The crucial factor which differentiates amplifier and oscillator is its usage. The amplifier is used as a multiplier circuit which is used for increasing the intensity of weak signal while the oscillator is used as a source in an electronic circuit. The main use of oscillator is for waveform generation.
Another crucial term which makes the two components different is the type of feedback. The feedback used in the amplifier is negative feedback while the feedback used in the oscillator is positive feedback.
The difference between amplifier and oscillator does not end here. There exist some other crucial differences between amplifier and oscillator. We will discuss all those with the help of comparison chart. But before that let’s have a quick look at the contents of this article.
Content: Amplifier and Oscillator
Comparison Chart
| Parameters | Amplifier | Oscillator |
|---|---|---|
| Definition | An amplifier is a circuit which amplifies the weak signal and raises the amplitude of the signal. | An oscillator is a circuit which generates the AC waveforms of particular frequency for providing source to an electronic circuit. |
| Function | An amplifier is used repetitively in a circuit, because the signal loses its intensity after travelling to a long distance. | An Oscillator is used only in the initial stage when the circuit requires signal source. |
| Feedback | It uses negative feedback. | It uses positive feedback. |
| Requirement of Input | The input is required for its operation, it cannot operate without input. | It do not require any input to perform operation. |
| Type of Signal Generated | The Signal can be periodic or non-periodic. | The signal generated by it will be always periodic in nature. |
Definition
Amplifier
An amplifier is an electronic circuit which takes the input signal which has the low intensity or low amplitude and generates the output signal of high intensity. But what can be inferred from the above definition? It is completely fine that amplifier increases the intensity or amplitude of the signal. It clearly means it supplies energy so does amplifier generate the energy of its own?
The answer will be NO. An amplifier cannot generate the energy of its own but for this purpose, it utilizes DC source. The DC power source circuit generates the additional energy which appears at the output. The electronic architecture of the amplifier can be realized with the help of a transistor biased circuit.
The capacitor is used at the input to block any DC signal present in the input. And the capacitor connected at the end is used to bypass the DC component present in the signal.
The transistor is used as an amplifier. This is because it has the ability to amplify the weak signal. The signal which has low intensity is fed to it at the base-emitter terminal and the base region is extremely small thus, very low current is passed through it. The entire current will pass through the collector and high voltage drop can be generated by connecting a load resistor across it.
The amplifier can be a single stage amplifier or a multistage amplifier depending upon the condition that whether a single transistor is connected or multiple transistors are connected. If only one transistor is used then it is a single stage amplifier and if multiple transistors are used then it is a multistage amplifier.
Oscillator
An oscillator is an electronic circuit which can generate waveforms either sinusoidal or non-sinusoidal and acts as AC power source. The oscillator is available according to the need of frequency for a particular application. For example, for audio frequency application the oscillator used will be audio frequency oscillator. This is because the waveforms generated by it will consist of audio frequencies.
The working mechanism of sinusoidal and non-sinusoidal oscillators differs widely, the sinusoidal oscillator use resonance for generating sinusoidal waveform while non-sinusoidal oscillator uses switching principle for generation of the non-sinusoidal waveform. Usually, multivibrators are used for generation of the non-sinusoidal waveform.
Similar, to the amplifier, the oscillator also does not have its own energy but using energy conversion it can generate the waveforms of desired amplitude and frequency. The DC source connected to oscillator provides DC power to it; the oscillator converts this DC power into AC power and generates waveforms of definite frequency.
The condition for the oscillator to generate waveforms is fixed. To understand that, let’s consider a frequency selective network connected to the feedback path of the amplifier circuit. The oscillations will start when the phase shift across the complete loop will become zero. And the frequency at which this happens will be the oscillating frequency. Another crucial condition for generation of oscillations will be that the gain of this closed loop circuit should be greater than or equal to unity.
Key Difference Between Amplifier and Oscillator
- The factor which creates the key difference between amplifier and oscillator is that amplifier is used as a circuit to amplify the signal. Therefore, it is always used to intensify the strength of signals. And is used in the mid of the circuit while the oscillators are always used as the source of power in the circuit.
- The amplifier and oscillator are also different according to their working point of view, the amplifier amplifies the signal that is it raises the amplitude of the weak signal. While oscillator generates the AC signal of the particular frequency.
- The amplifier always requires an input source for its operation while the oscillator does not require any input for performing its task.
- The amplifier and oscillator both are the electronic circuits which uses different types of feedback. Amplifier uses negative feedback while oscillator uses positive feedback.
Conclusion
The amplifier and oscillator both are the crucial circuits which hold special significance not only in electronics circuit but also in communication circuitry. The major difference between their working mechanisms differentiates these two circuits. The amplifier is significant for increasing the intensity of the weak signal. While the oscillator is significant for providing AC signal source to an electronic circuit.
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