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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37 views

Simple lightweight high power amplifier circuit

I'm looking for a way to amplify a 12V sinusoidal signal to drive a set of transducers at ~120V with an overall power of 100W. The quality of the output signal does not have to be good, simplicity ...
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0answers
34 views

Help fixing board with burned capacitor [on hold]

I have a board from a sound bar with a burned component. I think it was a capacitor but I'm not sure the best method to verify and figure out the right part to replace it with. If it's not ...
0
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1answer
57 views

Low noise amplifier

Recently, I got a low noise amplifier (i.e., ZFL-1000LN+ from MiniCircuits, http://194.75.38.69/pdfs/ZFL-1000LN+.pdf) with two wires already soldered in the turrent terminal pins. Today I have been ...
3
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3answers
82 views

Design help! — Play a pure tone into a mic and depending on its frequency a specific LED will light up

I'm still new to electronics and am making this in order to learn more about circuit design and filters. I do not want to use microcontrollers. I want a purely analog solution. I'm trying to make a ...
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2answers
73 views

Why is the collector- emitter voltage (Vce) not getting biased?

This question is an extension for my previously asked question here: Why is the voltage across collector and emitter pushing itself to 0.7 volts? A colleague of mine suggested that I take a look at ...
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0answers
34 views

Buzz from Fender px-2200 Power Amplifier

I have a Fender PX-2200 series PA and mixing console, which I use nearly every day. It is a 600 watt output unit using 2 x 300w amps (or so I'm told) powering two separate channels. Recently, I was ...
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3answers
212 views

Can somebody please analyse this circuit

Can somebody explain to me how this circuit works? i understand that it is an audio amplifier circuit and it inverts the signal, and inverts it again, but i am not sure why this is the case. also ...
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2answers
71 views

Why do we need to rectify or amplify the current/voltage? [on hold]

I am a beginner in Electronics. What i read now a days in my text book is about diodes,transistors etc. They are used for some rectification and amplification etc ? I wonder why do we need to give ...
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1answer
65 views

Should bias voltages still be in range without driver/output transistors?

A class AB audio amplifier has both positive and negative +/-40v rails. There is a differential amplifier feeding a trans-impedance transistor. The transistor is also a current source for an ...
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2answers
58 views

Pickup Signal from a Wire - without a physical connection

I am not an RF engineer and I don't even know if what I'm asking is possible. The idea is that the system will be outputting a 12V 10KHz signal onto the wire with one end connected (Wire Under Test) ...
3
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2answers
39 views

Output power vs idle power of an audio amplifier

Let's say I have a AB class power amplifier that is able to give an average output power of 30W on a 6 ohm loudspeaker. Now in ...
1
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1answer
81 views

Why is the voltage across collector and emitter pushing itself to 0.7 volts?

I designed a single stage transistor amplifier as shown in this schematic: I constructed this on a breadboard and applied the DC bias voltage to check the biasing conditions. Prior to this, I made ...
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1answer
40 views

WWVB Antenna Reciever 1st Amplifier stage, no signal

I made a high input impedance JFET CS amp as the 1st amplifier stage for a 60kHz Loopstick Antenna. I am using an RF JFET (J211) and ceramic capacitors. The only signal I see is a 60Hz sine wave ...
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1answer
65 views

Audio op am for low noise high volume

I am trying to make a high quality circuit to take mp3 (stereo) signal and drive a 4 ohm speaker. I have been using the LM368 as in the picture below and this has ok quality when the volume is low but ...
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votes
1answer
74 views

How to design a circuit with array of amplifiers? [closed]

If I have a very tiny signal voltage and I want to amplify it 100 times higher with low noise amplifier, how should I design the circuit? I mean for example how should I know that I need capacitors ...
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2answers
49 views

Bulletproof ESD Powersupply Inputs

I have a power amp that is essentially functions like a benchtop supply, and you can connect banana plugs into it. I would like to protect it against ESD, but also protect the amplifier. People in our ...
1
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1answer
48 views

Class AB Amplifier Frequency Response

I have designed an AB Audio Amplifier, but even though the gain is acceptable, the frequency response is terrible.As seen in the schematic, there is a feedback/preamplifer stage and an output stage, I ...
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3answers
590 views

What is the purpose of the 10K resistor that is connected across the input and the supply?

I was checking out some transistor amplifier circuits online when I came across this one. Now my question is what is the use of 10 kilo-ohm resistor that is connected between the power and the input ...
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1answer
27 views

What is the significance of Input Resistance and Output Resistance in CE,CC,CB amplifiers?

Common Emitter, Common Collector and Common Base amplifiers have their specific purpose with differing voltage/current gains. For example, I know for a common collector has a voltage gain of ...
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1answer
66 views

Need to Amplify 13mv to 5volts using a LM324 op Amp

I am using a 13mv input on a LM324 op amplifier. I am trying to get a gain of about 384 to 5 volts. I am not getting any voltage on the output?? Can anyone offer any suggestions why this circuit ...
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2answers
68 views

Is it possible to make an “easy” high power amplifier? [closed]

For example, an LM317 can handle currents up to 1.5 amps, but if you add a few 2N3055 power transistors you can get pretty much unlimited power (if you have good enough cooling and components that can ...
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1answer
39 views

How can I amplify 868MHz transmission done with a wire antenna?

My garage door is sending its status to a control device we have in the house. This signal is not always received by the control unit so it wrongly shows the garage door is open when it's closed. The ...
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2answers
80 views

Does a CE amplifier draw more power when it is amplifying than it is sitting idle?

Does a CE amplifier draw more power when it is amplifying than it is sitting idle? In quiescent mode the power consumption would simply be Vcc * Icq. How about the power drawn from the DC power source ...
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1answer
40 views

what is the difference between positive and negative feedback in an opamp? which is used when? [closed]

how is it said that opamp with negative feedback operates in linear region?and positive feedback is unstable? then how do we use positive feedback in schmitt trigger?
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1answer
23 views

How to using a 3.5 mm stereo plug mic with a EM11G LM 386N-1 amplifier

I have built a simple amplifier circuit using a EM11G LM 386N-1 amplifier chip which follows the following design (cap and resister values are slightly different): I connected this mic to the ...
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3answers
71 views

How to explain the behavior of a PNP transistor as a transimpedance amplifier?

Can anyone explain how Q3 behaves? I mean in a way that: If base of Q3 goes positive ... increases.. ect and if base of Q3 goes negative ... happens and so forth and so on. in that fashion. I see ...
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4answers
73 views

Confusion with current in voltage-out amplifier

Why do we call some amplifiers this way? I mean lets say one call an amplifier as: "Current in voltage-out amplifier". I dont understand this because if current is in then inevitably voltage is also ...
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1answer
40 views

Single ended to differential amplifier workings

Hello electronics experts, I do not yet have enough reputation to post more then two images. For the images please see: http://imgur.com/a/dizis I have a single ended signal that i want to convert ...
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1answer
53 views

How to understand rail to rail input circuit?

I watched an input circuit for ground rail as follows, Why do I have to place a current source here? If I place a resistor instead, there will still be current flowing in emitter-base direction for ...
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0answers
19 views

(VCA - VGA) Design of an amplifier controlled by a ramp

I would like to design a circuit with an AOP which will have a variable gain controlled by a tension (a ramp). Could you help me and explain me the circuit please? Thank you, Farad
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5answers
314 views

What is the function of this transistor?

There is a tutorial on multi-stage amplifiers. It doesn't explain every details. The first stage is the typical amplifier with stable bias, and the last stage is the push-pull amplifier. But there is ...
0
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1answer
47 views

How to increase the output power for this audio amplifier?

I have created this simple single stage, transistor audio amplifier using voltage divider bias. For testing, the source of input signal was audio from laptop and the output was from a 4 ohm, 0.25 ...
0
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5answers
83 views

Is there a difference in the meaning of power and current amplifier terms?

I understand the difference between voltage amplifier and power or current amplifier. For example in an audio amplifier there are usually three stages: two voltage amplifiers and a power amplifier at ...
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1answer
55 views

Info About Amplifier [closed]

What will happen if we apply amplified audio to an audio amplifier? I want to increase volume of my Speakers. Is there any way to increase power of Amplifier?
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1answer
34 views

TPA6111 Stereo power amplifier to mono setup

I have a TPA6111 stereo audio power amplifier part (http://www.ti.com/lit/ds/symlink/tpa6111a2.pdf) that has this typical application (from the datasheet): My application requires a mono signal ...
0
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2answers
113 views

How are the resistor values R1 and R2 calculated for a transistor amplifier that has a voltage divider bias

Good day friends I am trying to analyse the working of transistor amplifiers with a prime goal of designing a good audio amplifier that does not produce much distortion in the output. I am ...
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1answer
43 views

Pass line level signal through electric guitar

I have an idea for a project where I want to pass a line level signal through my electric guitar. The idea is to have a 3.5mm jack input on my guitar, to which I can input a line level signal. Then ...
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0answers
37 views

Multistage CMOS amplifier design

my professor gave us a task to design a multistage amplifier using NMOS and PMOS transistors with a minimum width W=18um, 1.8v battery(multiple if needed and any sort of resistor/capacitor. The only ...
2
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1answer
97 views

Why Bandwidth Affects Response Speed

This is a follow-up question to (this question). Here is the amplifier section in question: In the answer, the author (@Brian Onn) gives the following explanation: "Slow vs. fast is not about ...
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2answers
58 views

Amplify the signal from ACS712 to adc

I am trying to amplify the signal from ACS712 to read it better. The problem is that I am using an 8-bit ADC, and what I want to take measure are things like energy-saving lights, or other things with ...
0
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2answers
44 views

How to understand dynamic range of op amp from TI's book

I am reading TI's op amps for everyone. I am very confused about its description about dynamic range as follows I have some questions about it, Since it is the maximum output voltage the op amp ...
0
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1answer
51 views

how to sync leds with the beat?

how do i make led strip flash with the beat (subwoofer) without risking burning them out and im using a car amplifier that kicks out 1250w peak for the subwoofer i tried using a multimeter i got ...
0
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3answers
47 views

BJT Forward Active

Regarding BJT, forward active mode of operation i don't seem to get something. I will use NPN type. In the forward active regime, Vbe>= 0.75 V, so electrons flow from the emitter through the base .Ok, ...
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2answers
85 views

What to do with unused chip amp channel?

I'm planning to use STA540 in a guitar combo, because it's one of a few chip amps that can give me about 15W with 12V supply and 4ohm speaker. My problem is that the chip has four amplifiers and I ...
3
votes
2answers
46 views

Micro-Voltage Reference

I need a micro-Voltage reference to calibrate my micro-Volt amplifier. The ICs only go down to 200mV, fixed. So how should I go about this? Use the lowest I could find, then use a Voltage Divider to ...
0
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2answers
77 views

Transistor Based Amplifier and DC Only Negative Feedback

My analysis of Heathkit RLC Bridge continues (previous question here). This time I've been trying to analyze the feedback amplifier section shown below and taken from the original document IB-5281 ...
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2answers
33 views

Linear operating range of an amplifier as a function of frequency

How does the linear operating range of an amplifier (the linear part of the function that describes Power Out vs. Power In), both in theory and in practice, vary with frequency? In other words, if I ...
0
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1answer
38 views

LTSpice Instrumentation amplifier simulation output

I am using an LTSpice model for an instrumentation amplifier (AD8222) to learn how to simulate things in LTSpice. My output is not what I expected. My model is based on this description: ...
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1answer
38 views

class AB amplifier input resistances

I was wondering if you could help me out, what would be the effect of changing R1 & R2. I have looked online, but mustn't be searching in the right place! My guess is that you would adjust them to ...
3
votes
3answers
441 views

What is the advantage of analog subtractor/summer?

Why we use opamps like in figure 2 instead of just add or subtract signals from each other as shown in the first figure? Is this choice differ if I apply DC signal instead of AC one? Sorry if this is ...