Power supply has a considerable role in electronic communications equipment. The power supply furnishes the voltage and current requirements for electronics circuit operation. Special high-voltage power supplies used in microwave systems and laser systems enable large power handling tubes and semiconductor circuits to operate. In this section, we are going to look at popular types of power supply circuits and some faults that can occur in them. In this section, we’ll also learn to troubleshoot a traveling wave tube amplifier. Improper operating of a TWT can nearly always be traced…
A single IC as illustrated in the figure, consist of almost all the active components that an AM receiver constitutes in general cases. However the resonant networks required for the circuit operation, needed to be supplied externally. RF converter, IF amplifier, detector and AGC circuit, a built-in regulator zener diode, and the audio preamplifier stage are the crucial portion of the IC. We can also see in particular AM receiver system ICs, the RF amplifier is included and the tuning meter/ pre-amplifier is omitted completely from the system. Few parameters…
Introduction of Multivibrator We have already studied the working of several sinusoidal oscillators. For certain purposes, we need non-sinusoidal generators, also called relaxation oscillators. A relaxation oscillator generates voltage or current which varies abruptly one or more times in a cycle of operation. Typical examples of non-sinusoidal generators are: multivibrator, Schmitt trigger, UJT oscillators, blocking oscillators, saw-tooth (sweep) voltage generators, saw tooth (sweep) current generators etc. Multivibrators are used for various purposes such as generation of square waveforms, frequency counting, frequency division, generation of time delays and storage of binary…
The IC described here is particularly designed for single audio channels, so as to offer Dolby B-type noise-reduction features. Along with the internal power supply regulator, the circuit of dolby noise reduction processor IC requires a series of amplifiers. In addition to this, some external RC networks are also required for the system. These networks serve a special purpose in the system. A single network comprising five capacitors and three resistors is connected to four external leads. The other network which constitutes of three resistors and three capacitors forms a…
LEDs are probably the only components to offer a wide range of applications. It can be used either to describe the working of the circuit or with LED itself, a complete circuit can be developed. The LED flasher circuit makes use of this amazing component to turn it flash on and off. The LED flasher circuit employs a voltage source, capacitor, and LED. This project requires voltage supplies varying from 1.15 volts to 6 volts typically because of which the circuit can be operated with a single battery cell making…
The circuit designed hereby constitutes of the major portion of every AM/FM receiving system. It can be used to design a complete AM/FM receiving system. Addition of components like audio power amplifier, AM converter (mixer and local oscillator, AMIE detector, FM IF and FM detector) form the internal building block of entire receiving system. However, for the receiving system to function flawlessly, external components like capacitors, coils, and resistors need to be included in the circuit which is obvious necessity. The operating characteristics such as bandwidth and gain of the…
These days, most BEP readers interested in Audio Engineering asked for a circuit that can recognize the polarity (positive and negative terminals) of the speaker. I had also experienced the problem of the polarity of speakers about a few years ago while testing one of my projects. At that time, I had used a multi-meter to test the polarity of the speaker. While testing a multi-meter you have to concentrate on the movement of the speaker cone which is a difficult job especially for a small speaker. For the large…
Bisection method is an iterative method used for the solution of non-linear equations, also known as binary chopping or half-interval method. Bisection method is based on the repeated application of the intermediate value property. It means if f(x) is continuous in the interval [a, b] and f(a) and f(b) have different sign then the equation f(x) = 0 has at least one root between x = a and x = b. This method is most reliable and simplest iterative method for solution of nonlinear equation. a < x < b…
Introduction to Best Arduino Projects They are some of the best Arduino-based projects available at bestengineeringprojects.com which have gained enough popularity within short notice of time. We have selected a few Arduino projects as the best Arduino projects which can be a milestone in the field of easy electronics. A number of people are able to transform their dream into reality using the Arduino platform. The fact that this device is a simple microcontroller-based board that performs multifunction and also has multiple features, has attracted lots of eye towards it.…
Intercoms and calling bells fit properly only in the luxurious hotels, lodges and high class buildings. In small vicinity like small hotels, offices and clinics, these are not the correct options to choose for communication between the working/assisting staffs and people. It is all because of the cost and the fact that this provision can be made for limited number of points and other alternatives are chosen over it i.e. call indication systems. In early days, such call indications systems employed multiple distinct paths/cables to connect each call point to…
