Download Triangular Wave Generator

Adana Science and Technology University
Department of Electrical and Electronics Engineering
Electrical Circuit Lab Term Project
Triangular Wave Generator
1. INTRODUCTION
In this project, you are going to design a triangular wave generator circuitry. Triangular wave is a periodic,
non-sinusoidal waveform with a triangular shape. It can be confused between triangle and sawtooth waves.
The most important feature of a triangular wave is that it has equal rise and fall times while a sawtooth
wave has un-equal rise and fall times. The applications of triangular wave include sampling circuits,
thyristor firing circuits, frequency generator circuits, tone generator circuits etc. There are many methods
for generating triangular waves but here we focus on method using opamps. This circuit is based on the fact
that a square wave on integration gives a triangular wave [1-3].
Operational amplifier based triangular wave form generator is simple circuit that is widely used in function
generators.
It is known that the integrator output waveform will be triangular if the input to it is a square wave. It means
that a triangular wave generator can be formed by simply cascading an integrator and a square wave
generator.
This circuit uses two operational amplifiers. First op amp functions as a comparator and next op amp as an
integrator. Sawtooth waveform can be easily generated by doing little modifications in the triangular wave
generator circuit. In this circuit the ‘non inverting’ terminal of second op amp is grounded, to get sawtooth
generator we just need to add a potentiometer arrangement.
1.1 Design Criteria’s
The frequency of triangular waveform can be chosen arbitrarily but mathematical expressions of frequency
equations should be presented.
Peak to peak amplitude of ramp voltage can be chosen arbitrarily but it should be suitable with your design
specifications.
2. Rules and Regulations
During the project, you may use any types of resistors, capacitors, inductors, diodes, LEDs and op-amps.
Other circuit components and integrated circuits are not allowed to use during the implementation phase.
The project will be carried out in groups of two students.
2.1. Preparation
In the preparation part, each group is required to present a proposed design solution for the project in a
report (pre-report). The report should also include simulation results illustrating the operation
of the circuit used in the design. The necessary calculations for each step (for example, resistor and capacitor
values) should be described in the report clearly.
The deadline for submitting the pre-report will be announced. Please ask the laboratory assistant about the
date. Late submissions will be penalized.
2. 2. Implementation and Demonstration
In the implementation part, you will physically construct your circuit. All team members must attend the
construction together.
You must provide your
pots, etc.) and bread-board.
own
circuit
components
(op-amps,
resistors,
capacitors,
NOTE: During the project you are going to submit two reports. In the pre-report you are required to give
the main blocks of your design with their schematics and simulation results. The second one is the final
report which contains information below.
3. Final Report
The
final
report
should
include
of the experiences gained during the project.
the
final
design,
results,
and
a
summary
NOTE: The objectives, results and the experiences should be presented clearly. This does not
mean a long report, but definitely a well-organized one. The final report should contain the
following sections:
1. Abstract and Introduction
2. Theory
2.1. Selection of equipment such as resistors, capacitors, inductors, op-amps etc.
2.2. Working principle of the project
3. Schematic diagram of the circuit
4. Simulation results
5. Description of circuit operation: Both theoretically and experimentally
6. Comments and conclusions
ATTENTION
Cheating is strongly forbidden and will be severely punished. Each project can be implemented
in many different ways. Hence, it will be easy to detect similarities. This does not mean that you
cannot collaborate with your friends. However, the allowed form of collaboration is exchanging
the ideas, not duplicating the design details.
NOTE: Some simple triangular design examples can be found in the references.
References
[1] http://pcbheaven.com/circuitpages/Triangle_Wave_Generator/
[2] http://www.ecircuitcenter.com/Circuits/op_tri_gen/op_tri_gen.htm
[3] http://www.falstad.com/circuit/e-triangle.html
[4]http://electronics.stackexchange.com/questions/115516/how-does-this-circuit-produce-a-triangularwave-output
[5]http://staff.utar.edu.my/limsk/Analog%20Electronics/Chapter%2016%20Oscillator%20Circuits%20and
%20Applications.pdf
[6]http://eee.guc.edu.eg/Courses/Electronics/ELCT703%20Microelectronics/lectures_pdf/ch04wavefunction_generators.pdf