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SEMESTER PROJECT;

TECHO METER

Group Members Name;

M. AMIR (BEE-13114)

AMIR AKRAM (BEE- 13126)

M. SANAULLAH (BEE-13130)

ZOHAIB HASSAN (BEE-13104)

Submitted To;

Engr. SOHAIB ASLAM

Project Description:

A tachometer is an instrument measuring the rotation speed of a shaft or disk, as in a motor or

other machine. Tachometers are the instrument that indicates the speed, usually in revolutions per

minute (rpm), at which an engine shaft or motor is rotating. Some tachometers, especially those

used in automobiles, are similar in construction and operation to automotive speedometers. Other

types, often connected directly to the shaft whose speed they indicate, are small electric generators

whose output voltage is proportional to the speed. This voltage is applied to a voltmeter whose

dial is calibrated in speed units. Another type, it is used only with engines having an ignition

system, operates by counting the pulsations of current or voltage in the ignition system, the number

of these being proportional to the speed of the shaft. There are two types of tachometer in the

market, which is analog, and digital tachometer. In this case, digital tachometer has been proposed.

Project objectives:

At the end of this project, the main objectives that need to be achieved include:

1. To design a low cost Digital Tachometer that can display exact speed reading based on

how fast an engine shaft is rotating.

2. To learn on how to construct the 3 Digit Digital Tachometer circuit.

3. To display the measured speed by using 7 segments Light Emitting Diode (LED) display.

Parts List:

1. Transistor NPN V733P = 3

2. Transistor PNP C1815 = 1

3. 4 Resistor = 2KΩ

4. 1 Resistor = 56KΩ

5. 3Resistor = 100K Ω

6. 1Resistor = 10KΩ

7. 1Resistor = 1KΩ

8. 1Resistor = 3KΩ

9. 1Resistor = 470Ω

10. 7Resistor = 220Ω

11. 1Resistor = 4KΩ

12. 2 Capacitor = 473µF




16. IC MC14553

17. IC CD4521BE

18. IC HCF4093BE

19. IC CD4056BE

20. Seven segment display common cathode

http://en.wikipedia.org/wiki/Axle

Circuit Diagram

Working:

The digital tachometer circuit is as shown in the figure. It is composed of the disk with the

permanent magnet, the Hall integrated sensor, the selective passing gate circuit, the time base

signal circuit, the power count circuit and the digital display circuit. The count circuit and the

digital display circuits use the 7 segment display LED, and display the numerical code. The input

shaft of the turntable is connected with the measured rotating shaft, when the measured rotating

shaft is rotating, it will drive the turntable to turn with it. When the small permanent magnet of the

turntable is getting through the Hall integrated sensor IC1, will change the magnetic signal into

the speed electric signal. This signal reverse-phase inputs to the input port of the NAND gate 3

through the NAND gate and further The MC14553B 3−digit BCD counter consists of 3 negative

edge triggered BCD counters that are cascaded synchronously.

CMOS LQUID-CRYSTAL CD4056BE

A CMOS-Liquid Crystal-Based Image Transceiver Device (ITD) is under development at the

Holon Institute of Technology. The device combines both functions of imaginary and display in a

single array structure. This unique structure allows the combination of see-through, aiming,

imaging and the displaying of a superposed image to be combined in a single, compact, head

mounted display.

Frequency Divider

This type of counter circuit used for frequency division is commonly known as an Asynchronous

3-bit Binary Counter as the output on QA to QC, which is 3 bits wide, is a binary count from 0 to

7 for each clock pulse. In an asynchronous counter, the clock is applied only to the first stage with

the output of one flip-flop stage providing the clocking signal for the next flip-flop stage and

subsequent stages derive the clock from the previous stage with the clock pulse being halved by

each stage.

IC DIP14 NAND GATE QUAD HCF4093BE

Then AND gate Schmitt trigger is constructed with MOS P−channel and N−channel enhancement

mode devices in a single monolithic structure. These devices find primary use where low power

dissipation and/or high noise immunity is desired. The MC14093B may be used in place of the

MC14011B quad 2−input NAND gate for enhanced noise immunity or to “square up” slowly

changing waveforms.

MC14553B 3-Digit BCD Counter

The MC14553B 3−digit BCD counter consists of 3 negative edge triggered BCD counters that are

cascaded synchronously. A quad latch at the output of each counter permits storage of any given

count. The information is then time division multiplexed, providing one BCD number or digit at a

time. Digit select outputs provide display control. All outputs are TTL compatible. An on−chip

oscillator provides the low−frequency scanning clock which drives the multiplexer output selector.

Seven Segment Display

A BCD to 7-segment decoder is functioned to convert the logic states at the outputs of a BCD

counter such as the 4510 into a form which will drive a 7-segment display. The decimal numbers

0-9 is shown on the display and is easily understood.

There are two important types of 7-segment LED display. In a common cathode display, the

cathodes of all the LEDs are joined together and the individual segments are illuminated by HIGH

voltages. In a common anode display, the anodes of all the LEDs are joined together and the

individual segments are illuminated by connecting to a LOW voltage. The 45 1 1 is designed to

drive a common cathode display and won't work with a common anode display.

Applications

Aero:

APU (air frame/group)

Rotor position

Engine

Space Shuttle

Industrial:

Mixers/Pumps

Conveyors

Compressors

Extruders

Paper/Pulp Mills

Centrifuge

PLC Interface

Motor Control

Assembly Systems

Flow Meters

Rail:

Traction Control

Speed Control

Data Recording Systems

Petrochemical:

Steam Turbines

Fans and Blowers

Pump Drives

Air compressors

Utilities:

Turbine Generators

Gas/Steam/ Geothermal

Hydro Power

Portable Generators

Governor Systems

Marine:

Engine Control Systems

Petrochemical/Utilities:

Steam & Gas Turbines

Hydro Power

Portable Generators

Fans and Blowers

Pump Drives

Flow

Compressors

Mixers & Agitators

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