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Meaning of the term "Relay"

#1 13-Dec, 2011 06:54 PM
Dinesh
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Basically i don't understand what a relay means.Can anyone describe about it or give the source so that i can learn about it.
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#2 13-Dec, 2011 07:18 PM
Rohit B.D.
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A relay is an electromechanical device that is used to switch a high-current or high-power load (or appliance) using a low current or low power control voltage. For automobiles, they are ubiquitous and found almost everywhere (i.e., control every electrical thing) - lamps, horn, radiator fan, AC clutch, turn indicator, fuel pump and so on.

See this: http://en.wikipedia.org/wiki/Relay




S = k.I^2, where S is the amount of stupidity a species possesses, I is the intelligence the species has and k is the universal constant of stupidity.
Last Updated: 13-Dec, 2011 07:23 PM, by rohit.b.d.
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#3 13-Dec, 2011 07:22 PM
Dinesh
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Thanks Rohit. SO you mean the battery which is in the car has an less out power compared to used by the appliances ( lamps, horn etc..) in the car.
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#4 13-Dec, 2011 07:28 PM
Rohit B.D.
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No - a relay is basically a sort of "agent" between the driver (the switch/control/knob that the user operates) and the particular electrical part being controlled. For example, when you press the horn on the steering - this horn is a switch, but it cannot (and is not meant to) carry a large current. When you press the switch the small current in it flows through the relay thereby energising it. When the relay energises, its contacts (which are designed to carry large current) close thereby supplying current to the horn - the horn needs a much larger current to operate than the relay itself. If the switch is used to directly control the horn, it will soon get damaged due to the large current that the horn needs (or consumes) as it operates.




S = k.I^2, where S is the amount of stupidity a species possesses, I is the intelligence the species has and k is the universal constant of stupidity.
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#5 13-Dec, 2011 07:41 PM
Dinesh
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It was real good explanation. Thanks. Now i'm able to understand. So its an indirect switch using a smaller amount of current to operate the appliances.
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#6 13-Dec, 2011 07:46 PM
Rohit B.D.
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Exactly!




S = k.I^2, where S is the amount of stupidity a species possesses, I is the intelligence the species has and k is the universal constant of stupidity.
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