An electronic oscillator is an electronic circuit that produces a periodic, oscillating electronic signal, often a sine wave or a square wave. Oscillators convert direct current (DC) from a power supply to an alternating current (AC) signal. They are widely used in many electronic devices. Common examples of signals generated by oscillators include signals broadcast by radio and television transmitters, clock signals that regulate computers and quartz clocks, and the sounds produced by electronic beepers and video games. Oscillators designed to produce a high-power AC output from a DC supply are usually called inverters. There are two main types of electronic oscillator: the linear or harmonic oscillator and the nonlinear or relaxation oscillator.

3. We would like to express our special thanks of gratitude to our
teacher Dr. Praveen Kant Pandey who gave us the golden
opportunity to present this wonderful presentation on the topic
(OSCILLATORS & GENERATORS), which also helped us
in doing a lot of Research and we came to know about so many
new things. We are really thankful to him.

4.  a device that incorporates active and passive circuit
elements to generate sinusoidal and other repetitive
waveforms.
 portion of output is feedback to sustain the input and
drive itself as a signal generator.
The type of the waveforms generated
depends upon the components in the circuit.

5. An Amplifier
Wave Shaping Network
Feedback path
DC power supply

6. Af = A
1 A
1. The loop gain of the circuit must be equal to (or greater
than) unity.
2. The phase shift around the circuit must be zero,i.e,that is 0
or 360.
Af = A
1-β A
𝑉𝑑

8. RC PHASE SHIFT

9.  The basic RC Oscillator which is also known as a Phase-shift
Oscillator, produces a sine wave output signal.
 The op-amp is used in the inverting mode ,therefore any
signal appear at negative terminal is shifted 180o.
 The additional phase shift required for the oscillations is
provided by the cascaded RC network,i.e ,3 RC network
correspond to 3 x 60o =180o

10.  At some specific frequency when phase shift is exactly
180 and gain is large the circuit will oscillate at that
frequency.
 Frequency for the oscillation :-
n:-no of RC stages
R:- Resistance in ohms
C:-Capacitance in farads
The gain at this frequency of the amplifier must be,
𝑅 𝐹 ≥ 29
𝑅1

11.  The tremolo effect is a cyclical amplitude (volume)
modulation of the input signal and is used in musical
instruments incorporating sound waves.
 A tremolo circuit consist of LFO(low frequency oscillator)
which is a RC phase shift oscillator
in this case.

12.  The frequency is determined by the RC network in the
circuit.
 Low frequency generator is acting as a phase splitter ,it
splits up the low band and high band signal .

13. WEIN BRIDGE

14.  based on a frequency-selective form of the Wheatstone
bridge circuit.
 The bridge has series RC network in one arm and
parallel RC network in the adjoining arm.

15. This condition occur only when bridge
is balanced that is at resonance.
And the resonant frequency is given
by:-
i.e., Xc = R

16. Zs = impedance of series combination
Zp = impedance of series combination
Zout = Zp 1
Zp + Zs 3
Gain for non-inverting amplifier
( Av ≥ 3 )

17.  To provide excitation
for AC bridges.
 To provide signals for
testing filters.

18. SQUARE WAVE GENERATOR

19.  A square wave generator generates a square
waveform when op-amp is force to operate in
saturated region.
 The operation take place is repetitively between
+𝑉𝑠𝑎𝑡 and - 𝑉𝑠𝑎𝑡.
 Hence the output is either positive or negative
depending upon differential voltage 𝑣𝑖𝑑.

20.  The equation for 𝑉𝑈𝑇 :-
𝑉𝑈𝑇= 𝑅1 (+ 𝑉𝑠𝑎𝑡)
𝑅1+ 𝑅2
 The equation for 𝑉𝐿𝑇 :-
𝑉𝐿𝑇= 𝑅1 (- 𝑉𝑠𝑎𝑡)
𝑅1+ 𝑅2
The output frequency :-
The highest frequency generated is set by the slew rate of
the op-amp.

21. TRIANGLE WAVE

22.  Triangular wave generator is simple circuit that is used
generate triangular waveform .
 The output wave form of integrator is triangular if its input
is square wave.
 Thus this generator easily be formed by connecting a
integrator to the square wave generator.
 As the R1 decreases or increases ,the frequency of
triangular wave will decrease or increase.

23.  -VRamp = - R2 (+Vsat)
R3
 +VRamp = - R2 (-Vsat)
R3
 Vo(pp) = (+VRamp) – (-VRamp)
= 2 R2 (Vsat)
R3

24.  http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/square.html
 http://www.circuitstoday.com/square-wave-generator-using-op-amp
 http://www.electronics-tutorials.ws
/oscillator/rc_oscillator.html
 http://www.learnabout-electronics.
org/Oscillators/osc31.php
 http://www.techulator.com/ resources/10114-How-
Phase-Shift- Oscillator-work.aspx