Wireless Controlled Door-Bell

Abstract

Now-a- day\u27s wireless control of appliance is in practice, because of its advantage like no wire is needed, multiple controlling is less complicated. The controlling range of wireless doorbell is 100M. As the wireless doorbell is wireless based project, it is divided into two major section i.e. transmitter and receiver. Transmitter: This transmitter section is designed around oscillator transistor (BF194B) T2 followed by two transistor (BC148) T1 and T3. Transistor T2 generate special radio frequency determined by trimmer (variable capacitor) and coil. Transistor T1 is used as pulse generator. The output from transistor T3 is given to emitter of transistor T2 in order to get radio frequency from its collector. Trimmer VC1 is used to adjust the transmitter frequency. Receiver: The receiver section is further divided into two main sections i.e. RF amplifier section and bell trigger section. An aerial is used to receive the transmitted frequency from remote which is further amplified by amplifier and trigger circuit. The whole receiver circuit utilizes seven transistors