Introduction to Types of Oscillator Circuits

Catalog

I. General Introduction

The oscillators are electrical circuits make a respective electronic signal usually the sine wave and the square wave. It is very significant in other forms of electronic equipment such as quartz which used as a quartz oscillator. The amplitude modulation radio transmitters use the oscillation to produce the carrier waveform. The AM radio receiver uses a special oscillator it is known as a resonator to tune a station. The oscillators are found in machines, metal detectors, and even in weapons. The various forms of oscillators are explained below.

The oscillator transforms the direct current from the power supply to an alternating current and they are found in many electronic gadgets. The signals used in the oscillators are a sine wave and the square wave. The few of the examples are the signals are broadcasted by the radio and television relay, clocks which are used in the computers and in the video games.

There are two types of electronic oscillator’s they are linear and nonlinear oscillators. The linear oscillators give the sinusoidal input. The linear oscillators consist of a mass m and its force in the linear equilibrium. By adding the hook's low the spring produces the force that i9s in linear for small displacements. 

The different types of oscillators are listed below and some of them are explained:

• Armstrong Oscillator

• Crystal Oscillator

• Hartley oscillator

• RC Phase Shift Oscillator

• Colpitts Oscillators

• Cross-Coupled Oscillator

• Dynatron Oscillator

• Meissner Oscillator

• Optoelectronic Oscillator

• Phase Shift Oscillator

• Wine Bridge Oscillator

• Robinson Oscillator

• Tri-Tet Oscillator

II. Types

1. Armstrong Oscillator

The Armstrong oscillator is an LC electronic oscillator and to produce this oscillator we are using the inductor and the capacitor. In 912 the US inventor Edwin Armstrong has invented the Armstrong oscillator and it was the first oscillator circuit and also in 1913, this oscillator was used in the first vacuum tube by Alexander Meissner who was an Austrian engineer.

The Armstrong oscillator is known as the tickler oscillator because of the individual characteristics of the feedback signal that should generate the oscillations that are magnetically coupled to the tank indicator. Let us consider the coupling is weak, but the sustained oscillation is adequate. The following equation indicates the oscillation frequency f. The Armstrong oscillator is also called the Meissner oscillator or tickler oscillator.

f = 1 / 2Π√LC

To accomplish the 180-degree phase shift oscillation, the Armstrong oscillation uses the transistor, which is seen in the above figure. From the figure, we will observe that the output is from the main transformer which has a resistor and the input is taken from the secondary coil of the transformer. By seeing the polarity dots in the transformer secondary coil is reversed using the main coil. The operating frequency is achieved by the capacitor C1 and the main of the transformer.

2. Hartley Oscillator

The Hartley oscillator is an electronic oscillator. The frequency of this oscillation is determined by the tuned circuit. The tuned circuit consists of the capacitor and inductor, thus it is an LC oscillator. In 1915 by American inventor Ralph Hartley has invented this oscillator. The characteristics of the Hartley circuit are the tuned circuit consisting of a single capacitor in parallel with the two inductors which are in series. From the middle link of the two inductors for oscillation purposes, the feedback signal is taken.

The Hartley oscillator is parallel to the Colpitts aside from that it uses a pair of tapping coils as an alternative to two tapped capacitors. From the below circuit the output voltage is produced across the inductor L1 and the input voltages are across the inductor L2. The feedback network is given in the mathematical expression which is given below:

Feedback network = XL2 / XL1 = L 2 / L 1

Applications:

• This oscillation will generate a desired spectrum of frequencies 

• The Hartley oscillators are used in the radio frequency in a range of the 30Mhz 

• In a radio receiver, this oscillator is used and it has a wide range of frequencies

3. Colpitts Oscillator

The Colpitts Oscillator was by American engineering by Edwin H. Colpitts in the year 1918. This oscillator is a mix of both inductors and capacitors. The characteristics of the Colpitts Oscillator are the input for the working devices and they are taken from the voltage divider and made up of two capacitors which are in series around the inductor.

The Colpitts circuits consist of gain instruments such as the bipolar junction, field-effect capacitor, operational amplifier, and vacuum tubes. The output is attached to an input in a feedback loop it has a parallel tuned circuit and it functioned as a band-pass filter is used as a frequency of the oscillator. This oscillator is an electrically dual of the Hartley oscillator thus the input signal is taken from the inductive voltage divider it has two coils in the sequence.

The following circuit diagram illustrates the typical base Colpitts circuit. The inductor L and both the capacitors C1 & C2 are in series with the parallel resonant tank circuit and it provides the frequency of the oscillator. The voltage around the C2 terminal is applied to the base-emitter junction of the transistor to generate the feedback oscillations.

Applications:

• It is used to produce the sinusoidal output signals with a very high frequency 

• A very wide range of frequencies is involved 

• It is used in radio and telephone communications 

• For commercial purpose, multiple applications are used

4. Multi-Wave Oscillator

The multi-wave oscillator was invented by the French engineer Georges Lakhovsky in year of 1920 to 1940. He showed that the nucleus of the cell with the filaments stands, it is very close to the electronic oscillator and it has the capability of receiving & transmitting the vibratory details. The multi-wave oscillators are theoretical, testing for the historical instrument, and there is no medical argument is made. The multi-wave oscillator unit introduces the printed circuit board Golden ratio antenna.

Applications:

• The therapeutic action of this oscillation is really poor because of the holistically work 

• The healing process is performed by all areas of the body 

• The MWO is used in many countries worldwide by person 

• This oscillator is applied for the treatment of the cancer