2B-CORD LESS REMOTE BELL
The special feature of this project is that it is controlled by remote with-out any wiring or medium. You can operate this type of hand unit transmitted by a remote with in distance of 100 meters. This project is controlled by a remote as a remote control controls TV receiver.
TECHNICAL DESCRIPTION AND WORKING
This project has been developed and successfully tested OK at TV Engineer’s Technical Lab. The project has two units for this cordless
1.Hand-unit remote [Transmitter]
2.Receiver circuit and Musical bell circuit
The technical description of these two units are as given below:-
1.Hand Unit & Remote [Transmitter]
An oscillator transistor BF 494 has been employed in this unit. The transistor produces a frequency of the value similarly equal to the frequency the receiver is capable to receive so that the raise frequency from other source does not interfare. The hand unit works on a VDC and the entire circuit is bases on three transistors. When the switch is pressed,the LED slows and indicates that the hand unit is working.
2.Receiver and Musical bell circuit
This section comprises of two stages. One stage receives the frequency generated by the transistor and feed the other stage i.e. musical bell circuit through the transistor Q3 (BC 148) after proper amplification. The transistor Q3 converts the signal received by the receiver into sound signal. Finally the audio signal is converts into musical tone by the circuit comprising of transistors Q4,Q5,Q6,and Q7.
The transistor Q4 is triggered by the transistor Q3 and speaker produces pleasant sound.
PRECAUTIONS WHILE ASSEMBLING
1.Check all the components as per the circuit.
2.Avoid short circuit while soldering
LIST OF COMPONENTS
Type from T OUED Vol II page 25 l 26