Capacitors
3. The Charge-Up Pause
Now, let’s introduce a sneaky component called a capacitor. A capacitor stores electrical energy, like a tiny rechargeable battery. When you first connect a capacitor into a circuit, it starts charging up. During this charging phase, there is current flowing, albeit a decreasing current.
However, once the capacitor is fully charged, it effectively blocks the flow of current. It’s like a reservoir that’s full to the brim; no more water can enter. At this point, in a DC (direct current) circuit, the current through the capacitor becomes zero.
This zero-current state is important in many electronic applications. Capacitors are used to filter out unwanted signals, smooth out voltage fluctuations, and even store energy for brief periods of time. Theyre the unsung heroes of the electronics world, quietly doing their job of blocking DC current when fully charged.
Think of it as a gate that slowly closes as it fills with electrons. Initially, the gate is open, allowing a rush of electrons (current). But as the gate fills (the capacitor charges), it gradually closes, restricting the flow until its completely shut, and no more electrons can pass (zero current).