Bridge rectifiers are discrete semiconductors as they have a single semiconductor device i.e. a diode and are the opposite of an integrated circuit semiconductor which has various devices on a single piece of semiconductor. The diode bridge circuit was invented in 1895 and Leo Graetz designed a similar circuit so they can also be known as a Graetz circuit or Graetz bridge.
A bridge rectifier is built out of 4 or more diodes that are arranged in a specific configuration: the namesake bridge. This diode bridge is able to convert an input of alternating current (AC) into direct current (DC), a basic function for most electronic devices. It also provides the same output polarity for either input polarity. These devices work with a two-wire AC input, have two diode drops in their design and offer full wave rectification.
Bridge Rectifiers are commonly used in power supplies that provide necessary DC voltage for the electronic components or devices and are found in various applications such as home appliances and white merchandise. Also such devices are popular with electronic hobbyists who enjoy constructing circuits.
Rectifiers are usually classified into single phase and three phase, and then split again into uncontrolled, half controlled and full controlled rectifiers. They come in various package and mounting types including screw mount, surface mount and through hole.
Advantages of Bridge rectifiers
• A high peak inverse voltage (PIV) which is ideal for high voltage applications
• A high transformer utilisation factor
• Constructed with or without a transformer – does not need a centre tap transformer
Disadvantages of bridge rectifiers
• More expensive than other rectifiers as it requires four diodes
• Not ideal when a small voltage is required to be rectified
Since bridge rectifiers are discrete devices, some of them need to be purchased along with other devices to achieve the desired functionality for which they are intended. For some engineering needs, the ability to purchase discrete semiconductors makes prototyping and production affordable.