2B-AUTOMATIC VARIABLE SPEED CHASER
This project is pioneer in the electronic world of display. Ten LEDs or realys can be utilized very nicely in this project. This project can be utilized for decoration of the house. It can also be used as a blinking light in the temple and also fitted in the shop very nicely for display purposes.
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 chaser available in the market now-a-days or made on electrical motors wound on wooden drum with the iron strips. But these chaser in modern electronic age give better control with multiple action. We are giving a Ten line chaser circuit here. In his project we have used IC 555 and IC 4017. A Triac or Relay can be used to handle more load. The IC 555 used in this project is a Timer IC. This is a very popular IC. The input and output of this IC can be used with TTL or CMOS logic circuit. This is being used as a multivibtrater in this circuit. The output pulse is available on the Pin no. 3 of this IC. This pulse goes to the Input pin no. 14 of the counter IC 4017. There are ten output of the IC 4017. The output is available on the Pin nos. 1, 2 , 3, 4, 5, 6, 7 , 9, 10 & 11. These output are given to the base of the transister BC147 through the resistance 4K7. LEDs are connected in the collector of these transistors. The transister BC147 is used as a buffer so that Load at the output is not directly connected to the IC 4017. In case one LED is connected at the output then transister BC147 is not required. The pin no. 12 of the 1st IC 4017 is connected to the pin no. 14 of the second IC 4017. The output of 2nd IC 4017 which is available on pin no. 3 to pin no. 11 have a diode and 100K preset for each pin. By adjusting the value of these presets speed of the LED can be changed for the display. The speed of the LED depend upon the resistance in the circuit of the preset. That is why the name of this project is kept as automatic Variable speed Chaser.
PRECAUTIONS WHILE ASSEMBLING THE PROJECT:-
* First of all check all components whether they are according to the circuit or not.
* Take care while soldering that there is no short on PCB.
* Use IC base.
* Use the value of the Resistance as given in the circuit.
* Check the diode for it polarity.
PCB [CODE 6TP08]=1
IC555=1, IC4017=2, BC548=10
IC Base [ 8 pin=1, 16 pin =2]
10mfd/25V=1, 1mfd/16V=1, 470mfd/25V=1