Questions tagged [amplifier]
An amplifier can be used to adapt the range of a signal to a requirement, to make it more robust for transmission, or to satisfy interface requirements (like input/output impedance).
5,186 questions
-1 votes
0 answers
34 views
AV receiver does not output Bass frequencies - how do I fix this [closed]
I have a Pioneer AV receiver which recently went bad. I can hear only the high frequencies from the speakers. It does not matter which input source I select (tuner, dvd, cd etc.) and it happens on all ...
- 107
0 votes
1 answer
95 views
Input Noise Of An Op-amp
I want to detect a 200 nVrms signal at 30 kHz. For this purpose, I will build a circuit whose block diagram is shown below. First, I will take this signal and amplify it by 40 dB using a preamplifier (...
- 135
0 votes
2 answers
107 views
Review my 5-37Hz filter and amplifer. Will it work? Am I missing any other simulation. (Made in LTspice)
Context. I am using this filter and amplifier to detect Schumann resonances. These are EM modes of very low frequency (7,14,20,28,33) of pT range. My goal is to use a copper coil sensor. These are AC ...
- 49
0 votes
1 answer
79 views
Purpose and selection of inductor for RF power amplifier that has a VCC pin (MAX2616)
I am currently building an RF amplifier PCB for around ~2.4 GHz using the MAX2616, which is a broadband RF amplifier for 40 MHz to 4000 MHz. Looking at the datasheet, I am confused about the purpose ...
- 11
0 votes
5 answers
149 views
Can I use OPA2227 to Make Low Pass Filter and Amplifier with Gain of 50~100
I am looking for low noise opamps and the one that caught my eye was OPA2227 and is available locally. Its a dual opamp and was wondering to use it for the as low pass filter with cutoff of 38 Hz and ...
- 49
1 vote
1 answer
92 views
Trying to limit the current going through a transformer coupled to a Piezo Speaker. Why is the speaker louder using an Saturated NPN transistor?
I'm working on a project where I need to update an existing design to resolve an issue with the audio amplifier circuit overheating when the volume is set to HIGH. My approach was to replace the NPN ...
- 559
4 votes
4 answers
1k views
Why is amplifier bandwidth defined at −3 dB?
Why is the voltage amplification factor of an amplifier or a filter generally expressed by its gain in decibels, and why is the bandwidth of this amplifier defined at −3 dB?
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1 vote
1 answer
82 views
Simplest Way to Pre-Charge Capacitors in a High-Impedance Amplifier
My project includes a PIR sensor. The sensor should start reliably detecting motion within 8 seconds after power-up. The amplifiers in PIR circuits have high gain thus large resistors, causing a long ...
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