KBPC3510W Single phase bridge rectifier

Rectifiers

Many of the devices that we use today work on DC power. But the power supply to our homes is in the form of AC. So how do those devices handle the AC supply, and still work properly? Well, this is done with the help of some very fundamental electronic devices called Rectifiers whose function is to convert bidirectional current into the unidirectional current. This unidirectional current is still not constant and needs to be passed through filters containing capacitors or inductors which level the current to almost a constant value.

There are two types of rectifiers:

• Half-wave rectifier: As the name itself suggests, a half-wave rectifier allows only half portion of the current cycles to pass through the load while the other half portion is lost. As a result, these rectifiers have poor efficiency.
• Full-wave rectifier: Full-wave rectifiers are those rectifiers that are capable of harnessing both positive and negative cycles of the current and are thus, far more efficient than half-wave rectifiers. Full-wave rectifiers are again of two types i.e. Center-tap rectifiers and Bridge rectifiers. The bridge rectifier, however, is more efficient and is used in most of the places.

Bridge rectifiers

A basic bridge rectifier circuit consists of four general-purpose semiconductor diodes connected together in a square-like form. One pair diodes on the opposite sides is active during one half-cycle and the other pair is active during the other half-cycle. This arrangement of four diodes now comes embedded on a single chip as a single-phase bridge rectifier. Two of the four terminals are for the input AC current while the other two are for the unidirectional varying current. These bridge rectifiers come in cylindrical, cubic, or some other packages. Some of them may even have metallic cases to help radiate heat in high power applications.

Some important parameters/terms associated with single-phase bridge rectifiers:

• Peak inverse voltage- This is the peak reverse voltage that the bridge rectifier can withstand without breakdown or getting permanently damaged. This can go up to 1000 V for some rectifiers.
• RMS reverse voltage- This is the maximum Root Mean Square (RMS) voltage that can be applied across voltage during normal operating conditions without permanently damaging it.
• Forward voltage drop- This is the voltage drop that is observed across the diode in forward conduction.
• Average rectifier output current- This is the maximum allowed average output current that can be safely drawn from the rectifier.
• Non-repetitive forward surge current- This is the peak forward current that the rectifier can safely withstand provided that the peak current lasts for very short durations.
• Peak reverse current- It is the peak reverse current which leaks through the rectifier. Generally, they are very small and measured in µA and mA.