amplifier / microphone coupling. I have read many of the posts on stackexchange including the following: ...
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2answers
88 views

How to calculate battery life with a given load?

I am not very good at electricity things so any help anyone could give me would be fantastic. Here goes: I have a battery (for power tools); it is 18v and 1500 mAh (imagine DC). I'm trying to get it ...
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2answers
63 views

Amplifier design

I am having trouble calculating values for this audio amplifier. Input comes from AVR PWM operating at 44.1 kHz with high being at 3.3V. The speaker is 8 Ohm and speced for 1 Watt. First two ...
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1answer
46 views

Can an amplifier deliver a higher power for a short burst as opposed to continuously using the same circuit

I am struggling to understand the fundamental power requirements for an amplifier. If I want to deliver 56 V rms to a 7.5 Ohm load I can use P = V^2/R and find that I need 418 W rms. Requiring a ...
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2answers
157 views

How to characterize SNR for an amplifier with extreme low input signal?

Often that the OPAMP has an internal noise of 1uV. If I have an extreme high gain of 10000, the noise will be amplified up to 0.01V. Then, when I input a very low input signal of 10uV, after amplify ...
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1answer
41 views

Modeling diode connected transistor in differential amplifier

I have question about the analysis of common-mode gain of BTJ differential amplifier with active load on the Sedra Smith book. In this book, the differential-mode gain \$Ad\$ is derived based on the ...
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1answer
40 views

Biopotential measurement circuit

I have read the following paper (the link at the end), and I have not understand the schematic, which is included in the picture below. To be more specific, there is a feedback integrator, denoted by ...
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2answers
76 views

Why can't I swap a TL071 with a 741?

I constructed this circuit as shown for use as a simple headphone amplifier. I was so happy with myself that I made a second one for stereo, as well as using a 3915 to make a very simple volume ...
2
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1answer
39 views

Differential amplifier with active load Sedra Smith

I'm studing differential amplifiers on Sedra Smith book, and I have come across the following circuit. My question is: how can NMOS transistor \$Q_2\$ have a current \$g_{m2}\cdot v_{id}/2\$ if the ...
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2answers
54 views

Looking for OP-Amp with good rail to rail performance, 5V to 0V [closed]

There are thousands of OP-Amps on Farnell's website, so I thought asking the stack-exchange community might be a good idea. I am looking for an OP-Amp for use in my project. I currently have an ...
2
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2answers
93 views

Help understanding PIR amplifier analog circuit

I found a PIR amplifier circuit and would like to understand better how/why it works. The purpose is mostly to learn more about analog electronics. I found the following circuit here: PIR motion ...
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1answer
40 views

amplifier PAM8403 separated ground on the output..?

Ok, this thing PAM 8403 has separated gnd. out...for left and right.so how do I connect my headphones which have 1 ground for booth channels...? I haven,t tried it yet but I don,t know if it will ...
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3answers
198 views

How to set up an experiement to measure SNR for an EEG amplifier?

I have built an EEG amplifier with gain of 2000 and bandwith at 1~40Hz. I use an Instrument Amplifier for pre-Amp and a non-inverting opamp as post-amp and finally bandlimit at 40Hz using a 4th-order ...
2
votes
3answers
90 views

Why does my output stage rectify when I use a preceding stage?

I've been working my darnedest over the past few weeks learning more and more about amplifiers, BJTs and various topologies. As I go through Art of Electronics, I try out everything mentioned in at ...
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1answer
37 views

How boost a DVB-C signal [closed]

I receive a DVB-C signal from my broadcast TV provider, and I use coaxial cables and some splitters to connect my three televisions to the coaxial wall-socket. Unfortunately I have problems to ...
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2answers
87 views

AC amplifier with fixed output range?

Lets say I have a sine frequency sweeping circuit (1kHz-10MHz) that goes down in magnitude, from say 3V to ...
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0answers
38 views

Crystal Oscillator Output Amplification

I have a HCMOS Crystal Oscillator at 50 Mhz (DataSheet). With an ac coupling and pi network I generate a sine wave with 50 ohm output impedance. In standart bjt oscillator circuits, one need to make ...
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2answers
180 views

How is the gain controlled in a class B/AB amplifier?

I have tried simulating a simple class B amplifier, and I can't seem to get any gain (in fact, due to the crossover distortion, the gain is less than 1) For example, in this diagram the resistors ...
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2answers
26 views

connecting an enamled headphone jack to a bread board

I am trying to make an audio amplifier on a bread board. I have a headphone jack with enamled wire and I need to connect it to the breadboard using conductive wire. I have been unsuccessful, does ...
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1answer
94 views

AN7149N -based power amp usage

I have assembled AN7149N-based power amplifier according to the datasheet, but it shows no signs of life. The only changes I made were 2,7 ohm resistor instead on 2,2 ohm one, and 1000uF capacitor ...
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1answer
50 views

instrumentation amplifier output noise

I have a low level DC signal from a thermopile sensor of 0-9.1mV with 7uV increment. I feed this to an INA114 instrumentation amplifier with gain of 550 to get 0-5V output. I tried introducing RF ...
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votes
2answers
195 views

How can I simulate a bridged output of a speaker at 8 ohms?

Following on from my previous post on a single 5V rail amplifier, I'm trying to simulate a bridged output op amp set up to drive an 8 0hm load. One of the solutions was: Use a bridge output. This ...
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2answers
74 views

How to play a microphone out of a speaker?

So I have a small amplifier that plugs into a 12V source and a standard 3.5mm headphone jack and plays pretty good sound to a 8ohm speaker. I am wondering if I can connect the 3.5mm headphone jack to ...
0
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1answer
54 views

Ground separation

I'm designing a small PCB for low-level light detection. It contains an Avalanche Photodiode (APD), the DC regulator required for proper biasing (from 5V to ~65V) and a transimpedance amplifier. My ...
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1answer
62 views

Operational Amplifier Voltage Stabilization

I am wondering how an Operational amplifier stabilizes voltage ? Is it by negative feedback, if yes, then how ?
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2answers
90 views

Using audio amplifier speaker output to drive an electromagnet

My first time here as a poster so forgive me if I make a misstep... I am building a coil (22swg enameled copper wire, about 500 ft), some 4in inner diameter of the bobbin, 1" wide, will have ~ 450 ...
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3answers
39 views

Summing Amplifier Zero Input Current/Voltage?

I have 2 questions related to a summing amplifier: Why is the voltage at the inverting terminal of the input equal to zero? Why is the current at the inverting terminal of the input equal to zero?
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1answer
59 views

Current Mirror Sense Amplifier

I am unable to understand the working of the below circuit and how it act as amplifier. Enable the SAEN signal i.e. turning it high. Let us assume that we get DL as 1 and DLB as 0. Actually it will ...
2
votes
1answer
136 views

Sense Amplifiers in SRAM

The basic 6T structure used for storing data is same as one used in "Positive Feedback Differential Voltage Sense Amplifier", then how come while the data is stored in SRAM memory cell it doesn't get ...
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votes
3answers
78 views

How to design a circuit using inverting op-amp when input-output relation equation is given?

Like this: $$V_0 = 5V_1 - 3V_2 + \frac{V_3 + V_4}{2} - V_5$$ I know about the transfer function but I am not able to make circuits from these relation and I am not able to find it in any book.
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1answer
71 views

Level Shifting & Amplification

I am trying to design a crane load (Weight) measuring unit using motor current measurement technique. For some reasons we can't use load cells here. Part of schematic I have drawn here An air core ...
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1answer
76 views

LM3886 full amp reduces hi freqs

I've bought this kit and successfully assembled it. I use 23.4-0.23.4 V power source and two ELZET 10000uF caps. So, after I connected my speakers (by the way it is Amphithon (Амфитон) 25АС-027 4 ...
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2answers
96 views

How can I extend the ammeter wires to my shunt?

Is it possible for me to locate my ammeter and shunt a few meters away from each other (more than intended by original wiring)? The extra wiring obviously has a resistance and provokes a false ...
0
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2answers
104 views

Can I amplify high frequency signal?

I have found this awesome Raspberry PI FM transmitter project. It uses RPi GPIO pin to simulate FM signal. After some filtering to smoothen it, this could act like a real transmitter. But at this ...
4
votes
3answers
169 views

How to know whether the bandpass filter is stable

I am designing a bandpass filter using MFB. However, I do not know whether my filter is stable or not. Can anyone give me some criteria or methods to evaluate the stability of the filter design?(still ...
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2answers
44 views

Optimal headphone impedance

Looking at the data sheet of the MAX4410 headphone driver, lower impedance headphones will get more power. Is this true in general for laptop headphone drivers? especially with regards to 8-32 ohm ...
0
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1answer
56 views

Output stage amplifier bias

I have some problems with bias output stages. For example in circuit below: BC547 (VAS stage) collector voltage is about 11 volts and I cannot directly connect it to the base transistor on the next ...
0
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1answer
94 views

Small but powerful speakers [closed]

Why are powerful speakers like above 20w or 80w not small? I have never seen enough in the market which are under 3 inch but of 80W. The opposite is also true, some big speakers are of low wattage. ...
1
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1answer
78 views

Line-out: why is there no impendance issue when plugging an amp rather than headphones?

Given that the input of an amplifier has very high impedance, while headphones have very low one, why can I plug either one or the other on the audio-out plug of my computer? Even with a degree on ...
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0answers
43 views

How to find bias so that OP amp output range is max?

I have a question about (d): I just know that the maximum output may be \$V_{BP2}+|V_{ov7}|\$ and that the minimum may be \$V_{BN2}-V_{ov9}\$. Can anyone help me? By the way, I want to check the ...
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1answer
47 views

adding limiter to reduce distortion in audio amp

I got this schematic from adafruit. But at high volumes, it exhibits distortion. A guy from Maxim Integrated referred to include a diode-resistor network(BAV99 and R-100 Ohm) b/w C22/C23 and R8/R9(to ...
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2answers
99 views

MOSFET amplifier

I found the following problem in the Rashid book of microelectronic circuits. I am looking to solve it but I don't even know where to start. How can I solve everything? What results do you get so I ...