VIDEO ACTIVATED RELAY TO CONTROL THE LOAD

Introduction This simple circuit activates a relay when it senses a composite video signal. This allows the user to use the tuner built into VCR to turn ON and OFF older TVs that are not equipped with a remote. It can also be used to activate surround sound equipment, turn off the room lights, turn on video game consoles, etc.

EMBEDDED SYSTEMS Definition for :- EMBEDDED SYSTEMS A combination of hardware and software which together form a component of a larger machine. An example of an embedded system is a microprocessor that controls an automobile engine. An embedded system is designed to run on its own without human intervention, and may be required to respond to events in real time.

EMBEDDED SYSTEMS

2.BLOCK DIAGRAM

BATTERY An electrical battery is a combination of one or more electrochemical cells, used to convert stored chemical energy into electrical energy. The battery has become a common power source for many household, robotics and industrial applications. Larger batteries provide standby power for telephone exchanges or computer data centers

1N4148 The 1N4148 is a standard small signal silicon diode used in signal processing. Its name follows the JEDEC nomenclature.

1N4007 Diodes are used to convert AC into DC these are used as half wave rectifier or full wave rectifier. Three points must he kept in mind while using any type of diode.

ZENER DIODE

The resistor, RS is connected in series with the zener diode to limit the current flow through the diode with the voltage source, VS being connected across the combination. The stabilised output voltage Vout is taken from across the zener diode. The zener diode is connected with its cathode terminal connected to the positive rail of the DC supply so it is reverse biased and will be operating in its breakdown condition.

BC547 The BC547 transistor is an NPN Epitaxial Silicon Transistor. The BC547 transistor is a general-purpose transistor in small plastic packages. It is used in general-purpose switching and amplification BC847/BC547 series 45 V, 100 mA NPN general-purpose transistors. Whenever base is high, then current starts flowing through base and emitter and after that only current will pass from collector to emitter  

RELAY IT IS A ELECTRO MAGNETIC SWITCH USED TO CONTROL THE ELECTRICAL DEVICES COPPER CORE MAGNETIC FLUX PLAYS MAIN ROLE HERE

Relay Driver ULN2003 ULN is Relay driver application The ULN2003 is a monolithic high voltage and high current Darlington transistor arrays. It consists of seven NPN Darlington pairs that features high-voltage outputs with common-cathode clamp diode for switching inductive loads. The collector-current rating of a single Darlington pair is 500mA. The Darlington pairs may be paralleled for higher current capability.