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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32 views

How can I measure the power output of RF Power amplifier

I have a power amp (50 Ohm) that is connected to a load of Z=55e(-0.77i), by standard coaxial cable with 50 ohm BNC connector. The wiring is short, less than 1 metre. The voltage reading from the RF ...
3
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4answers
149 views

Vacuum tubes textbook

"The art of Electronics" is often adviced as a basic, non-academic textbook for beginners and for all the enthusiasts. It is referenced also in several questions like this one. But in the Table of ...
2
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1answer
114 views
+250

Discrete opamp design

I am working on modifying SG acoustics SGA-SOA-2 opamp (http://www.sg-acoustics.ch/analogue_audio/discrete_opamps/). The goal is to make it work on 32ohm headphones load, and use more common ...
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0answers
44 views

13.5 MHz amplifier 20 W

I need to design an amplifier that takes a 13.5 MHz signal (10 mW, 1 Vpp) and amplifies it to 20 W for a coil. I'm thinking I'll use an op-amp to drive a Mosfet, but I don't know much about designing ...
0
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1answer
33 views

Single transistor Amplifier analysis (Q point values)

Could somebody please check to see if what I have done is right? I posted a similar question a few days ago and someone said V(CE) is equal to V(CC)/2. Is it ok to do this? So I got V(CEQ) = 6V and ...
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3answers
54 views

Single Transistor Amplifier Analysis

Shown below is the question which is doing my head in. I'm on part (ii) and I'm struggling. It's only 2 marks so it must be a simple answer but I cant solve what Vceq is. Below the question is what ...
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1answer
54 views

Is it possible to use a dual rail power system to power op-amp which is designed for a single supply?

I am designing an amplifier circuit using the LM386 amplifier. I am using the schematic below as a guide. I have access to 3 pins: +5V, virtualGND and -5V. Is it possible to power this amplifier using ...
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2answers
35 views

Simple amplifier circuit for a synth chip

I have bought a SID chip with the intention to build a simple synth. I'm pretty confident with the digital aspects of using it but I'm not very familiar with the analog ones and specifically I would ...
0
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1answer
53 views

Strange frequency of audio output voltage

For a school science experiment, we have stripped an audio cable and hooked the right channel and ground wires up to a voltage graphing device. The audio cable is plugged into the audio output of our ...
1
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1answer
56 views

Need help designing headphone amplifier circuit

I have to design a headphone amplifier circuit. We are told the impedance of the headphones and the minimum voltage they require and also the voltage source. After researching I have found that the ...
0
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2answers
74 views

Summing two voltages without the use of an operational amplifier?

Is there a way of summing two voltages without the use of an operational amplifier? http://www.electronicspoint.com/threads/add-two-voltages-without-the-use-of-a-opamp.242875/ This article said to use ...
0
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0answers
32 views

How to choose output network RC and RL values of an audio amplifier?

With "output network" I'm referring to that RC series circuit connected from the amplifier output to the ground, and the following RL parallel circuit connected in series with the output. I know what ...
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0answers
41 views

Car amp - Loose Earth [closed]

Below is an image of a car amp I'm trying to restore. I have a loose earth wire and am not sure where it was fastened before. Is it common for an earth like the one shown to be fixed to the case? Say ...
2
votes
1answer
43 views

Is BJT amplifier a viable option if the design needs to be replicated without calibration?

||Sorry for messing this up the first time. This is my first post ever in a technical forum. Need to pick up the ways of the crowd. Thanks for all the feedback and help. Well appreciated|| I intend ...
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2answers
96 views

Audio amplifier controlling volume with Arduino?

I'm building a project that outputs audio via an Arduino to a powered computer speaker. This audio signal comes from a sine-wave-table lookup that I step through at various frequencies, setting a PWM ...
0
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0answers
33 views

100m Bluetooth Range

Is it possible to get 100m of Bluetooth range with a meandering antenna and 10dBm transmit power? I'm using a CSR chip and it's interally limited to 10dBm and won't allow 20dBm. If it's not ...
0
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1answer
30 views

2 Questions regarding XTR105

The questions that I'm about to ask will likely "paint very broad a stroke" and open-ended, so feel freed to give whatever that may come to your mind, in full detail or with some rough ideas. XTR105 ...
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0answers
72 views

Trouble with decoupling capacitor on simple low-pass circuit

I'm trying to filter all signals above ~350Hz from an electret condenser microphone's output and amplify what's left for analog input / DSP. I'm a beginner, so I cobbled together the design from a few ...
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1answer
47 views

Speaker and Headphones on Microcomputer

I am designing a circuit for the CHIP Microcomputer and I want to enable audio output using headphones OR a speaker. For clarification, when the user plugs in headphones, I want the speakers to be ...
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0answers
72 views

How Transistor works as an amplifier in this circuit?

I want to build a circuit to use transistor as an amplifier. I searched on google and found this circuit which uses transistor to amplify the audio. Is it only the transistor or any IC which is doing ...
0
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0answers
33 views

Mos amplifier mismatch

There is a question on my textbook..Analyze in a detailed manner the effects of the mismatch in the differential amplifier MOS.Which one has a dominating effect according to you and why? I know how ...
0
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2answers
81 views

Resistor values for getting a gain of 10.86 in instrumentation amplifier

I am just stuck with a problem. Here using an instrumentation circuit (see image below). I want to know the exact value of resistors for a gain of 10.86. I have calculated and found some values (25K ...
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1answer
54 views

Can an amplifier charge itself?

My friend asked me this question and I had no answer. Here is what is proposed : An amplifier is fed a current of, say 1 Ampere. Let's say it amplifies it to 100 Amperes. The output is so designed ...
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2answers
53 views

When should I be considering an operational transconductance amplifier (OTA)?

I found a few questions roughly related to this: How is a transconductance amplifier used to measure current? Operational Transconductance Amplifier Input Configurations Dead or alive: Operational ...
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0answers
53 views

Can someone explain this Arduino theremin circuit to me?

I'm going to try building an Arduino theremin via the instructions here, but I'm a bit nervous because there's a lot I don't understand about the circuit. For reference, I have a degree in CS and am a ...
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1answer
112 views

HEMT/PHEMT transistor circuit design- need manual/book

I have to design a microwave amplifier in the frequency range of 0-15GHz. To this end, I need to be able to design circuits with HEMT/PHEMT transistors. Is there a comprehensible manual that teaches ...
1
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1answer
81 views

7W IC amplifier

I have a 7W Audio Amplifier IC Module. It's instruction says power input should be 12~16 Volts. The audio source should be connected to "IN" and "G". Output should be a 7W Speaker to "SPK". In lab, ...
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1answer
59 views

2.4GHz signal through 900MHz amplifier?

Nobbie question, but I was wondering: if I were to generate 2400MHz signal in VCO and put it through, let's say 900MHz RF amplifier, will the output signal be 900MHz? Or would this experiment fry the ...
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1answer
60 views

40kHz signal amplifier with ua741

I am trying make an amplifier with UA741 to amplify signal from ultrasonic sensor. I tested this circuit with a sinusoidal signal from function generator but this only raised the signal level adding ...
2
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2answers
120 views

Is the current gain value constant for a single BJT ?

hfe of a npn bjt transistor is given by collector current / base current so to calculate hfe you need to know the collector current and base current (which can be set using resistors) . I have to ask ...
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1answer
57 views

Actively biased JFET Amplifier

simulate this circuit – Schematic created using CircuitLab Its just the basic diagram (the actual circuit is a low noise amplifier at 5.5GHz).It does work very correctly.In this circuit ...
0
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1answer
44 views

pseudo differential input of amplifier

The Signal Recovery Model 5184 is an ultra low noise preamplifier. The product description says ... and incorporates a special pseudodifferential input stage that can be floated to give the ...
0
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1answer
50 views

Question about output current

I've got huge three-phase transformer, primaries are connected in Y configuration, secondaries in Delta, then goes to 6 diode bridge rectifier. Output is about 200 amp 52 VDC. In short, how many ohm ...
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3answers
160 views

How exactly does a transistor amplify the input current in CE configuration

I have gone through tons of forum discussions and videos and books but they all explain in terms of mathematical equations that factor the input by a 'larger than 1' number. What happens physically ...
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2answers
48 views

Hi-Fi Stereo Amplifier gain regulation with potentiometer

This is my first question ever so please don't kill me :) I have built a stereo hi-fi (end) amplifier 2x10W based on a IC TDA2009. I have bought it as a construction (learning) kit ready to solder. ...
1
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1answer
43 views

Repairing/understanding this guitar amp master stage

The failure For the past few months I've been looking to repair my old-style Roland Cube 60 watt amp after it had been left out on a cold night. The point at which it failed was when I turned it on ...
0
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0answers
16 views

Measuring gains on 2 channel amplifier

Let's say I had an input stereo signal and two black boxes that were each going to amplify a channel on a stereo speaker signal. Given that part of the two signals are similar but they are not the ...
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1answer
73 views

Electret microphone into iMac 3.5mm TRRS headphone jack amplification

I have this electret microphone: http://www.farnell.com/datasheets/1505849.pdf And I've put it onto a 3.5mm TRRS (4 pole) jack to go into the iMac headphone jack. For the iMac to recognise/accept the ...
0
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1answer
58 views

Microwave amplifier characteristics - don't undertand [closed]

Please, look at http://www.rfcomp.com/hd24223.aspx (the spec file is downloadable in this page). This is a microwave amplifier, and I have several questions. 1) What is "noise figure" ? 2) What ...
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1answer
119 views

Can I connect multiple speaker boxes to a single amplifier output? [closed]

I've seen arrays of passive speaker boxes (high output passive professional PA speakers) that were connected to each other and only the last (or first) one was connected to the power amplifier (a very ...
1
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1answer
68 views

Can I run my audio mixer off the battery powering my amplifier?

Background info: I have a small battery powered 25W amplifier/speaker combo. KustomSound CB25X, with two 6V 4.5Ah SLA batteries wired in series for 12V. Fully charged, the voltage seems to be close ...
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1answer
40 views

2x50w stereo vs 100w mono amplifier efficiency

Which is better for efficiency. mono 100w amplifier or stereo 2x50w It is important because I'am building a portable speaker and it is really important for me to use little power. Also which ...
0
votes
2answers
35 views

Picking battery for power amplifier

I have bunch of TDA2003 (class AB) amp ICs and I would like to make some amplifiers with them. One would be stationary bridged 20w version and one portable version. However I'am a beginner and I never ...
0
votes
1answer
57 views

Portable headphone amplifier - max output and power supply [closed]

According to the specs listed on this page, that portable headphone amp can produce different maximum voltage, depending on the impedance of headphones: Max Output @ 600Ω 4.146 VRMS Max ...
0
votes
1answer
47 views

Power Amplifier Bypass Switch Convention?

I have an RF power amplifier (PA) for a transceiver module I'm designing. My transceiver is capable of outputting +14 dBm at the 915 MHz ISM band and the RF PA will be used to further amplify the ...
0
votes
2answers
50 views

Tube amp low voltage [duplicate]

I am building a 18W tube amplifier based on this layout. I found a schematic for a similar amp. my problem is that there is low plate voltage on all of the tubes (by plate I mean pin 3): when I ...
0
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1answer
56 views

tube amp power transformer

I am trying to build a 18w amplifier based on this schematic however my power transformer doesn't have a center tap on the secondary winding Is it possible to use this power transformer for this ...
2
votes
2answers
269 views

Is there an audio amplifier chip or circuit that amplifies certain amplitudes in a signal less or more than other amplitudes?

Like for instance, that would amplify on an exponential curve where the lower amplitudes get the maximum amplification and the highest amplitudes would get no amplification? Is there an analog chip ...
3
votes
1answer
85 views

Problem with a class AB amp

I have a simple preamp circuit coupled with a class AB power amp. The design is quite simple and I am pretty sure I already made it work a couple of years ago. simulate this circuit – ...
0
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3answers
74 views

Single MOSFET Amplifiers

Why is it that when I see single MOSFET amplifiers or even complementary ones (one NMOS and PMOS), they would use what in single BJT amplifiers would be called "Common Emitter Amplifier". The output ...