Direct current

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Di­rect cur­rent is elec­tric cur­rent with a con­stant di­rec­tion of flow. The di­rec­tion of move­ment of di­rect cur­rent (DC) re­mains con­stant over time.

The different types of current

A dis­tinc­tion is made be­tween con­stant di­rect cur­rent, in which the cur­rent strength is al­ways the same, and pul­sat­ing cur­rent, in which the cur­rent strength changes pe­ri­od­i­cal­ly. A cur­rent whose di­rec­tion changes pe­ri­od­i­cal­ly, on the oth­er hand, is re­ferred to as al­ter­nat­ing cur­rent (AC). A com­bi­na­tion of these two types of cur­rent is called mixed current.

Where is direct current used everywhere?

Ba­si­cal­ly, the glob­al en­er­gy sup­ply is pro­vid­ed by al­ter­nat­ing cur­rent. The pow­er plants feed their elec­tric­i­ty in­to the pow­er net­work as al­ter­nat­ing cur­rent. The elec­tric cur­rent we draw through our sock­ets is there­fore not di­rect cur­rent. How­ev­er, the de­vices we use in our dai­ly lives need di­rect cur­rent to func­tion. To ac­com­plish this, the de­vices con­vert the al­ter­nat­ing cur­rent they re­ceive in­to di­rect cur­rent us­ing rec­ti­fiers. Un­for­tu­nate­ly, this con­ver­sion gen­er­ates heat and a loss of pre­vi­ous energy.

Advantages and disadvantages of direct current

Di­rect cur­rent does not re­quire trans­form­ers to trans­mit it over the long dis­tance be­tween the pow­er sta­tion and the con­sumer. Al­so, there are much few­er loss­es dur­ing trans­mis­sion than with al­ter­nat­ing cur­rent. The def­i­nite dis­ad­van­tage of di­rect cur­rent is the great ef­fort and thus the cost of gen­er­at­ing a high di­rect voltage.

Who invented direct current?

Thomas Edi­son is con­sid­ered the in­ven­tor of di­rect current.

What is electricity?

Elec­tric cur­rent in physics is the move­ment of elec­tric charge flow­ing through an elec­tri­cal con­duc­tor in­to a cir­cuit. It is treat­ed in elec­tric­i­ty theory.

The calculation of current

To know how much elec­tric cur­rent is flow­ing, we need to cal­cu­late the elec­tric cur­rent in­ten­si­ty (I). De­fined is as the amount of charge (Q) di­vid­ed by the time (t). If the elec­tric cur­rent in a cir­cuit is de­ter­mined, the volt­age (U) through the re­sis­tance of the con­duc­tor ® can al­so be taken.

What effect can current cause?

  • Heat ef­fect
  • Light ef­fect
  • Mag­net­ic effect
  • Chemis­che Wirkung
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