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Showing posts from April, 2017

#How to make wireless spy earpiece for your exams

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In this note we will learn about how to make your own wireless earpiece at home easily.  But firstly we should learn how speaker works. You can see the gif (animation) showing how speaker works. As we know that when we apply voltage in the inductor, the inductor acts like a magnet this effect is known as electromagnet and we all know that in every magnet there are two poles(the south and north pole). Continues changing of poles in the speaker produces sound because like poles repel and unlike poles attract. You can see in the picture down below: Because of this effect our speaker produces sound. OK, I hope you have got internal working information of speaker. But till now you only learned about speaker I will tell you more than this. I will tell you one great fact i.e. as you can see the working picture of speaker you might have notice that why the inductor only moving up and down, why not the permanent magnet ? This is because the permanent magnet is fixed in one

How to make USB Speaker for PC

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Hi, friends welcome to my blog. This is my 5th text in the blog. OK in this tutorial we will learn how to make USB Speaker for your PC. OK, Lets start, To make this we need an Operational Amplifier or simply called op-amp. In this project we are using LM386 low power audio amplifier which is suitable for any PC. OK, take a look of the circuit Circuit is so simple to understand: Pin 1 and 8 is the gain pin. Gain starts from 20-200 which means 20 is small sound peak but 200 means highest sound peak if we don't use capacitor between pin 1 and 8 then output of sound will be low but if we want to increase sound volume then we have to connect 10uf capacitor with 50v to achieve gain of 200. We are using C1 which is 100uf 50v. We are using this capacitor to block DC source from the output because DC is not suitable for good sound. And finally we are using potentiometer to control the volume. For video click the following link:- https://www.youtube.com/watch?v=d-RzdJQKp