Bridge RectifiersA bridge rectifier is an array of semiconductor diodes configured as a bridge that acts to change AC (alternating current) to full-wave pulsating DC (direct current). It is used in many electronic devices including laptop computers, cellular phones and PDA's. Depending on how you're viewing the electronic component, the four diodes form a square or diamond pattern. In a single-phase bridge rectifier, there are four diodes; in a 3 phase bridge rectifier, there are six diodes.
When AC current is connected across one diagonal, DC current is available across the other diagonal. The four diodes allow full-wave rectification without the need for a center-tap on the transformer.
The diode bridge circuit is also commonly referred to as a Graetz circuit after it's inventor, Leo Graetz, a German physicist.