FM Tracking transmitter

jacky March 8, 2012 23 Comments
Description. The circuit presented her will transmit a audio tone in the FM  band. The circuit can be used as a tracking signal transmitter or a remote control transmitter. The circuit uses only easily available components and any one can build this. The transmitter has a range of 100m @ 9V supply, with a matching antenna. The NE555 timer (IC1) is used for producing the audio tone. The first JFET (Q1) is wired as a Hartley oscillator which is...
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Low cost fire alarm circuit.

admin January 21, 2014 91 Comments
Description. When there is a fire breakout in the room the temperature increases. This ultra compact and low cost fire alarm senses fire breakout based on this fact. Transistor BC177 (Q1) is used as the fire sensor here. When the temperature increases the leakage current of this transistor also increases. The circuit is designed so that when there is an increase in the leakage current of Q1, transistor Q2 will get biased. As a result when there is a...
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Aircraft radio circuit

admin January 24, 2012 11 Comments
Description. Here’s a low cost radio circuit that can be used to listen to the radio conversations between aircrafts. The radio circuit based on transistor 2N918 and diode 1N82 receives in the 220Mhz to 400Mhz range. Capacitor C1 and inductor L1 forms the tank circuit for tuning. Diode D1 performs the detection. Transistor T1 performs the necessary amplification. The out put audio signal is just enough to drive a small headphone. For driving speakers. Circuit diagram with Parts list. ...
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AM Transmitter circuit

admin November 27, 2018 89 Comments
Simple AM Transmitter Transmitters are devices that are capable of transmitting audio as radio waves from an audio device. There are two types of transmitters; FM & AM. We have many posts on FM transmitters, so we decided to make one on AM transmitter. AM transmitters create radio waves using Amplitude Modulation (that’s why AM). That means only the amplitude of the waves gets changed but the frequency remains the same. In this case, the frequency of career frequencies falls...
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Single chip FM transmitter circuit

admin November 27, 2018 21 Comments
Single chip FM transmitter An FM transmitter is a device that can transmit audio from an audio device as a radio signal. Doing so allows the audio to be picked up and played by an FM radio in the transmitter’s range. The FM (frequency modulation) device allows the waves to move in predefined frequencies so it can be identified by a radio tuned o this particular frequency range. FM transmitters can be made in different ways. Circuitstoday alone has...
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Single Chip FM Radio circuit

admin October 30, 2018 94 Comments
In this project, we’re building a Single Chip FM Radio. The heart of this circuit is a digital IC – TDA7000. The design involves proper use of inductors and capacitors with correct values. Since the IC is dedicated to build radio circuits, this circuit is very much reliable to an extent. Description. Here is a compact low cost FM radio circuit using IC TDA 7000. This circuit is designed as per the data sheet and the result is excellent.Ideal...
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Direct Coupled Radio

admin October 30, 2018 3 Comments
In this project circuit, we’re building a Direct Coupled Radio Circuit using an inductor and 3 transistors mainly. This is a very basic, low cost, hobby purpose circuit – just for the learning purpose of “direct coupling” method. If you’re looking for a good radio circuit, you’d be better off with our FM Radio Circuits collection. Description Here is the circuit of an excellent direct coupled radio ideal for listening to near by stations.The circuit uses Q1 as a...
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Metal detector circuit

Metal Detector Circuit

jacky July 25, 2018 44 Comments
Metal Detector Circuit I always wanted to make a metal detector seeing how cool it was in all Hollywood, Bollywood movies. One thing I realised is; things aren’t as difficult as you think it is. After all, I found that a metal detector is really simple and easy to make. So in this post, I am sharing with you “How to make a metal detector” Description This is the circuit diagram of a low cost metal detector using a...
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Radio circuit using opamp

Simple Radio Circuit using Op Amp

admin October 17, 2018 13 Comments
Simple Radio Circuit Op-amp is the short form for Operation Amplifier. It is a device used to amplify voltage, and is very popular due to its high gain amplification. It can often amplify voltage to hundred times of what is input. This project is aimed at making a simple radio circuit using an opamp. Description This is a low-cost simple radio circuit based on opamp which can be used to listen to nearby stations. A simple op-amp radio basically...
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Radio collar transmitter

Radio Collar Transmitter

admin October 17, 2018 13 Comments
Radio Collar Transmitter Radio collars or tracking collars are tracking devices used to study animal migration patterns, they are also used to keep tab of endangered species. In India, radio collars are commonly used on tigers to keep track of them. Obviously, a radio collar has a strap which is worn around the neck of the animal and a radio transmitter. Our project here is to make such a radio transmitter device which can be used for tracking. We are...
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