portable advertising board (1)

8/2/2019 Portable Advertising Board (1)

1/10

Syponsis of

Portable Advertising Board

March , 2012

INTRODUCTION


2/10

Portable advertising board is used for display purposes at shops, offices, malls,

theatres, railway station, airport and for advertisement of different products.

In this, CD 4017 IC is used for controlling the intensity of LEDs and IC 555 is

used as a timer.

Output is obtained through LEDs.


3/10

COMPONENTS USED

DIODE 4007

Diffused Junction. High Current Capability and Low Forward Voltage Drop. Surge Overload Rating to 30A Peak. Low Reverse Leakage Current.

DIODE 4148

Hermetically sealed leaded glass SOD27 (DO-35) package

High switching speed: max. 4 ns

General application

Continuous reverse voltage: max. 100 V

Repetitive peak reverse voltage: max. 100 V

Repetitive peak forward current: max. 450 mA.


4/10

IC 555

The 555 timer IC is an integrated circuit (chip) used in a variety of timer, pulse

generation and oscillator applications. Depending on the manufacturer, the

standard 555 package includes over 20 transistors, 2 diodes and 15 resistors on asilicon chip installed in an 8-pin mini dual-in-line package.

ZENER DIODE

A Zener diode is a special kind of diode which allows current to flow in the

forward direction same as an ideal diode, but will also permit it to flow in the

reverse direction when the voltage is above a certain value known as the

[[breakdown voltage], "Zener knee voltage" or "Zener voltage.


5/10

CD 4017

Pin

numberName Purpose

1 6 The 6th sequential output

2 2 The 2nd

sequential output

3 1 The 1st

sequential output

4 3 The 3rd

sequential output

5 7 The 7th

sequential output

6 8 The 8th

sequential output

7 4 The 4th

sequential output

80V,

VDD

The connection to the 0V rail

9 9 The 9th

sequential output

10 5 The 5th

sequential output

11 10 The 10th

sequential output

12 CO

Carry out output - outputs high on counts 0 to 4, outputs low on

counts 5 to 9 (thus a transition from low to high occurs when

counting from 9 back to 0)

13 LELatch enable - latches on the current output when high (i.e. the

chip counts when LE is low)

14 CLK Clock in

15 RSTReset - sets output 1 high and outputs 2 through 10 low, when

taken high

16+9V,

VCC

The connection to the +VCC rail (voltage between +3V and

+15V)


6/10

LED

This is a very basic 5mm LED with a red lens. It has a typical forward voltage of

2.0V and a rated forward current of 20mA.

Features:

1.8-2.2VDC forward drop Max current: 20Ma Suggested using current: 16-18m Luminous Intensity: 150-200mcd.

RESISTOR

The electrical resistance of an electrical element measures its opposition to the

passage of an electric current; the inverse quantity is electrical conductance,

measuring how easily electricity flows along a certain path.


7/10

STEP DOWN TRANSFORMER

Step down transformers are designed to reduce electrical voltage. Their primary

voltage is greater than their secondary voltage. This kind of transformer "steps

down" the voltage applied to it.


8/10

WORKING

Power supply is given to the step- down transformer. Preset is connected to timer

IC 555 which control the output pulse of IC 555 to flash LEDs for the given time.

Intensity of LEDs depend on CD 4017 IC. Diode 4148 helps to supply power to

the circuit and diode 4007 works for reversal of flashing.


9/10

CONCLUSION

Display board is ready to use. Flashing could be in any form and any sequence can

be adopted. Reversal of flashing can also be done..


10/10

REFRENCES

[1] B. G. Streetman and S. Banerjee Solid state electronics devices, 5th Edition, PHI.

[2] M. Morris Mano and M. D. Ciletti, Digital Design, 4thEdition, Pearson Education.

[3]A. S. Sedra and K. C. Smith, Microelectronic Circuits, Oxford University Press, 5thedition.

portable advertising board (1)

Documents