PROJECT

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CIRCUIT DIAGRAM

COMPONENTS

IC 555 TIMER PIEZO BUZZER SWITCH 7 SEGMENT DISPLAY RESISTANCES -330,220,10k,1mega,1kilo CAPACITOR SWITCH BATTERY – 9V LED TRANSISTOR BC 547

555 TIMER PIN DIAGRAMS

Source:http://www.electronics.dit.ie/

PIEZO BUZZERThe PS series are high-performance buzzers that employunimorph piezoelectric elements and are designed for easyincorporation into various circuits.• They feature extremely low power consumption in comparison toelectromagnetic units.• Because these buzzers are designed for external excitation, thesame part can serve as both a musical tone oscillator and abuzzer.• They can be used with automated inserters. Moisture-resistantmodels are also available.• The lead wire type(PS1550L40N) with both-sided adhesive tapeinstalled easily is prepared.

7 SEGMENT DISPLAY

A seven-segment display, or seven-segment indicator, is a form of electronic display device for displaying decimal numerals that is an alternative to the more complex dot-matrix displays. Seven-segment displays are widely used in digital clocks, electronic meters, and other electronic devices for displaying numerical information.

7 SEGMENT DISPLAY - VISUAL STRUCTURE

A seven segment display, as its name indicates, is composed of seven elements. Individually on or off, they can be combined to produce simplified representations of the alphanumeric characters.

7 SEGMENT DISPLAY - VISUAL STRUCTURE

The segments of a 7-segment display are referred to by the letters A to G, as shown to the right, where the optional DP decimal point (an "eighth segment") is used for the display of non-integer numbers.

7 SEGMENT DISPLAY - IMPLEMENTATION

Interfacing 7 segment Display using 7447 decoderThe IC7447 takes the Binary Coded Decimal (BCD) as the input and outputs the relevant 7 segment code. The 7447 converts the four input bits (BCD) to their corresponding 7-segment codes. The outputs of the 7447 are connected to the 7-segment display.

RESISTORS A resistor is a two-terminal passive electronic

component that implements electrical resistance as a circuit element. When a voltage V is applied across the terminals of a resistor, a current I will flow through the resistor in direct proportion to that voltage. This constant of proportionality is called conductance, G. The reciprocal of the conductance is known as the resistance R, since, with a given voltageV.

LED A light-emitting diode (LED) is a semiconductor light source.[1] LEDs are used as indicator lamps in many devices and are increasingly used for otherlighting. Introduced as a practical electronic component in 1962,[2] early LEDs emitted low-intensity red light, but modern versions are available across thevisible, ultraviolet and infrared wavelengths, with very high brightness.When a light-emitting diode is forward biased (switched on), electrons are able to recombine with electron holes within the device, releasing energy in the form of photons. This effect is called electroluminescence and the color of the light (corresponding to the energy of the photon) is determined by the energy gap of the semiconductor.

TRANSISTOR BC547

FEATURES· Low current (max. 100 mA)· Low voltage (max. 65 V).

APPLICATIONS· General purpose switching and amplification.

DESCRIPTIONNPN transistor in a TO-92; SOT54 plastic package.PNP complements: BC556 and BC557

WORKING The circuit is built around two555 ICs (IC1 and IC2), seven

KLA511common-anode alphanumeric displays (DIS1 through DIS2) and a few discretecomponents.

Foreasyunderstanding,tentirecircuit can be divided into two sections: controller and display. The controller section is built around IC1 and IC2, while the display sectionis built around alphanumeric

displays ( DIS1 through DIS2). As shown in the circuit, both IC1 and IC2 are wired as monostablemultivibrators having time periods of

around 5 seconds and 2 minutes, respectively. You can change the time period of IC1 by changing

thevalues of resistor R12 and capacitorC3. Similarly, the time period of IC2can be changed by changing the

valuesof resistor R2 nad capacitor C1.Alphanumeric displays DIS1 through

DIS7 are wired such that they show‘ HI’ when the output of IC2goes high.

CHITKARA UNIVERSITY PUNJAB CAMPUS

SUBMITTED BY: VISHESH VARDAAN VISHU

GOYAL SHAKTI