2B-FND OBJECT COUNTER USING LDR
This project is multipurpose project and used in many other projects. IC 4033 has been used in this project. With the help of this project you can very easily count and see upto 99 in this FND counter. This project is a novelty in the electronic world. LDR has been used in this project. When light falls on a LDR it changes its internal resistance [More or Less] according to amount of light falling over it.
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 IC 4033 is decade counter and 7 segment Decoder. Working of this project is very simple. We get triangular pulse from pin no. 1 of IC4033, when light falls on the LDR. The pin no. 5 carries output and pin no. 15 is the reset pin. One no. is increased on output display when positive going pulse is received on pin no. 1 of IC 4033. On getting second pulse one more no. is added. When 0 to 9 cycle is completed then 1 positive going pulse is received on pin no. 5. This positive going pulse increases 1 no. on ICs Tens. Like this it goes upto the no. 99. Further increase of positive going pulse give 00 on the display. If no. of IC 4033 is made 3 in the project, then display of no. will be 999. The reset pin is not used in the circuit. To reset the circuit pin no. 15 is earthed through a 10K resistance and ON button is pressed on positive supply point. When light falls on LDR its resistance gets reduced and voltage becomes LOW on the pin no. 1. If light is interrupted for a moment on LDR, then resistance of LDR becomes high and due to this input pin no. 1 becomes HIGH. Again its becomes LOW, if light falls over the LDR. Like this 1 pulse is produced in each case and 1 no. increases on the display.
PRECAUTIONS WHILE ASSEMBLING THE PROJECT :-
- Use IC base for CMOS IC. Never solder this IC on directly on PCB.
- Anti-static charge spoils this IC. So do not touch with hands. Human body gets charged with electrical current due to anti-static charge.
- Never solder IC and FND directly on PCB. There is possibility of parts getting spoiled due to leakage current from the soldering iron.
LIST OF COMPONENT
PCB [Code 5TP08]=1
330E=14, 10K=1, 3K9=1. LDR=1
IC 4033 =2, FND [Common Cathode]=2, Push To ON Switch =1
Cabinet =1, DC Supply 9V =1