====We can learn about what is ac source?,inventor of ac source and advantages-disadvantages of ac source in previous post.In this Post we can learn about dc source and its advantages and disadvantages.click here..
Definition
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====Now lets go know about its definition given below....> "DC source is unidirectional flow of electric charge"..
>"DC source flow in one direction and constant magnitude"
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History of DC current....
> First dc current produced by using voltaic pile.but at that time its not efficient
> After scientist Ampere was discovered dc current flow in only one direction.Positive to negative.
> Scientist PIXXI produced direct current by using dynamo contact with commutator.
> Finally In1880 thomas alva edision install dc power station and dc power transmit in usa.
> So that Thomas alva edision known about Father of dc source.
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====Battery is best examples for dc power supply.
====Generally direct current converted from ac power supply by using rectifier circuit between ac source and dc circuit.
==== Direct current converted into ac current by using inverter and motor generator set.
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= wave form of direct current shown below...
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| direct voltage with respect to time |
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====Now lets go we can take example of battery and load.see how dc current work.
====Since one electron is moving back along the wire at the same time another is moving forward, no net charge is transported along the wire.
====If a battery is hooked to the ends of the wire, the electrons get pushed all in the same direction along the wire. So any single electron takes a long time to get all the way around the circuit.
==== There are so many electrons that they bump into one another, like dominoes, and there is a net shift of electric charges around the circuit that can happen at speeds up to the speed of light.
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Application of DC source
(1) Domestic
(2) Automotive
(3) Telecommunication
(4) High voltage power transmission line
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Advantages of dc source
(1) The number of conductors required, mainly one or two, is less as compared to ac transmission.
(2) DC is easier for electrical devices to use directly.
(3) Easier to store in battery while ac source can not be stored in any equipment.
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Disadvantages of dc source
(1) DC source can not be transmitted at long distance.
(2) losses very high in transmission line.
(3) HVDC to AC grid connection very complex.
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