Under Graduate Engineering Students Core Course- electronic circuits II

1. Electronic Circuits IIElectronic Circuits IIElectronic Circuits IIElectronic Circuits II
Lecture notes
By
Dr.R.Senthilkumar,
Assistant Professor,
Department of ECE
Institute of Road and Transport Technology, Erode

2. Unit 4 Wave Shaping and Multivibrator CircuitsUnit 4 Wave Shaping and Multivibrator CircuitsUnit 4 Wave Shaping and Multivibrator CircuitsUnit 4 Wave Shaping and Multivibrator Circuits
• Pulse circuits
• Attenuators
• RC integrators
• RC differentiators
• Clippers
• Clampers
• Multivibrators
• Schmitt Trigger
• UJT Oscillator

3. • Upto monostable multivibrators, we had discussed in the regular
classes
• Remaining topics we will discuss here

15. Attenuators
• What is an attenuator circuit?
An attenuator circuit allows a known source of power to be reduced by a
predetermined factor usually expressed as decibels. A powerful advantage of an
attenuator is since it is made from non-inductive resistors, the attenuator is able
to change a source or load, which might be reactive, into one which is precisely
known and resistive. This power reduction is achieved by the attenuator without
introducing distortion.

16. Shown in figure below is the most common attenuator circuit known as the "pi
attenuator network". Included in this figure are the formulae for calculating the
required resistances R1 and R2. An attenuator may be used in either audio or
radio signal circuits.
The factor K is called the ratio of current, voltage,
or power corresponding to a given value of
attenuation "A" expressed in decibels.
"K" is the number 10 raised to the power of the value of
attenuation "A" in dB, divided by 20.
K = 10 ("A" / 20)
at 3 dB attenuation and calculate our "K" factor.
K = 10 (3 dB / 20) = 10 (0.15) = 1.4125

17. • "T" network attenuator

18. Pulse circuit- Testing Pulse input to RC circuit
Figure shows a RC High pass filter
The above equations give the expressions for
output voltage and gain Vo/Vi

19. τ = RC =Time Constant