1. R L AKSHAYA
II YEAR ECE – ‘B’
VELAMMAL COLLEGE OF
ENGINEERING AND
TECHNOLOGY
MADURAI
GENERATOR
2. A triangular wave generator is an electronic
circuit, which generates a triangular wave.
An operational amplifier based triangular
waveform generator is a simple circuit that is
widely used in function generators. The
circuit for Triangular wave generator is
designed using 741 op amp.
4. Square wave output are generated when the op-amp is forced
to operate in saturated region that is. The op-amp is forced to
swing between +Vsat and –Vsat there by resulting in square
wave output.
Initially capacitor is equal to zero at the instant when dc supply
voltage is +Vcc.+
This means that the voltage at the inverting terminal is zero.
Voltage V1 at the non inverting terminal is due to offset output
voltage (VOOT) and values of R1,R2 resistors.
Thus Vid = V1 (due to inverting terminal)
The output (Vo) is feedback to the circuit and will charge to the
capacitor connected at the inverting terminal as soon as V2 is
greater than V1 the output of the op-amp is switched to negative
saturation
SQUARE WAVE GENERATOR
6. Triangular wave generator can be formed by connecting an
integrator to the square wave generator.
This circuit requires dual op-amp,two capacitor and five
resistors. For fix R1,R2,C be frequency of triangular wave
depends on R.
As value of R is increase or decrease the frequency of
triangular wave is increase or decrease.
All though the amplitude of square wave form is constant
the amplitude of triangular wave will increase or decrease
with its frequency.
The output of A1 is square wave which is given as an input
to A2 as A2 act as an integrator. Its output is triangular wave
form.
TRIANGULAR WAVE GENERATOR
7. Working of the Op-Amp Based Triangular Wave Generator
Let us assume that the capacitor is discharged. This makes the inverting
input terminal at a voltage lower compared to the non-inverting input
terminal. This is half the supply voltage from the resistor divider network.
The output will go high till the capacitor voltage goes above half the
supply voltage. At this point, the voltage at the inverting input is greater than
the non-inverting input. Afterward, the output will go low and discharge the
capacitor. Simultaneously, the 10K resistor acts as hysteresis.
When the output goes low, the voltage divider has a 1K and a 10K in
parallel, which decreases the overall resistance and reduces the reference
(Vref) voltage. The values of the hysteresis resistor which is 10K and the
resistor divider network both can be changed to increase or decrease the
frequency.
Now the output of the Op-Amp is AC coupled to produce a signal that has
an equal positive and negative wave. This signal can easily be amplified.
