Questions tagged [class-b-amplifier]

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What is the purpose of the diode in this complementary class B amplifier?

For this circuit, why did we use a diode between the bases of the two transistors?
• 161
121 views

Distorted output waveform when connecting push-pull amplifier to transformer

I'm trying to make a power amplifier to amplify a 200Hz to 5kHz sine wave (2Vpp) from waveform generator to ±150V. The load will not draw more than 600mA, so the amplifier would need to be around 100W....
47 views

Frequency Companding

I have a theory question. I want to know if compressing and expanding audio frequencies is possible or perhaps already accomplished. As a point of reference, audio companding is a signal processing ...
• 998
344 views

Problem with push pull output

Well, I'm working on an oscillator topology to excite a piezoelectric device that works at high voltages. For this I have a high frequency signal generation stage followed by a push pull amplifier to ...
• 41
134 views

Doubt about maximum efficiency of class B amplifier

In theory, it is widely known that the maximum efficiency of class B amplifier (consider $V_p = V_{cc}$) is: \eta_{MAX} = \frac{\frac{V_p²}{\sqrt{2}² R_L}}{2 \cdot V_p \cdot \frac{V_p}{\pi R_L}} = ...
• 333
1 vote
321 views

Single rail power to balanced

EDIT: I built up the circuit shown below. I had the power transistors lying around, as they're a type used for class B audio amps, and they're dirt cheap on the "jungle river" website--about ...
• 748
1 vote
574 views

Eliminating DC Offset in a Class B Amplifier with a Single-Ended Supply

I am wondering if there is any way for me to eliminate the DC offset present in this Class B amplifier circuit. The circuit is to be used to amplify music for a subwoofer and, as I understand it, a ...
• 35
31 views

Peak fundamental power of Class J amplifier

I just want to confirm if the peak fundamental power that can be generated using a class J amplifier is less than the class B amplifier since the peak drain/collector voltage is higher in class J ...
• 37
802 views

In class AB amplifier, we introduce two 0.7V sources to avoid cross over distortion. To do this, we use diodes, all of the circuits employing diodes look like, My question is, why aren't they like ...
107 views

Cross conduction in class-B power amplifier

can someone explain me why in this class-B power amplifier circuit, those two signal(driver?) mosfet generate a lot of cross condution ? the two mosfet i used : 2N7002 and BSS84 Thank you in ...
263 views

Can I use BTL audio amplifier IC in single-ended output configuration?

I am designing a widget that has to have a speaker output (low power, between 1W and 2W, 8 Ohms, low-quality) with the limitation that one end of the speaker must be grounded. There are lots of audio ...
• 9,066
186 views

How can I minimise the power consumption of this crossover clipping circuit?

I am trying to produce a circuit that produces crossover clipping distortion for musical purposes (to sound like a crappy old transistor radio). The problem I am running into (among a few, but to ...
• 1,866
93 views

Does this still count as a class B amplifier?

The PNP's emitter terminal is grounded instead of the collector terminal. is the formula:Pi= (Vcc)(Vout peak)/(pi*loadResistance) still applicable for this?... the out put has crossover distortion ...
• 31
1 vote
107 views

Current waveform in Class B amplifier

For a class B amplifier which has a LC filter at the output, gives Pure sinusoidal Voltage and current waveforms. But if we check back the waveform at Drain, waveform for drain current remains clipped ...
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5k views

Confusion between Class B and Class AB Amplifier

I am reading about output stages of an amplifier and classes of amplifier. The following circuit is named as "Class B" amplifier. From my understanding, the above circuit should be a class AB ...
• 446
1k views

Highly Distorted Output of Class B Power Amplifier

This is the circuit I made: simulate this circuit – Schematic created using CircuitLab This simple circuit incorporates differential stage - VA (Voltage-amplification) stage - OPS (Output ...
• 2,452
5k views

Difficulties with Class B Amplifier Biasing

Here I am referring to class B output power amplifier. This circuit should be easy to build and understand but I'm having problems with biasing since I don't really know how to bias the bases of Q1 ...
• 2,452
1 vote
2k views

Impedance of an Electret Mic

I have an electret mic for the design of an audio amplifier using input and output stages. How can I measure the impedance of that mic?
4k views

Design of a discrete BJT current buffer for low-current op amp

I built and simulated this BJT current buffer for an opamp based on examples I found in various places online: Link to simulation of above schematic It simulates fine, but I am pretty sure it will ...
• 1,037
7k views

Input coupling to Class AB amp with diode bias. One capacitor or two?

When AC coupling the input signal to a Class AB (Push-Pull / Complementary Pair) which is diode biased I see two different approaches: Signal connected between biasing diodes with single decoupling ...
• 1,037
10k views

How does this Push-Pull amplifier work?

I'm reading about op-amp circuits that use negative feedback from this article (question no.19). What confuses me is that the negative feedback for the Op-amp (which is being used to reduce ...
• 389
1 vote
2k views

FET Push-Pull Amplifier

I'm curious about JFET/MOSFET circuit B class amplifier. When BJT is used we only have those (+/-)0.7V limiting the transistors and causing crossover distortion. But with adding FETs or MOSFETs to the ...
• 2,452
3k views

Understanding harmonics of different Amplifier Circuits (A,AB,AB w/OP-Amp)

I have been test the circuits for amplifiers and got somewhat stuck in understanding the results for the FFT's harmonics. With a standard type B I was able to get this graph for the harmonics for ...
1k views

How do calculate / determine the reference voltage for the error amplifier of my analog PWM generator for a 0-100% duty cycle

For a school project I am building an analog PWM generator with 0.1 to full-scale linearity and a duty cycle 0-100%. Powersupply is 5 Volt and 100% is equal to 5V at the output. The frequency 1 Khz. ...
2k views

power for the load in push-pull amplifier

I wanted to ask: what is the power needed for the load resistor? Is there any problem? and what might be the solution for it? I really appreciate you help, thank you!
156 views

Amplifier for 100kHz magnetostrictive ultrasound emitter

I need an amplifier to drive an ultrasound emitter (inductive load, 120uH, 0.3 ohm). Single supply circuit would be preferable. Bandwidth - from 40 to 200kHz, output power 6-10W at 4 ohm load. The ...
• 615
824 views

Class B power amplifier using only Nch FETs

I'm building a combined linear regulator/electronic load. When the output is lower than the supply Q3 acts as a linear regulator and when the load tries to pump power back the other way, Q6 acts like ...
• 3,789
295 views

Calculation of Breakdown Voltage

How can we calculate the breakdown voltage of a BJT in ADS? Is it Possible or not in ADS? Problem:- I have a ADS BJT model. I am using that to generate high voltage output. For that i need to bias ...
801 views

Getting rid of electrical noise produced when one touches amplifier and amplifier's dials

I purchased a Lepai LP-2020A+, which is a pretty good little amp for the price, but I've modified it to make it much better and decided it deserved a better casing to look the part, too. So I ...
1 vote
1k 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 ...
1k views

Class AB amplifier

What role does Rv play in this AB class amplifier?
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2k views

Problem with a class AB amp

I have a simple preamp circuit coupled with a class AB power amp. The design is quite simple and I am pretty sure I already made it work a couple of years ago. simulate this circuit – Schematic ...
• 282
7k views

How to determine current limiting resistor values for push pull amplifier driven by op amp?

I'm looking to increase the output current drive of a high voltage op amp using a push pull amplifier. The OPA454 datasheet includes an application circuit to do exactly this, and includes some ...
• 7,633
190 views

Class B power amplifier

In this circuit from (Grey,Meyer Analysis and Design of Analog Integrated circuits fifth edition) It is stated that : "In the quiescent condition,$V_o = 0$ and $V_1 = 0$ ." What forces V1 and Vo ...
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