Solar Cell – Invention History & Story – From Selenium to Silicon

Invention History of Solar Cells – From Selenium to Silicon Well, the definition of a solar cell is simple. It is a device that directly converts the energy from sunlight into electrical energy. However, its horizons are really vast. The most significant fact is that the invention of this wonderful device didn’t happen overnight. Interestingly, the concept of solar technology is nearly three millenniums old. The first use of this wonderful technology dates back to 7th Century BC. First Recorded Utilization of Solar technology A magnifying glass was used to concentrate the sun’s rays to make fire. And would you…

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Vacuum Tube Invention History and Story behind Invention

The story behind the invention of vacuum tube   Anything in Science has its own history and some hidden truths behind its invention. It must be fascinatingly curious for any science savvy person to know the invention story of technical tools, and other innovations of Science. This is one such write up which will help you know about the researches and the advancements in the invention of the vacuum tubes. Vacuum tube? Vacuum tubes are sealed glass tubes made of vacuum that facilitates the passage of electric current. They are also called as electron tubes and they may be sealed…

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Integrated Circuit Invention History and Story Behind the Scenes

Invention of Integrated circuits – Behind the scene Have you ever heard the story behind  invention of  integrated circuits or what made people work on it? Well, if your answer is ‘No’, continue reading to unveil the truth. This article takes you through the path of invention and developments of integrated circuits. What are Integrated circuits? An integrated circuit is just a small chip that performs multiple functions. It clubs together functions of many electronic components like an oscillator, an amplifier, a timer, a microprocessor and many others into a single chip.It has the capacity to hold any number of…

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Introduction to MATLAB Tutorial

In this article, we are giving an introduction to MATLAB. This article is part of a tutorial series we are developing for MATLAB. We hope you to give us feedback, so that we can improve our MATLAB tutorial series. What does MATLAB stand for? MATLAB stands for MATrix LABoratory. Hence, as the name suggests, here you play around with matrices.  Using MATLAB an image (or any other data like sound, etc.) can be converted to a matrix and then various operations can be performed on it to get the desired results and values. Image processing is quite a vast field…

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Taking Down Forums in CircuitsToday

Hi Friends,  2 years before, we have launched Forums in CircuitsToday with great expectations. However due to lack of time on our side, we failed to monitor the forums properly. Above all the software we bought to power forums was too susceptible to spam activities. We had a tough time dealing with “automated spam” activities in forums. In 2 years time, the forum was dominated by spammers than real users. This was an unexpected and hard situation. Though we still have good intentions to keep the forum alive, we are forced to take it down for technical reasons and quality…

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The Story & History of Transistor Invention

Transistors and its path of invention We all know “transistor” is an integral part of any electronic circuit/device. It is very rare to see any circuits built without at least one transistor. This  semiconductor device is used either for switching purposes or for amplification purposes in electronic devices. They are either packed separately or found coupled to the integrated circuits.Transistors are of two types, PNP and NPN. Most commonly NPN transistors are used. In this article, lets go deep into the interesting history of transistor invention. We have developed this article by seeking inspiration from the good responses we have…

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Pulse Width Modulation – What is it?

The good definition of Pulse Width Modulation (PWM) is in the name itself. It means modulating/varying the width of the pulse (Not the frequency). To best understand what PWM is, let us first see some basic terminologies. Microcontrollers are intelligent digital components which live on binary signals. Best representation of a binary signal is a square wave. The following diagram explains the basic terminologies associated with a square wave signal. As the shown in the above diagram, the important thing to note in a PWM signal is that the time-period and hence the frequency is always fixed. Only the ON…

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The Story of PN Junction Diode

I am really excited by the amazing comments & responses I got for my two articles on PN Junction. If you have not read them yet, here they are – 1) Understanding the PN Juction and 2) PN Junction Diode Characteristics. In those 2 articles, I have tried to demystify PN Juction and explain it in very simple words. From those good responses, I assume my attempt has been successful to some extent. In this article, my objective is to take you through the “invention story” of PN Junction diode.  We are going to see how a pn juction diode…

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Breathalyzer circuit using 8051

Alcohol Breathalyzer circuit using 8051 microcontroller (AT89S51). This article is about a breathalyzer circuit using 8051 microcontroller which outputs the blood alcohol content (BAC) from the breath. The BAC is displayed in percentage on a 3 digit seven segment display. The microcontroller used if AT89S51 which belongs to the 8051 family and the alcohol sensor is MQ135 gas sensor from Futurelec. MQ135 gas sensor. MQ135 is a stable and sensitive gas sensor which can detect  ammonia, carbon dioxide, alcohol, smoke, nitrogen dioxide etc. The sensor consists of a tin dioxide sensitive layer inside aluminium oxide micro tubes, measuring electrode and…

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What are the Different Types of LED’s available

This article is a guide for any one who is interested in knowing about the different types of LED’s available in the market. This can be considered as a general informational guide on LED and a buying guide for hobbyists as well.  One important challenge I faced while writing this guide was to incorporate consumer LED’s and professional/hobbyist LED’s into a single article. Let your comments say if I have been successful in this attempt. Over the years semiconductor technology has advanced to bigger heights. The result is what we see around us in the form of smart gadgets. LED…

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