What is Oscillator: Definition, Classification

What is Oscillator?

Definition 1. An oscillator is essentially the signal generator that creates an un-sinusoidal or sinusoidal signal at a particular frequency. The various uses of oscillators are numerous because they are the primary part of all electronic or electrical circuits.

Definition 2. An oscillator is an electronic or mechanical device that operates by utilizing the principle of oscillation. It is a continuous oscillation between two objects dependent on the fluctuations in the energy. Computers, clocks and watches, radios, and metal detectors are just a few of the numerous devices that use oscillators.

Definition 3: oscillator can be described as an electronic device or circuit that can transform a steady-state signal into oscillating. For instance, an oscillator can change an unsteady condition DC signal to a periodic AC signal of that desired frequency.

Definition 4: The oscillator is a circuit that uses positive feedback amplifiers to create sinusoidal waveforms with a fixed frequency and amplitude. It is the primary source of power for electrical as well as electronic devices. The amplifier with positive feedback can generate the sinusoidal sound even without any input. These signals are referred to as oscillations. Hence, the device is referred to as an oscillator.

Definition 5: A circuit that produces an output signal having the same amplitude and frequency is referred to in the field of an oscillator. It’s also known as an oscillator, which includes both passive and active elements.

Definition 6: A oscillator can be described as a device that creates a continuous, repeating, and alternating waveform with no input. Oscillators convert unidirectional current flow from the DC source to an alternating waveform at the frequency desired determined by the circuit components.

Read This: What is PLC Programming

Classification Of Oscillators:

Harmonic Oscillator or Sinusoidal:

The signal produced at the oscillator’s output exhibits continuous sinusoidal variation in proportion to the time.

Non-sinusoidal Oscillator for Relaxation or Non-sin

In this scenario, the output signal from the oscillator’s output exhibits a rapid increase and decrease at various voltage levels. The result is a waveform such as a sawtooth wave, square wave, etc.

The Principle of Oscillators

The oscillator converts direct current that flows from to power supply and  into AC Current. 

The signals that are used by oscillators include a sine wave and a square wave.

A few examples are the signals broadcast by television and radio transmitters, clocks utilized in computers and video games.

How Oscillator Does It Work?

The basic principles that comprise oscillators are the same.

An oscillator can be described by a primary electrical circuit consisting of an inductor, and a capacitor joined in parallel. 

It is essential to know the basics of an Inductor and Capacitor to comprehend the circuit.

We know that capacitors store electric energy as a charge, and the inductor also keeps electrical energy as the electromagnetic magnetic field.

Assume that the capacitor has been fully recharged. Now the capacitor begins charging the inductor.

Once the capacitor is completely discharged, there will be no current flowing through the circuit.

This means that the capacitor has been completely removed and the inductor fully charged.

Inductors begin charging through the capacitor, and the capacitor starts charging the capacitor in the other direction. 

This was charging and discharging of capacitor and inductor produces the oscillating sound or repeated exchange and electric payment energy between the inductor.

The capacitor causes oscillations.

Oscillator Circuit using amplifier:

The oscillator circuit is made through an amplifier with feedback. Feedback can be either positive or regenerative.

The term “feedback” refers to a portion of the signal output from the amplifier that is returned into the amp’s input.

Suggested: 220+ Technical Seminar Topics For ECE

 The oscillator circuit that uses an amplifier will give regular frequency oscillations.

When we apply a sinusoidal signal as an input to the amplifier, that amplifier’s output would be the multiplier that the amp’s gain and an input signal. 

 It decides which portion of output signals generated by the amplifier will be fed into the amp’s input for feedback signals.

If the output signal of the circuit that is used for feedback gets added into the input signal, and simultaneously the input signal from the amplifier is eliminated, the feedback signal functions as an input to the amplifier. 

Once we have removed any input signals, we can determine the kind of oscillation(sustain or not) we wish to obtain. 

That is determined by multiplying the amp’s gain and the feedback portion that the circuit uses to feedback.

Stability of the Amplitude of Oscillators

The amplitude stability measures the extent to which an actual output’s amplitude is different from the desired output amplitude of an oscillator.

As the amplifier gain, it is evident that the magnitude of the waveform will change.

The value of the gain fluctuates due to the oscillator circuit’s components and consequently the magnitude.

To ensure that the payment remains constant different gain control methods are employed so that the stability of the amplitude is ensured.

Another reason for the variation in the amplitude is the voltage of the supply.

The magnitude of the waveform alters with the change in supply voltage. 

Types of oscillators:

  1. Positive Feedback Oscillator
  2. Negative Feedback Oscillator
  3. Sine Wave Oscillator
  4. A square wave or Rectangular wave Oscillator
  5. Sawtooth Wave oscillator
  6. LC Oscillator
  7. RC Oscillator
  8. Crystal Oscillator
  9. Low-Frequency Oscillator
  10. High-Frequency Oscillator
  11. Very High-Frequency Oscillator
  12. Ultra High-Frequency Oscillator
  13. The Barkhausen criterion of oscillations

The term Ab refers to loop return ratio or gain, The gain is an amplifier, and b is the feedback rate.

When Ab is -1, or Ab = 1, the feedback is either positive or regenerative. Therefore, Eqn. (1) changes to

The amplifier produces output voltage without the need for external signals or inputs—the amplifier functions in the role of an oscillator.

Sustained Oscillations

Sustained oscillations can be described as oscillations that oscillate at a constant frequency and amplitude. Based on the barkhausen criteria, sustained oscillations occur when the loop’s gain or modulus A b is greater than one, and the total phase shift of the loop is 0 ° or 360, ensuring positive feedback.

The Changing Type of Oscillations

If the modulus of A b or the amount of the loop’s gain is more significant than one and the overall phase shift of the loop is zero or 360 degrees, The oscillations generated from an oscillator are of a growing kind.

Application of Oscillator:

  1. The oscillator is utilized in Watches.
  2. Oscillators are utilized for radio Circuits.
  3. Oscillators are often used to control laptop computers, smartphones, and other devices.
  4. Royer Oscillators are utilized in a few DC to AC Inverter circuits.
  5. Armstrong Oscillator can be used to create very high-frequency sinusoidal signals.
  6. Pierce Oscillators are used primarily for Crystal oscillator circuits.
  7. Oscillators are employed in stun guns.
  8. Oscillators are employed in ultrasonic machines.
  9. In the metal detector, oscillators are also employed.