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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35 views

Difference amplifier schematic

I am trying to get this difference amplifier working, but it doesn't seem to be outputting what I want it to output. $$ V_1 = V_{in}\qquad V_2 = -0.5\mathrm{V}\qquad R_f=R_i, \quad A=1 $$ I want ...
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189 views

Anti-aliasing filter closer to amp or ADC?

I'm designing a board with several amplified analog signals being fed into the internal ADC of a PIC DSP (dsPIC33FJ256GP710). Because of the board size/shape restraints, the analog buffers can't sit ...
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2answers
59 views

Internal resistance of signal source

It was told me that a signal sent to the circuit can be rapresented by \$V_{sig}\$ and \$R_{sig}\$, where \$R_{sig}\$ is the internal resistance of signal source. Now, let's consider that we have a ...
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95 views

Would anyone explain this circuit? [duplicate]

I know that the transistor works as an amplifier but I can not understand why it is connected this way. I'm a beginner in electronics and I just want an explanation for this circuit (especially the ...
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0answers
48 views

Why left speaker dies out? [on hold]

I have read many complains and even faced the problem myself , that the left speaker of any device dies first. Be it headphone, Speakers or Earphone. Is this problem due to some issue in the amplifier ...
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1answer
81 views

How to figure out battery life of audio amplifier?

I have a design of an audio amplifier. It has some special features but basically it takes in an audio signal does some filtering, and amplifies it through a class D amplifier chip. The chip says it ...
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1answer
82 views

Safest way to make a high-voltage switch

First of all, I've dabbled in electronics on and off over the years. I have no formal training. I'm designing a vacuum tube guitar amplifier (seems like everyone is these days). I want to add a ...
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53 views

Design s small signal common emitter BJT Amplifier circuit? [on hold]

Requirements for the circuit are... 1.voltage gain of 50. 2.minimum input resistance 95k. 3.output resistance of less than 185ohm. 4.maximum unclipped output of 5v 5.9v DC power supply for the whole ...
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1answer
77 views

Two-stage amplifier

This is my first time designing a circuit by myself :) The input of this circuit is the output jack of my MP3 Player. The output of this circuit is 4-Ohm loud speaker (sometimes I connect 8-Ohm ...
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6 views

Impedance Matching for Amplifier Output [duplicate]

0 down vote favorite I needed some basic advice about impedance matching. I have an RF amplifier with 50 ohm output impedance, capable of generating 400W output power at 500kHz. I am trying to ...
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4answers
104 views

Impedance matching for amplifier output

I needed some basic advice about impedance matching. I have an RF amplifier with 50 ohm output impedance, capable of generating 400W output power at 500kHz. I am trying to deliver this to a 12 ohm ...
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2answers
72 views

How to choose a transistor for amplification

I've been trying to find information on choosing an NPN transistor but everything I've found seems to apply to saturated transistors only. I'm basically trying to amplify the current given from a 3mm ...
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3answers
50 views

Question about common emitter configuration?

The configuration of the common emitter amplifier is one resistor at the emitter, on resistor at the collector, two bias resistors at the base as shown in this picture : I saw this new ...
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1answer
41 views

Which output and input to be used?

I'm planning to generate a signal and amplify it. I couldn't find the manuals but I have the detailed pics. The function generator: And the amplifier is here My question is: 1) The function ...
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1answer
101 views

Would you help me understand this simple circuit?

I have three questions: Is it common emitter or common collector (emitter follower) or something else? How do you recognize it? What is the function/usage of R1 and C1? Are they for biasing the ...
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3answers
67 views

Does it matter the order of amplification and rms squaring?

If in a circuit a signal is first amplified and then its rms value is found, would we get the same result if first the signal is rms found and then amplified?
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21 views

Amplifier connection from a signal generator to a speaker [closed]

Have an old amplifier and cannot find any manuals. I found the following link with photos from all sides: ...
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2answers
84 views

How can I Improve the quality of an amplifier?

I amplify using LM358 Op-amp and 2 resistors. I played a song on my mobile. The output of the Mobile is the input of my circuit. The output of my circuit is connected to 8 ohm speaker. I hear ...
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2answers
62 views

Input voltage for LM4862 audio amplifier

I just started working on an embedded side project that requires me to pump .wav files through headphones. My main microcontroller is a PIC32, and my audio amplifier is an LM4862. For the DAC ...
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1answer
50 views

BJT Topologies - Design Principles at RF

Here are some rules of thumb I've learned when designing single-transistor BJT amplifiers: High input impedance is good Low output impedance is good Biasing resistors should draw ~10% of the ...
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1answer
48 views

Powering a load with specified maximum current of 300mA. Is it safe to use a matching voltage power supply with a higher current rating? [duplicate]

I just bought a guitar amp that can be powered by a 9v battery or a 9v power supply. The instructions that came with the amp specify that the power supply should deliver 300mA maximum. As far as I ...
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2answers
134 views

how to choose resistors' value for common emitter amplifier? [closed]

I want to choose the best values of R1 , R2 , R3 and R4 to get the maximum gain (high performance). I design the circuits practically, so I don't need to do a lot of calculations. I want the ...
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1answer
31 views

Class D inductor current calculation

How do I calculate the required inductor current (RMS, saturation) for a class D amplifier? Assuming the following configuration: Speaker impedance (Z) = 4 ohms Power output (P) = 400W ...
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3answers
148 views

Control voltage using transistor

I know nothing about transistors except they can be used as simple amplifiers. I do not know which one to use for my project. A port from arduino would give me volts ranging 0V-5V. I have an external ...
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1answer
40 views

Questions about the front end design of amplifier circuit

Question 1: Recently, i'm working on a design which needs to design an INA front end. The most used circuit like this (please omit the component values): You see, the two 10M resistors which ...
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2answers
51 views

Class D amplifier output filter calculation

I want to build a simple amplifier with TI's TPA3116D2, which is "filterless" Class-D amplifier. This device can be run with a traditional LC filter at the output, or, if the speaker wires are short, ...
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1answer
27 views

Convert A weighted voltage output into sound pressure

I have designed an A weighting network circuit. but i cant understand how to convert it's voltage output in to corresponding sound pressure level in dB. So How can I convert these voltage readings ...
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1answer
67 views

Can PGA be cascaded to amplify small signal?

I need amplify small 50Hz AC signal. The range is from sub mV to hunderds of mV. Can I use multiple cascaded PGAs? Something like: signal_source => PGA205 => PGA204 => PGA204....,
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1answer
61 views

What does the feedback capacitor do in Right-Leg-Driver?

It so happens I have seen some people mention about connect a feedback capacitor across the opamp for RLD would improve something better. Can someone capable to explain about the use of the ...
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1answer
66 views

Amplifier stopped working completely after changing op-amp

After replacing op-amp given in the picture with LM386L the amplifier pretty much stopped working entirely. There is only a faint sound on the output - as if the gain was way below 1. Given the ...
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1answer
86 views

What kind of amplifier to use?

I'm driving an LED from the output of an optocoupler. Example, I'm trying to find surface errors on a sheet. When the sheet is flat the average output voltage is around 2.45V (based on the circuitry I ...
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1answer
85 views

How to amplify the signal of a TCRT5000 phototransistor

I'm trying to read the IR signal from my Itron C1S Power meter. It has an emitter that lights up for 10 ms every Wh of consumption. This question is based on my prior question: Use a photoresistor ...
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1answer
61 views

What is the current gain of this op-amp circuit?

I just happened to see this circuit in some lecture slides and I thought I could solve it. Unfortunately, I've been trying to check my result with an ideal simulation in LTspice and all my attempts ...
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1answer
50 views

Help me figure out this 12AX7 Tube Preamp mess

A few years ago I built a Tube guitar amp / pedal / preamp with a 12ax7 tube (and some other pin compatible tubes). I don't remember what schematic I used to make it and I wasn't skilled with ...
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1answer
56 views

Load cell without In-amp

I have a 0-1kg load cell with 4 wires: Excitation + and -, and Signal + and -. I haven't had any problems wiring them up correctly without amplification, and my voltmeter shows me a 1 mV difference ...
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1answer
46 views

FM Transmitter Amplifier — Maximum output power with non-customized parts?

I would like to build an FM transmitter on my own and I found a nice circuit that acts as a USB sound card to transmit low power FM signals. http://tipok.org.ua/node/35 My plan is to add another ...
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2answers
252 views

Common Emitter not amplifying

I am trying to make a 27 MHz carrier wave transmitter from a crystal oscillator and a secondary amplifier. Thi is the complete circuit: simulate this circuit – Schematic created using ...
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3answers
57 views

Would having no power supply but a large input signal damage the amplifier?

I am now learning about the power sequence of the circuit. And wonder that as every amplifier has its own limited input voltage (for example: ADA4004's input limit is V− < VIN < V+), would the ...
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3answers
116 views

Output impedance refers to open circuit o/p impedance or short circuit o/p impedance?

When we specify output impedance of a two port network, does it imply open circuit output impedance or short circuit output impedance? Wikipedia: output impedance ; Wikipedia: two-port network g22 ...
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2answers
94 views

Using a DC voltage as the base for a transistor to amplify AC Voltage

I'm a little new to electronics, particularly transistors, so I don't know a lot of the different types and inner-workings of them. I have a diagram which, hopefully, will gradually increase the ...
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1answer
33 views

Input to amplifier with LPF not working

I am trying to build a pink noise machine to use at work. See schematic below. If I connect the output from the MM5837N (noise generator), directly to the amp circuit. It works fine, and is nice ...
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1answer
43 views

Problems with OpAmp based amplifier simulation

I'm trying to simulate a simple amplifier for an electret microphone, but having problems regarding the output level and virtual ground. The circuit in Multisim is as follows: What I'm having ...
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2answers
57 views

Trade offs between adc range and amplifier gain design

Edited on 15th,Aug Tradoffs between ADC range and amplifier gain If I want to measure a very small signal with 16 bit ADCs,say 10kHz sine waves with amplitude ranging from 0 to 1uV, I have to ...
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2answers
83 views

Does the VU meter on audio amplifiers measure the input or output level?

Does the VU meter on commercial audio amplifiers measure the level of the input signal or the level of the amplified signal?
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1answer
50 views

I2S based Codec

I want to drive a small mono-speaker that helps in announcing few messages. I am just learning and doing it now. My board is based on I.MX6, I am interfacing it to a an audio codec TLV320AIC32 via ...
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3answers
117 views

How do I amplify voltage from a DAC?

How do I do I output an analog signal from 0V - 10.67V using a DAC and provide a Vcc of 5Vdc that can supply at least 3.5 Amps to the rest of my circuit? I am trying to make a circuit that outputs a ...
4
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1answer
177 views

Headphone output: DC Bias?

Need some electrical advice, as my days of my Electrical Engineering degree are well behind me... I have 4 PMR446 radios ("walkie-talkies"). They work great, but when using an earpiece, every-time ...
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1answer
37 views

How to solve transfer function of a bandpass filter with Butterworth approximation?

How can I calculate the transfer function of this bandpass filter characteristic with Butterworth approximation? \$A_{max}\$ = 0,9 dB \$A_{min}\$ = 6,5 dB \$\omega\$3 = 100 \$\omega\$1 = 300 ...
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1answer
70 views

Fire pit dancing to music — increasing the voltage from a subwoofer out

I am creating a propane "regulator" which allows the user to connect a speaker output to control a valve (0-10V max:0.185A) which opens more with higher voltage. Here's a video of it operating ...
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1answer
57 views

Space Vector Modulation

Im looking to learn more about this topic so that I can implement it in an amplifier design. I've read around and understand most of the math behind it, but I'm still a little fuzzy on how to ...