Rel Buzz + Motors

8/8/2019 Rel Buzz + Motors

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Interfacing withrelay , buzzer and motors.


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C ontents

Relay working , application.

Interfacing with 8051.

Programming of relay.

Programming of buzzer.

About motors.

Programming of motors.


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R elays

An Electromechanical device

Relay operates on +5vswitches to +12v or 220 v state

Wide variety applications suchas in telephone exchanges,digital computers andautomation systems


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Inside Relay


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R elay OperationWhen there is no voltage applied on coil, switch is open.When a voltage is applied on coil , magnetic field isproduced.It attracts the armature towards the 2 nd pin closing theswitch.


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R elay application

Bulb is ON , when voltage is applied on relay input(coil).

Bulb is OFF , when no voltage is applied on relayinput(coil).


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OPTO C OUPLE RS:

Optocoupler are the devices , which tends current toflow in one direction.And are used between controller and relay section ,to prevent controller from high voltage.

One way direction of current


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560E

6Q

+12v

2

Q

1

2 3

R

1

2

BC547

+12V

BC547

1IR LED

2LED 41483

1

2

3

0

4.7K1MCT2E

Vcc3PIN BASE

input from P3.3

RELAY SECTION

RELAY SPDT

35

412

R

3

560 E

44.7K5


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//P rogram to ON and OFF relay //

# include

Sbit relay1= P1^2;Sbit relay2= P1^3;

void delay(){int i;for(i=0;i


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B uzzer Interfacing

A buzz er is an audio signalingdevice, which may bemechanical, electromechanical or electronic.

Typical uses of buzzers includealarms, timers and confirmation of user input such as a mouse clickor keystroke.


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While interfacing it uses single bit of controller.

BC547 transistor is used to provide switching of buzzer.


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//P rogram to ON and OFF buzzer //

# include

Sbit buzzer= P1^4;

void delay(){int i;for(i=0;i


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D C Motors

T he most common actuator in mobileroboticssimple, cheap, and easy to use.come in a great variety of sizes, to

accommodate different robots and tasks.


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Principles of OperationD C motors convert electrical into mechanicalenergy.They consist of permanent magnets and loops of

wire inside.When current is applied, the wire loops generate

a magnetic field, which reacts against the outsidefield of the static magnets.

The interaction of the fields produces themovement of the shaft / armature.Thus, electromagnetic energy becomes motion.


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Pulse Width Modulation

Pulse width modulation is a technique for reducing the amount of power delivered to a

DC motor.Instead of reducing the voltage operating themotor (which would reduce its power), themotor's power supply is rapidly switched on

and off.The percentage of time that the power is ondetermines the percentage of full operating

power that is accomplished.


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PWM

75

50

25


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/***P rogram to run dc motor with 50% duty cycle ***/

#include

Sbit motor = P0^0;

void delay(){int a;for(a=0;a


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Stepper motor

A stepper motor is an electromechanical devicewhich converts electrical pulses into discretemechanical movements .


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Working


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/********P rogram to run stepper motor inclockwise **********/

#include

void delay(){int a;for(a=0;a

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Rel Buzz + Motors