Does a Diode Block AC or DC? The Core Question
2. AC vs. DC
Before we dive into the diode's blocking preferences, let's quickly revisit AC and DC current. DC, or direct current, flows in one direction only, like a river flowing steadily downstream. Think batteries: they provide a constant, unidirectional flow of electrons.
AC, or alternating current, on the other hand, is like a tide, constantly changing direction. It oscillates back and forth, typically in a sinusoidal pattern. This is the type of current you get from your wall outlet — it changes direction many times a second (60 times in the US, 50 in Europe).
Now, back to our diode bouncer. The diode happily allows DC current to pass through, provided it's flowing in the correct direction (forward bias). However, when it comes to AC, the diode's behavior is more nuanced. It doesn't simply block it entirely, but rather allows the positive portion of the AC cycle to pass while blocking the negative portion.
In essence, the diode acts like a rectifier, converting AC into a pulsating DC. It chops off the negative swings, leaving you with a series of positive pulses. This rectified signal isn't smooth DC like a battery provides, but it's a crucial step in many electronic circuits that need to convert AC power from the wall into usable DC power.
