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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44 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
37 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 ...
6
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2answers
239 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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0answers
18 views

How do I maximise the battery life of a headphone amplifier? [on hold]

I have a pair of Sennheiser PXC 450 headphones with a battery to do the noise cancellation and amplify the audio input. There are buttons on the side of the headphones for volume up/down. In order ...
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3answers
55 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
111 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
78 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
29 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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0answers
29 views

Polyphonic Speaker, Codec and Amplifier selection [on hold]

I am working on an i.MX6 based processor board in which I want to drive a speaker that helps with voice based alerts and event-status to the end user. Please help me to select the appropriate speaker ...
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1answer
38 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
49 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
63 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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38 views

Voltages and Current, which is important [duplicate]

I got my laptop adapter busted, it outputs 19V 3.42A, and I am not sure the reason why. My laptop takes in 19V but at 2A. Maybe the adapter was not the right fit. So I was thinking to build my own. ...
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1answer
45 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
97 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
votes
1answer
157 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 ...
0
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1answer
35 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 ...
3
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1answer
60 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
52 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 ...
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2answers
52 views

Output resistance of a multistage BJT amplifier

In the amplifier shown: To calculate the output resistance, this equation is used: I understand that the R5/(B+1) comes from resistance reflection, but why do they not take the resistance in the ...
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1answer
51 views

Heating coil over-drawing current

I am currently designing a circuit that includes a nichrome coil used as a heating element. The wall adapter is 25V 5A DC, which leads to different buck converters that takes it down to the ...
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2answers
62 views

Problems without ground, Amplifier & Exploding surge protector?

Not sure if this is a common issue, or how to formulate a single question, so please feel free to edit. I'm just trying to understand the situation and don't know where else to turn. I have an ...
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3answers
48 views

Difference effect filter in before and after amplifier

Is there any difference between low pass filter that put before amplifier and after amplifier? Which one is good for PC audio amplifier?
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32 views

Bypass switch for amp

I've just successfully completed a CMOY amp and I'm pleased with the result. However, I want to be able to hear the difference between the original signal and the amplified signal, so I put a switch ...
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0answers
44 views

RGB LED Strips with Arduino [migrated]

I am trying to control an RGB LED strip with an Arduino. I have followed the tutorials in both of these websites: Using MOSFETs: https://learn.adafruit.com/rgb-led-strips?view=all Using LED ...
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0answers
63 views

Identify RF amplifier IC

I am trying to repair a broken RF amplifier by replacing an IC. From reverse engineering, I know that this is a ~2 GHz, ~25 dB gain amplifier and that it is internally 50 ohm terminated. Some of the ...
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1answer
43 views

Two amplifiers in single speaker with different frequency power

I have two amplifiers using LM386. One of them I plan to use for normal amplifier and the second one I want it to be a low pass amplifier/bass amplifier and both of them will be connected to same ...
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1answer
112 views

MOSFET Amplifier?

I'm trying to create an amplifier circuit using a n channel MOSFET and I can't seem to get the results I'm looking for. I'm trying to amplify an AC signal up to the +/- Vcc but I keep getting strange ...
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2answers
45 views

Amplifier damage caused by failed power supply capacitors [closed]

MY QUESTION IS THIS: Would failed power supply caps cause peripheral damage to the amp, preamp or control circuits ? Supposedly there is "protection" for "DC offset, over current and over heat" I ...
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2answers
106 views

Amplify DC Voltage to be used like supply to 2Km

Is there something to help me to reach this goal? I want to turn on a device away from the voltage source to 2 Kilometers, my device operates at 24VDC or 48VDC / 35W. I need to know how is possible ...
2
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3answers
182 views

Turn TTL output of logic IC into output capable of driving 50 ohm devices

I want to provide front-panel trigger signals with the microcontroller inside my device. The trigger signal will be fed via a 50 ohm coax cable to another device with a 50 ohm input. A direct ...
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2answers
100 views

Help to design an amplifier

I need help designing an amplifier that is capable of providing 1 W to an 8 Ohm speaker. I have 3.3 V, 5 V or 18 V supply available to power it. I also have only one power supply available that has ...
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3answers
62 views

How to measure the resistance of digital potentiometer AD5241 in circuit when power on

I have designed a transimpedance amplifier including a digital potentiometer AD5241. The circuit is showed below. I want to test the AD5241 to make sure it works as designed. simulate this ...
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2answers
130 views

Extremely low output from amplifier

I am unsure what is wrong with my amplifier / microphone coupling. I have read many of the posts on stackexchange including the following: ...
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2answers
111 views

How to calculate battery life with a given load?

I am not very good at electricity things so any help anyone could give me would be fantastic. Here goes: I have a battery (for power tools); it is 18v and 1500 mAh (imagine DC). I'm trying to get it ...
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2answers
64 views

Amplifier design

I am having trouble calculating values for this audio amplifier. Input comes from AVR PWM operating at 44.1 kHz with high being at 3.3V. The speaker is 8 Ohm and speced for 1 Watt. First two ...
0
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1answer
47 views

Can an amplifier deliver a higher power for a short burst as opposed to continuously using the same circuit

I am struggling to understand the fundamental power requirements for an amplifier. If I want to deliver 56 V rms to a 7.5 Ohm load I can use P = V^2/R and find that I need 418 W rms. Requiring a ...
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2answers
168 views

How to characterize SNR for an amplifier with extreme low input signal?

Often that the OPAMP has an internal noise of 1uV. If I have an extreme high gain of 10000, the noise will be amplified up to 0.01V. Then, when I input a very low input signal of 10uV, after amplify ...
0
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1answer
61 views

Modeling diode connected transistor in differential amplifier

I have question about the analysis of common-mode gain of BTJ differential amplifier with active load on the Sedra Smith book. In this book, the differential-mode gain \$Ad\$ is derived based on the ...
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2answers
51 views

Biopotential measurement circuit

I have read the following paper (the link at the end), and I have not understand the schematic, which is included in the picture below. To be more specific, there is a feedback integrator, denoted by ...
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2answers
83 views

Why can't I swap a TL071 with a 741?

I constructed this circuit as shown for use as a simple headphone amplifier. I was so happy with myself that I made a second one for stereo, as well as using a 3915 to make a very simple volume ...
2
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1answer
40 views

Differential amplifier with active load Sedra Smith

I'm studing differential amplifiers on Sedra Smith book, and I have come across the following circuit. My question is: how can NMOS transistor \$Q_2\$ have a current \$g_{m2}\cdot v_{id}/2\$ if the ...
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2answers
59 views

Looking for OP-Amp with good rail to rail performance, 5V to 0V [closed]

There are thousands of OP-Amps on Farnell's website, so I thought asking the stack-exchange community might be a good idea. I am looking for an OP-Amp for use in my project. I currently have an ...
2
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2answers
123 views

Help understanding PIR amplifier analog circuit

I found a PIR amplifier circuit and would like to understand better how/why it works. The purpose is mostly to learn more about analog electronics. I found the following circuit here: PIR motion ...
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1answer
59 views

amplifier PAM8403 separated ground on the output..?

Ok, this thing PAM 8403 has separated gnd. out...for left and right.so how do I connect my headphones which have 1 ground for booth channels...? I haven,t tried it yet but I don,t know if it will ...
4
votes
3answers
216 views

How to set up an experiement to measure SNR for an EEG amplifier?

I have built an EEG amplifier with gain of 2000 and bandwith at 1~40Hz. I use an Instrument Amplifier for pre-Amp and a non-inverting opamp as post-amp and finally bandlimit at 40Hz using a 4th-order ...
2
votes
3answers
93 views

Why does my output stage rectify when I use a preceding stage?

I've been working my darnedest over the past few weeks learning more and more about amplifiers, BJTs and various topologies. As I go through Art of Electronics, I try out everything mentioned in at ...
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votes
1answer
46 views

How boost a DVB-C signal [closed]

I receive a DVB-C signal from my broadcast TV provider, and I use coaxial cables and some splitters to connect my three televisions to the coaxial wall-socket. Unfortunately I have problems to ...
0
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2answers
90 views

AC amplifier with fixed output range?

Lets say I have a sine frequency sweeping circuit (1kHz-10MHz) that goes down in magnitude, from say 3V to ...
0
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0answers
44 views

Crystal Oscillator Output Amplification

I have a HCMOS Crystal Oscillator at 50 Mhz (DataSheet). With an ac coupling and pi network I generate a sine wave with 50 ohm output impedance. In standart bjt oscillator circuits, one need to make ...