Radio
Mobile Phone Battery Charger
Mobile phone chargers available in the market are quite expensive. The circuit presented here comes as a low-cost alternative to charge mobile telephones/battery packs with a rating of 7.2 volts, More >
High Power FM Wireless Microphone
This FM Wireless Microphone has been a very popular project with beginners and experienced constructors alike. It has been used inside guitars and as the basis of a remote control system. I do however, receive many requests for a higher powered circuit and better microphone sensitivity. More >
Mobile Car Stereo Player
Using a mobile phone while driving is dangerous. It is also against the law. However, you can use your mobile phone as a powerful music player with the help of a stereo power amplifier. This does away with the need of a sophisticated in-dash car music system. More >
Long range FM transmitter
This is very stable, harmonic free, long range fm transmitter circuit which can be used for fm frequencies between 88 and 108 MHz. This can cover 5km range (long distance). It has a very stable oscillator because you use LM7809 stabilizer which is a 9V stabilized power supply for T1 transistor and for frequency adjustment that can be achieved by using the 10K linear potentiometer. More >
Single Chip FM Transmitter
A simple FM transmitter links your home-entertainment system to a portable radio that can be carried around the house and into the back yard. For example, you can play music on the CD changer in your living room, and listen to it on a portable radio by the back-yard barbeque. More >
Mobile bug
This handy, pocket-size mobile transmission detector can sense the presence of an activated mobile phone from a distance of oneand- a-half metres. So it can be used to prevent use of mobile phones in examination halls, confidential rooms, etc. It is also useful for detecting the use of mobile phone for spying and unauthorised video transmission. More >
FM Telephone Bug
Here is a simple transmitter that when connected to a phone line, will transmit anything on that line (execpt the dial tone) to any FM radio. The frequency can be tuned from 88 to about 94Mhz and the range is about 200 feet. It is extremely easy to build and is therefore a good, useful beginner project. More >
4 Watt FM Transmitter
This is a small but quite powerful FM transmitter having three RF stages incorporating an audio preamplifier for better modulation. t has an output power of 4 Watts and works off 12-18 VDC which makes it easily portable. It is the ideal project for the beginner who wishes to get started in the fascinating world of FM broadcasting and wants a good basic circuit to experiment with. More >
Intercom circuit wireless
If you compare this intercom circuit to modern FM and wireless designs, you will certainly sau it outoded. The intercom schematic fulfills its tasks – to provide a reliable communication line and is very simple to construct. The circuit is made up of an amplifier, two switches and two loudspeakers. More >
Mobile Phone Travel Charger
Here is an ideal Mobile charger using 1.5 volt pen cells to charge mobile phone while traveling. It can replenish cell phone battery three or four times in places where AC power is not available. More >