21-02-2009, 11:14 PM
Crystal Radio This a very simple radio.Only five parts are here for the radio.
Lazer Power Supply
Lazer works in high voltage supply.How can we make high voltage out of 220/110 V AC.Here gives the circuit.You can use this to make high voltage supply.But prevention should be taken to avoid shoking hazards.
The circuit takes 115 V supply and gives to step up transformer. Three diodes and three capacitors are used to eliminate the ripples of AC.
FM Transmitter
The main components are microphone, antenna, 2N2222A NPN Transistor. The range of the transmitter when running at 9V is about 300 feet. Running it from 12V increases the range to about 400 feet. This transmitter should not be used as a room or telephone bug.
Parrel Port Interface
The main components are 74LS367 Buffer IC and Case, Wire, Sockests, 18 Pin Socket (For Output), 25 Pin Connector (For Parallel Port), Ribben Cable
Phone Busy Indicator
Have you ever been using the modem or fax and someone else picks up the phone, breaking the connection? Well, this simple circuit should put an end to that. It signals that the phone is in use by lighting a red LED. When the phone is not in use, a green LED is lit. It needs no external power and can be connected anywhere on the phone line, even mounted inside the phone .
Infrared Remote Control
The transmitter circuit includes IR LED, 2N2222 NPN Silicon Transistor , 2N2907 PNP Silicon Transistor.When the switch S1 presses LED emits IR light. The receiver part mainly consists of LM308 Op Amp IC , LM567 Tone Decoder, and NPN Phototransistor and a relay.
Laser Transmitter Plus Receiver
Transmitter is a laser tube connected to high voltage supply.The message to be transmitted is supplied to Audio in side with resistance of the coil 8ohm.The other side coil has resistance 2000ohm. When audio signal is given to the coil it modulates the high voltage supply and lazer tube will emit laser light in proportional to the sound signal .
Wireless Tachometer
Tachometer is used to find out the rpm of the motors. You can make your own tachometer here
Development of a Web Based Mail Client
This project is about developing a web based mail client connecting to a Linux Server running a Mail Server and with Tomcat as the Web Server.
The Project has the following main functionality
Receiving/Sending/organizing mails using POP3
Sending mail using send mail
Performing Admin functions like managing new user, resetting passwords etc