Aigek Electrical Science | How to convert AC into DC?

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Aigek Electrical Science | How to convert AC into DC? [Copy link]

I believe that many of my friends have this question when studying electricity or using a wiring harness tester: how does alternating current become direct current?

First, let's understand the basic concept, what is direct current (DC)?

What is Direct Current (DC)

Refers to the current whose magnitude (voltage) and direction (positive and negative poles) do not change with time (within a relative range)

What is Alternating Current (AC)

Refers to the current whose direction changes periodically with time, and the average current in one cycle is zero. Unlike direct current, its direction changes with time, while direct current does not change periodically.

To answer this question, in addition to understanding the definitions of DC and AC, you also need to know the following concept:

diode

A diode is an electronic device made of semiconductor materials (silicon Si, selenium Se, germanium Ge, etc.). Here we emphasize its unidirectional conductivity, that is, when a forward voltage is applied to the anode and cathode of the diode, the diode is turned on. When a reverse voltage is applied to the anode and cathode, the diode is turned off.

Based on the unidirectional conductivity of the diode, four diodes can be combined into a rectifier bridge, which can convert AC into DC.

Because the direction of AC current changes with time, we need to analyze two more situations:

Positive on top and negative on bottom:

Positive below and negative above:

The positive pole of the alternating current can be connected to the positive pole of the output in different cycles, thereby converting the alternating current into direct current. At this time, the alternating current is:

Such direct current cannot be used either, because the magnitude of the current is constantly changing. We also need to connect a capacitor in parallel to make the output current stable.

In summary, to put it simply, the conversion of AC to DC is:

AC power - rectification (combining several diodes to convert positive and negative voltages into unidirectional ones) - filtering (making the waveform smooth) - voltage regulation (fixed output) - DC power.

The above is the popular science content of electrical knowledge related to the wiring harness tester, which is how the alternating current is converted into direct current. For those who are interested in the wiring harness wire tester, you can pay attention to the official website of Aigtek Antai Electronics, where more exciting content is waiting for your discovery! ~