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)

learn more… | top users | synonyms (2)

0
votes
1answer
26 views

Class D amplifier woofer filter designs

I am working on a 140W class D amplifier for my subwoofer. I am familiar with its topology but have few questions. The music source is a radio that ouputs 200mV peak-to-peak signal containing all ...
0
votes
0answers
13 views

Load cell Sensitivity

Is there a way that I could exactly know what is the value of the sensitivity of a load cell(mV/V)? The only characteristic I know is its full capacity which is 200kg and written on the sticker. I ...
0
votes
0answers
39 views

Driving a 60W 28Khz Ultrasonic Transducer

I am trying to find a circuit diagram to drive a 28Khz 60W ultrasonic transducer. Preferably, it would be DC run and be able to power the transducer at full power for at least 5 to 10 seconds as a ...
2
votes
2answers
114 views
+100

Analog preprocessing circuit (anti-alias/pre-amp) for driving ADC

Background Similarly to what Jeri Ellsworth did in her C64 Bass Guitar hack I am working on an audio-to-midi converter for my bass guitar. I am also planning to use piezo discs as sensors placed ...
0
votes
1answer
37 views

using AD620 with load cell

I am currently using an AD620 to amplify the signal coming from my load cell. I am supplying it with single supply of 5V and 0V. Below is my preliminary circuit. I am feeding half the supply to the ...
0
votes
0answers
38 views

Rf amplifier in AM receiver

I have an Analog electronics class project about AM receiver. In the project, it is stated that RF amplifier will be used after antenna. What kind of amplifier is this RF amplifier, voltage, current ...
0
votes
2answers
73 views

No output from Transimpedance Amplifier

I'm trying to set up a transimpedance amplifier reading the response from an avalanche photodiode (Hamamatsu S12572-100P http://www.hamamatsu.com/resources/pdf/ssd/s12572-025_etc_kapd1043e03.pdf) and ...
0
votes
1answer
33 views

Cross-over distortion thanks to short circuit protection

I am trying to build a AB Amplifier for school with some darlington transistors. Everything seemed to go fine until I added the short circuit protection. From that moment a cross-over distortion ...
1
vote
1answer
35 views

Designing and simulating a common source amplifier circuit

This is the problem: And this is my design for R1 and R2: So, using B2 Spice simulator I made this circuit according to the design: Vin_ and Vout_ are voltmeters. But the problem is that ...
1
vote
0answers
39 views

Self-oscillation in a commercial RF amplifier

I purchased several 50 ohm (in/out), 35 dB gain photomultiplier tube (PMT) amplifiers from a vendor assuming I could use them to read out the voltages on my PMTs. The amplifiers are AC coupled with a ...
-4
votes
1answer
65 views

How to wire subwoofer to 2.0 channel amplifier

How to wire the sub-woofer amp to existing 2 channel amplifier? I have dual LM386 for left and right channel and I would like to connect a sub-woofer. where should I wire the sub ? Is it in the ...
0
votes
1answer
55 views

AD620 with load cell help!

I have bought a 200kg load cell and an AD620 in-amp. I only want to use 100kg as the maximum weight capacity. I want to power the load cell and the in-amp from the 5v pin of the arduino. The seller ...
2
votes
4answers
168 views

NPN BJT base->emitter resistance is effectively zero?

I've been trying to better understand BJT transistors. In particular I've been trying to understand the inverting amplifier configuration. Wikipedia shows this schematic: Which shows an input ...
0
votes
1answer
55 views

PSPICE Simulation of Cascode Amplifier Not Working

Can anyone please tell me why I am getting the following "floating node" errors. I have fiddled around with the resistors to see if it affects anything, so these are not the actual values. I have also ...
1
vote
2answers
44 views

5-12v ~15w simple class a audio amp & build to 2.1 pc speaker

is there any IC that take 5-12v input and 15 w output class A amplifier for 2.1 ch pc speaker?(can be mono amp) because i've search google and found ic that only take more than 15v DC power supply, ...
0
votes
2answers
37 views

DC output of differential amplifier with active load

I've been looking around for some kind of explanation on how to get the output DC voltage on a single ended differential amplifier with active load like the one in the image It's just that i don't ...
0
votes
0answers
38 views

Common Drain Design Not Meeting Spec

I am trying to design a Common Drain amplifier with specifications below. I have reworked the problem over 10 times now and have not achieved anywhere near an appropriate solution. I have spelled out ...
0
votes
1answer
48 views

Bias-setting on valve amplifier with dual negative bias supplies

This is a general question, although the immediate purpose is to apply it to a Thorens AZ-25 amplifier from the 1960s. Schematic is here. Push-pull valve (tube) amplifier output stages are generally ...
0
votes
1answer
30 views

MP3 Player: Disconnect 3-watt speaker from amplifier when headphones are plugged in using MOSFETS and the isolated switch on an SMD 3.5mm stereo jack

Can I use Mosfets to disconnect a 3-Watt speaker from an amplifier circuit without any loss of sound quality? I'm using a microcontroller controlled MP3 player called a Flyron FN-M16P, which features ...
2
votes
1answer
119 views

Help understanding power amplifier circuit

Below is a single channel power amp circuit from the 1970s. I was wondering if someone could help me understand this circuit from a modular point of view (I'm getting lost with what I presume is ...
7
votes
4answers
383 views

Does an unloaded amplifier use more power at a higher volume?

Suppose we have a powerful sound amplifier, which is set at 90% of it's power, and nothing is being driven into its inputs. Is it using more power at this high volume (and producing heat, etc.)? Is ...
0
votes
1answer
79 views

PnP NpN transistor circuit, Were would the mic jack go?

I know the circuit says to put the mic jack parallel to the speaker, but im not exactly sure were to put it. Also, could I use another speaker as the mic? This is the pnp npn circuit I found on the ...
0
votes
4answers
46 views

-12v Regulator selection & conversion

I need help in selecting proper Regulator for regulator IC for exiting hall effect sensor.Sensor exitation voltgae is +12 to -12 v . Usually i use 7812 1A for exite +12v , I would like to know is ...
0
votes
0answers
71 views

Analyzing a MOSFET amplifier circuit

This is the problem: And this is my solution: I want to check if it is correct or I've done some mistakes.
0
votes
2answers
76 views
0
votes
3answers
139 views

Why Op amp amplifier's voltage difference zero ? [duplicate]

when I'm studying Op-amp amplifier , in the derivations we always take voltage difference between inverting input and non inverting input is approximately zero . But I can'f find any explanation "why" ...
3
votes
4answers
117 views

How to select gain for an amplifier before ADC?

The circuit has been simplified as shown in the picture. Signal source is connected with an analog amplifier, which amplifies the ac signal and also raise it by 1.5V to match with the range of the ...
0
votes
2answers
78 views

Transfer Function of PI Controller

Circuit below is an op-amp summer combined with PI controller. simulate this circuit – Schematic created using CircuitLab What is transfer function of this circut? How to calculate each ...
2
votes
3answers
147 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 ...
0
votes
2answers
106 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
votes
1answer
91 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 ...
0
votes
1answer
62 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 ...
2
votes
1answer
47 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 ...
1
vote
1answer
34 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 ...
0
votes
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 ...
0
votes
1answer
186 views

How to sense current with OPAMP?

I want to sense the current that battery supplies to the low current (few mA) circuit. As everyone said before, forcing discrete design does not make sense, so I decided to apply simple OPAMP & ...
1
vote
0answers
58 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 ...
1
vote
1answer
45 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
votes
1answer
106 views

Choosing N-channel MOSFET for 12V output [closed]

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
votes
1answer
117 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
votes
2answers
71 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
votes
1answer
49 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
votes
2answers
67 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
votes
1answer
57 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 ...
1
vote
1answer
45 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
votes
2answers
126 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 ...
0
votes
3answers
84 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
votes
1answer
34 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
votes
2answers
53 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 ...
1
vote
0answers
78 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 ...