2B-BIRD CUM DING DONG
This project is a wounder in the world. Now- a- days in the world of electronics,this pleasent musical voice is very common.His project gives you two musical tones. Its is very easy and ecnomical project. By using this project in house as door bell and gadget for children.It can be heared the “tone” by kids and aged persons to attract their mind.
TECHNICAL DESCRIPTION AND WORKING
This project has been developed and tested O.K. in our TV Engineers Technical Lab. The components and PCB used in the projects published in our books are available for sale at resonable price.
The working of this project is very simple. The components used in this circuit are based on CMOS IC NV505. In this project we get Two type of tone. In this circuit the current counsmption is very low and due to low comsumption of the voltage in this project the use of this is very common in the gadgets. To run this project we require only 3 V or 6 V DC. Two transistor no. BEL 187 are used in this circuit which drive the speaker after geting the audio signal amplified by IC NV 505. In IC NV 505 oscillate, Tone generator, Rythem generator and pre-amplification are done . We get Two type of Tones from the pin no 4 of the IC. DPDT [Double pole double through] sliding switch plays a very important role, when the DPDT in position  it gives a parrot’s voice and  it gives DING- DONG tone
PRECAUTIONS WHILE ASSEMBLING THE PROJECT:-
- Do not apply two hot soldering iron on IC chip.
LIST OF COMPONENTS:
R1 1K 1
R2,3 270K 2
R 4,5 33K 2
DIODE D 1,2 IN4007 2
IC BASE 1
DPDT SLIDE SWITCH
C1 100 MFD/12V 1
C2,3 .1MFD 2
T 1,2 BEL187 2
IC NV505 1