Simple audio circuits

This article is a compilation of the simple and popular audio circuits we have published over years in CircuitsToday. This list involves a collection of simple amplifier circuits that you can try at home and some other audio related circuits with specific applications.  Image Source 1. 150 Watt amplifier circuit – This circuit is the most popular amplifier we have ever published. It has received over 700+ comments and is still counting. This amplifier has been tested by many readers of CircuitsToday and many of them got correct output. Most of the problems and troubles raised by readers while testing…

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Understanding the PN Junction

Whenever some one decides to learn electronics, the first question he asks may be – “Where shall I begin?“. I will say, one should begin at a junction the “pn junction“. We know semiconductor devices like transistors and diodes are the basic building units of any equipment that involves electronics, say tablet computers to the sophisticated MRI machines! How these basic units like transistors and diodes are formed ? or how are they made ? The answer lies in understanding “PN Junction”. A PN junction is the basic building block of many semiconductor devices like diodes and transistors. Note:- I…

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Delay using 8051 timer

Delay using 8051 timer.  The 8051 microcontroller has two independent 16 bit up counting timers named Timer 0 and Timer 1 and this article is about generating time delays using the 8051 timers. Generating delay using pure software loops have been already discussed here but such delays are poor in accuracy and cannot be used in sensitive applications. Delay using timer is the most accurate and surely the best method. A timer can be generalized as a multi-bit counter which increments/decrements itself on receiving a clock signal and produces an interrupt signal up on roll over. When the counter is…

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The Best & Free Android Applications for the Electronics & Electrical Engineers

The world around us is changing at a much faster pace than any one can anticipate. The world of “computing” has already seen great shifts from Desktops to Notebooks to Smartphones and Tablets. The coming decade will be more focused on mobile computing and cloud computing. Here in this article, I am listing some of the best and really useful applications released in Android market (aka Google Play), that comes handy for any one who is working in Electrical and Electronics industries/professions.  ElectroDroid – is the most popular and useful application in Android market for an electronics engineer. This app…

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How to debug in Keil Microvision

In this article we will take a look at Debugging feature of Keil uVision. In Previous Article we had seen how to create project, hex file and building Project. Once you build your project and if you see 0 errors and 0 warnings you are half way through your project. Now what is debugging? Debugging is to identify and fix bugs in your project e.g. logical or synchronization problems in the code, or a design error in the hardware.First go at Debug Tab on Menu bar, click on Start/Stop Debug. [You can also start debugging by clicking on “d” at file…

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What is Image Processing?An Introduction to basics

Sight/vision is one of the greatest powers of a human being. Our eyes can tell us the shape, size, color of any and everything which comes in front of it.An Image is a 2 D light intensity function f(x,y). A digital image f(x,y) is discretized both in spatial coordinates and brightness.It can be considered as a matrix whose row, column indices specify a point in the image and the element value identifies the intensity value at that points. These elements are referred to as pixels. As we have seen in the Working of Digital camera article on how digital camera works,…

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Software delay routine in 8051 microcontroller

Software delay routine in 8051 In an 8051 microcontroller, it requires 12  cycles of the processor clock for executing a single instruction cycle.  For an 8051 microcontroller clocked by a 12MHz crystal, the time taken for executing one instruction cycle is 1µS and it is according to the equation,  Time for 1 instruction cycle= 12 /12MHz = 1µS.  The shortest instructions will execute in 1µS and other instructions will take 2 or more micro seconds depending up on the size of the instruction. Thus a time delay of any magnitude can be generated by looping suitable instructions a required number…

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Raspberry Pi-Getting started with the revolutionary computer

Are you hearing the name “Raspberry Pi” for the first time? Then you must really recheck your reading habits! I must say that you are not up to date with the latest happenings around the world Well, Raspberry Pi is nothing more than a small,customizable computer. When you read “computer“, dont think that its something like an Ipad or a Samsung Galaxy Note. Raspberry Pi is an educational product designed for students/hobbyists to learn computer easily.  It is available in market for USD 25 and USD 35 and is manufactured and marketed by Raspberry Pi foundation – a non profit educational foundation…

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Getting Started with Keil uVision

An Introduction to Keil MicroVision Embedded system means some combination of computer hardware and programmable software which is specially designed for a particular task like  displaying message on LCD. If you are still wondering about an embedded system, just take a look at these circuit applications using 8051 microcontroller. You can call these applications embedded systems as it involves hardware (8051 microcontroller) and software (the code written in assembly language). 1. Voltmeter using 8051 2. Thermometer using 8051 3. Frequency counter using AVR Some real life examples of embedded systems may involve ticketing machines, vending machines, temperature controlling unit in…

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Random number generator using 8051

Random number generator using 8051. A  random number generator using 8051 that  displays a random number between 0 & 99 is shown in this article. The circuit it self is very simple and may not find any applications in serious embedded projects and this article is just an illustration. The circuit is based on AT89S51 microcontroller, two seven segment LED displays, two transistors and few passive components. Circuit diagram. The two seven segment LED displays are multiplexed together and their data lines are connected to Port0  of the microcontroller. Transistors Q1 and Q2 drives the corresponding displays D1 and D2….

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