AC → DC: how a power supply makes DC

Your wall gives AC. Your phone needs DC. Here's how a power supply turns one into the other ⚡

1. STEP DOWN: a transformer turns 230 V AC into 12 V AC (peaks of about 17 V).

2. FLIP: a diode lets current pass only ONE way. 4 diodes in a bridge flip every negative half UP, so you get bumpy DC (about 15.6 V, because 2 diodes each drop ~0.7 V).

3. SMOOTH: a big capacitor (1000 µF) charges at every bump and fills the gaps between them. Only about 1 V of ripple is left.

4. LOCK: a 7805 regulator takes that ~15 V and gives a dead-steady 5 V. Our LED is happy!

The AC is shown slowed down (real: 50 Hz). Phone chargers use a smaller, faster switch-mode version, but the idea is the same.