Design a unijunction oscillator circuit for operation at (a) 1 kHz and (b) 150 kHz.

Name: Problem 14, Chapter 14: Electronic Devices and Circuit Theory
Uploaded: 2022-02-25T06:55:33-08:00
Duration: 1 min 59 s
Channel: Kajal Gautam
Description: Design a unijunction oscillator circuit for operation at (a) 1 kHz and (b) 150 kHz.

step 1 Hello everyone, let us do the following question. We have to design a pulpit oscillator which op

Design a unijunction oscillator circuit for operation at (a)...

Key Concepts

Component Selection for Frequency Range

In designing oscillators for different frequency ranges, care must be taken in selecting component values. For lower frequencies, larger resistance or capacitance values are used to allow a slower charging cycle, while higher frequencies require smaller values to achieve faster charging and discharging cycles.

Unijunction Transistor (UJT) Oscillator

A UJT oscillator is a type of relaxation oscillator that uses a unijunction transistor to produce periodic output pulses. The UJT's characteristic of triggering once a certain voltage threshold is reached makes it ideal for generating repetitive timing and sawtooth waveforms.

RC Time Constant

The RC time constant, calculated as the product of the resistance and capacitance values in the circuit, determines how quickly the capacitor charges and discharges. This time constant is a key factor in defining the oscillation period and, therefore, the frequency of the oscillator.

Frequency Determination in Oscillators

The frequency of operation in an oscillator circuit is dictated primarily by the values of the resistor and capacitor in the timing network. By adjusting these values according to the relationship between the RC time constant and the desired frequency, the oscillator can be tailored to operate at a specific frequency.

Relaxation Oscillator Principles

A relaxation oscillator operates by cyclically charging a capacitor through a resistor and then discharging it rapidly when a threshold is reached. This cyclic behavior is fundamental to generating the regular oscillations needed for timing applications and is the core principle behind many oscillator designs, including the UJT oscillator.

Transcript

Please give Ace some feedback