The letters DC in electronics are an abbreviation for direct current. A direct current is an electrical current that travels in one direction only, which is in contrast to the alternating current (AC), which travels in both directions(but not at once: as the name suggests, it alternates its direction). In a D/C circuit, electrons emerge from the negative pole and move towards the positive pole.
D.C. current is induced by moving a coil of wire through a magnetic field. You can do this quite simply at home with a length of copper wire (you’ll need heaps) and a bar magnet. First make a coil by wrapping some of the copper wire twenty or so times around something reasonably fat – a vivid marker will do. Keep the ends free and connect them to an ammeter so you can prove that you really have generated some DC. Now feed a bar magnet through the coil and hold it steady. Once you have done this, move the coil. You should see the needle on the ammeter surge as you induce DC in the circuit. To generate AC as opposed to D/C, then move the magnet back and forth, keeping the coil still. And if you took physics in your final year of secondary school, you probably had to do this as a classroom exercise.
The same sort of principle applies in cars. In automotive electronics, it is often necessary to create many AC and DC voltages at the same time. There are many types of electronic modules in motor vehicles today, especially with the ever-increasing amounts of electronic circuitry within modern automotive systems.
We hope that helps answer the question ‘What is What is a DC?’!
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