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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3answers
116 views

Questions on Operational Amplifiers

What I've learned so far from Navy school is that operational amplifiers are used as a substitute for transistor amplifiers and they contain three main circuits: the differential amplifier, common ...
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2answers
74 views

Amplifier design with three stages

As a project for my electronics 101 class, I've been assigned to design a three stage amplifier using bjt transistor to achieve a gain of 150 and input resistance of 100k and output resistance of 50 ...
2
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1answer
70 views

BJT differential amplifier output saturation

I'm making a long-tailed pair amplifier using a current mirror, the circuit has the following layout: I simulated it on PSpice and it worked, you can see the bias here: I tested it in the real ...
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0answers
32 views

Looking for an efficient audio amp circuit

It seems like all the circuits that I find are using outdated and inefficient technology that requires massive heat-sinks at anything beyond headphone levels. Is there any particular reason that there ...
0
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0answers
46 views

Simple output stage for a voltage output audio DAC

I am trying to design a simple output stage for a voltage-out audio DAC. The DAC has an differential output. In the following image VOUTP is the non-inverted output and VOUTN is the inverted output, ...
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1answer
34 views

Connect a vibration motor to a headphone jack

I would like to solve the following problem: I have a a variometer-device for an RC plane. Its receiver has a standard 3.5 mm headphone jack that provides a beeping sounds to my headphones. I would ...
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1answer
31 views

Is there any repeater with power amplifier?

I installed sensor module connected with controller. Those are connected with 6-wire cable, and it consists of 2-wire power(5V & GND), 4-wire signals(0~5V analog). First time, I thought distance ...
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0answers
35 views

Options for class D amp using Power over Ethernet

I'm putting together a design for a small amplifier that utilises power over Ethernet (PoE). The design specifications are: 10w to 30w (as long as >10w power isn't critical) 56v asymmetrical power ...
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0answers
130 views

How to sense current with transistor based design?

I am planning to build a differential amplifier for current sense purpose of microcontroller's ADC. Single ended CM amplifier should provide 3.3 V output to the ADC pin. 3.3 V, 5.2 V, and 3.7 V are ...
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0answers
51 views

How to calculate voltages on guitar fuzz circuit with pnp and npn transistors?

I have built this circuit on a veroboard, and it seems to me that it has been wired correctly. I do however get a very low output from the circuit, approx 1/2 to 1/3 of the input signal. I reckon that ...
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1answer
41 views

How do I wire speakers in multiple rooms to one amp? [closed]

I would be happy if anyone can help me with the following project I wish to build : I have an old amplifier 4ohm impedance with A and B zones, support for mono and stereo and playing both A and\or B. ...
0
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1answer
87 views

Choosing N-channel MOSFET for 12V output

I'm looking for an alternative to the STP16NF06L MOSFET N-Ch 60 Volt 16 Amp as Radioshack does not carry it. The MOSFET is meant to take a 5V PWM signal from the Arduino to drive a 12V LED strip. ...
3
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1answer
60 views

Help With Simulating Common Collector Amplifier In PSPICE

I have included as much information as possible, so it should just be a matter of pointing out something simple (hopefully). I am trying to model a biasing circuit for a Common Collector BJT ...
0
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2answers
59 views

Amplifier gain too HIGH?

I have this circuit : Two common base amplifiers for amplifying frequency in FM range (88 to 108 Mhz). The Problem is, as seen in the figure, I am getting an output of 1.5 V for an input of 10 uV. ...
0
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1answer
40 views

Summing amplifier - output voltage and power supply

I have to solve a problem where a summing amplifier has AC and DC as inputs. I calculated the output voltage min and max with the formula: $$ V_{output} = \frac{R_{f}}{R}(V_{1}+V_{2}) $$ So I have ...
0
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2answers
62 views

Trouble with CE BJT amplifier

I have the following circuit : It is meant to amplify signals in microvolt range and around 100 MHz. Now in the figure, the transistor is an ideal one. So it works fine and as expected. But as soon ...
0
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1answer
47 views

Arduino not driving RGB LED Strip

I'm using Arduino Uno with a 12V RGB Signal Amplifier and a 12V RGB LED strip. 12VDC is supplied to the amplifier. However the LED strips does not light up whether the PWN pins are set to either ...
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1answer
39 views

Speaker Amplifier for First Alert Keypad

I have gone back to the drawing board and rebuilt this for simplicity. The problem I have now is the if I use the Keypad Buss 12VDC power I get oscillation. It will not oscillate if I use a separate ...
4
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2answers
109 views

Driving 74HC logic with sub-nano second clock reference

My goal: I am trying to phase lock a 74HC-based digital circuit from a clock reference at 10~15MHz pulse repetition rate. The pulse width is around 400 picosecond. The peak voltage is sometimes below ...
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3answers
76 views

Antenna + LNA Design

I am trying to design and build an antenna + LNA board. Antenna: http://www.yageo.com/documents/recent/An_FR4_1690_2405_0.pdf LNA: http://www.avagotech.com/docs/AV02-1237EN The antenna is specced ...
0
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1answer
33 views

Current Regulator placement

I want to start building a tube headphone amp from the details on DIY Audio Projects (http://diyaudioprojects.com/Solid/12AU7-IRF510-LM317-Headamp/), but I'd like to understand what I'm doing there ...
0
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2answers
48 views

Microphone preamplifier

Can you explain about microphone preamplifier in the next circuit? http://circuitndiagram.blogspot.ru/2013/04/fm-transmitter.html Is this mic preamplifier of class C? If it is then how can it ...
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0answers
62 views

DC current amplification

i'm trying to design a battery charger for 5Ah li-ion battery. Due to cost management problems, i am not able to use advanced 5A charger controller ICs; instead, i am going to use a 1A controller with ...
0
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2answers
63 views

How does this AM Modulator work?

I have been given a question and tasked with identifying the various components. However, this circuit doesn't really seem to make sense to me. Error: RC RE inverted simulate this circuit ...
0
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0answers
46 views

Lock-In amplifier

I am currently performing experiments on FM Atomic Spectroscopy. The light from VSCEL is interacting with an akali vapor in a cell and the output is received at the photodetector. The output contains ...
0
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1answer
62 views

Simple 9v powered amp/preamp

I have attempted to build many amplifier circuits with little luck. The audio is either severely distorted, the gain is not high enough, or I pick up FM and AM broadcast stations. I would like to ...
0
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1answer
30 views

Output Pin of Burleigh PZ-150 Amplifier Driver Analog High-Voltage Power Supply Unit

I have found a Burleigh PZ-150F Analog Amplifier Driver. However I could not locate the manual. What connector cables are compatible with the output port of this amplifier? It seems there are two male ...
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1answer
92 views

LM386 audio amplifier circuit does not work

I am building a low voltage audio amplifier using LM386 op-amp. I got the datasheet from the manufacturer's website and looked at the pins and their functions. ​After, I designed my own simple ...
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1answer
53 views

How does an speaker amplifier have to be build for a given DAC output signal?

I am working on a project "cat projector" which shall "shout" at the cat when she jumps on the table in the living room. For the logic I use an Arduino board which plays/streams the sound at 22.1kHz ...
0
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1answer
61 views

Design of 5 - 15 MHz Voltage Preamplifier

I'm trying to design a power amplifier for the HF band to drive an inductive charger. The stage I'm working on now is a voltage preamplifier which needs to be able to amplify 1 Vpp to 10 Vpp. The ...
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0answers
42 views

Are these amplifiers LT1991 and LT1995 good for prototyping?

Do the above amplifiers fullfill these requirements? ISO 13485, EU-Directive 93/42/EEG Medical Devices, ISO 14971 Risk Management, IIEC60601-1 electrical and EMC tests I want to get the best ...
0
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1answer
33 views

Buffer amplifier

I have a buffer amplifier that is single supply 0-10v Lets say I give it an input (sine wave 0-10v Vpk-pk) and added a dc level-shifter to shift the input signal up by 0.5v (0.5v-10.5v sine wave ...
0
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2answers
51 views

DC - DC Amplifier for Piezo Buzzer

I have a Raspberry Pi outputting a 3.3v DC square wave that I'd like to be able to amplify to just under 20v, the maximum the piezo can handle. Just to clarify, the piezo does not have an internal ...
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3answers
436 views

Which Amplifier Should I Use After my DAC (what are I am doing wrong)?

I am working on a project "cat projector" which shall "shout" at the cat when she jumps on the table in the living room. For the logic I use an Arduino board which plays/streams the sound at 22.1kHz ...
2
votes
1answer
314 views

What is an antenna amplifier ? How does it add gain?

I don't know what exactly does antenna amplifier mean. Is it possible to increase the gain of a Tx antenna ? Where do I connect the antenna amplifier to it ? If, for example, the Tx has a power of 20 ...
1
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2answers
121 views

Is it possible to amplify near zero signals?

Is there an amplifier has an ability to amplify any signal down to -500 dBm? If there is not, can it be possible? If it is not possible, what is the weakest ever signal that can be amplified?
0
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1answer
82 views

Just I want to understand gain, power, link budget

I am a beginner, I am confused about calculating the nessecary gain and power and sensitvity to overcome path loss at certain distances. the first thing what does gain mean ? I am not talkink ...
0
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1answer
53 views

If I connected N numbers of amplifiers each have X gain 'dB“ and Y power ”dBm", how to calculate total gain and power?

sorry for bad description, I am a beginner. my question is just for knowledge and I did not test anything. If I connect for example 3 amplifier , each one has 60 dB gain and 15 dBm power. can we ...
0
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1answer
56 views

What frequency range is acceptable for a speaker in an audio amplifier

I am building an audio amplifier using a lm386 amplifier with a 12 volt supply driven from a headphone jack. I am looking for a speaker that will work well in this setup. Currently I am using a ...
2
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2answers
147 views

Low voltage audio amplifier clips on 8 ohm loads

Exposition time: One could call me a freshman in electronics and I just designed my first little audio amplifier for headphones. (Pocket design, I want to be able to drive 4 headphone pairs from a ...
2
votes
2answers
108 views

Designing a stiff voltage source using an emitter follower

simulate this circuit – Schematic created using CircuitLab I am new to electronics, and I am trying to do Exercise 2.2, page 67 of The Art of Electronics. Use a follower with base ...
1
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1answer
71 views

Op-amp and manipulating its linear output range

First of all let me give some background on the problem. I'm not a native English speaker and I have a basic understanding of amplifiers and op-amps. I am having trouble with one problem in English ...
0
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1answer
35 views

Impediance mismatch and amplifier question

I am converting an aviation headset to take a Bluetooth signal. The headset speakers are \$150\Omega\$, and the Bluetooth adapter I think is \$10\Omega\$. The mic will not be used. Can anybody ...
0
votes
1answer
37 views

What would be the peak voltage value of two combined signals (one noise and one sinusoidal signal)?

As I learned before, the peak voltage value of two combined sinusoidal signals is the sum of the two amplitudes, for example, \$0.6\sin(ax) + 0.8 \cos(bx)\$ can be \$+1.4\$V or \$-1.4\$V. Would it be ...
1
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2answers
271 views

How to improve lm386 amplifier circuit

I am new to the world of audio amplifiers however i am quickly trying to learn. I have built a simple circuit using a circuit based on what I read in the database. The circuit works however there is ...
1
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1answer
58 views

Why is my guitar amplifier acting like a radio when I touch the volume knob?

I just bought an acoustic/electric mandolin (Ibanez M511SE-DVS) that I decided to test out with the only guitar amp that I have (a Baja BG-10). It works fine, but I noticed that when I have my finger ...
1
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0answers
50 views

NPN Transistor Noninverting Amplifier

I know how to design an inverting amlifier with a NPN transistor. Now I need to make a electret microphone amplifier to connect with Arduino, which only reads positive voltage values. Is there a ...
3
votes
1answer
245 views

Why is my instrumentation amplifier's output voltage completely wrong?

I'm trying to amplify the voltage of my load cell (Wheatstone bridge I believe), but my calculated values are not the same as my experimental values. The load cell outputs a differential voltage of ...
1
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2answers
108 views

Mic Amp Mixer and Audio Distribution, Won't Work! Help! (Update 2) (Solved!)

I'm new to this forum and I really don't know much about Audio Amplifier Circuits. Hope you can help me. Here it goes: So basically what I'm trying to do is a circuit that mix 3 channels, ...
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2answers
102 views

I want to operate a DC 9v relay with a small power

Can a lightbulb be switched on using two mobile phones? (Make a call and the bulb switches on) I need this for a kid's school project so the questions like should the bulb keep glowing after the ...