How does a rectifier circuit work
This waveform shape is now much closer to a pure DC voltage waveform. The waveform can be further improved by using other types of filters such as an L-C filter and pie filter. The bridge rectifier just discussed is a single-phase type, however, it can also be extended to a three-phase rectifier. These two types can be further classified into full controlled, half controlled, or uncontrolled bridge rectifiers. The circuit that we just discussed is uncontrolled since we cannot control the biasing of the diode, but if all the four diodes are replaced with a thyristor , its biasing can be controlled by controlling its firing angle via its gate signal.
It results in a fully controlled bridge rectifier. In a half controlled bridge rectifier, half of the circuit contains diodes, and the other half has thyristors.
Your Name required. Your Email required. Ripple factor: — It is an Important factor which decides the quality of the rectifier. Advantages and Disadvantages of Half wave Rectifier. Advantages 1. Disadvantages 1. Center tap Full wave Rectifier. To utilize to the negative half cycle of Ac supply to Diodes are connected with a special type of Transformer called as centre tap Transformer.
In this transformer middle terminal is tapped so that the upper terminal A and lower terminal B becomes opposite in phase. Center tap full wave Rectifier and its wavefoms. Working details. It is difficult to locate the centre tap winding. The cost of centre tap Transformer is more than normal type of transformer. The DC output voltage is smaller as each diode utilizes only one half of sec. Bridge full - wave Rectifier. The center tap transformer is eliminated in the bridge rectifier by using four diodes connected in the form of bridge.
As four diodes are connected in bridge this rectifier is called as a bridge full wave rectifier. The secondary of transformer is connected diagonally opposite end of the bridge. The load resistance R L is connected between other two ends of bridge.
Advantages and Disadvantages. It does not require center tap transformer, hence it is low cost rectifier. Peak Inverse voltage of each diode is only peak voltage of secondary. The output voltage is twice that of center tap rectifier for same secondary voltage of transformer. It requires four diodes. As during each half cycle of AC input two diodes are conducting therefore internal voltage drop is 1.
Comparison of all Rectifiers. Ripple Frequency F in 2 F in 2 F in 6. Rectifiers in power supply circuits convert AC to DC from different power supplies. This is useful as DC is generally sent across long distances before it is converted to AC for household electricity and electronic devices. These technologies make great use of the bridge rectifier that can handle the change in voltage.
After studying physics and philosophy as an undergraduate at Indiana University-Bloomington, he worked as a scientist at the National Institutes of Health for two years. He primarily performs research in and write about neuroscience and philosophy, however, his interests span ethics, policy, and other areas relevant to science.
How Does a Rectifier Work? What Is a Flyback Diode? What Are the Functions of a Zener Diode? How to Calculate Ohms to Microfarads. Uses of a Diode. What Is a Varactor Diode? How Do Batteries Work? Uses of Photocells. What Are the Uses of Direct Current? Since the output after the diode bridge rectifiers is of pulsating nature, and for producing it as a pure DC, filtering is necessary.
Filtering is normally performed with one or more capacitors attached across the load, as you can observe in the below figure wherein smoothing of the wave is performed. This capacitor rating also depends on the output voltage. The last stage of this regulated DC supply is a voltage regulator that maintains the output voltage to a constant level.
Suppose the microcontroller works at 5V DC, but the output after the bridge rectifier is around 16V, so to reduce this voltage, and to maintain a constant level — no matter voltage changes in the input side — a voltage regulator is necessary.
As we discussed above, a single-phase bridge rectifier consists of four diodes and this configuration is connected across the load. When the voltage, more than the threshold level of the diodes D1 and D2, starts conducting — the load current starts flowing through it, as shown in the path of the red line in the diagram below.
During the negative half cycle of the input AC waveform, the diodes D3 and D4 are forward biassed, and D1 and D2 are reverse biased. Load current starts flowing through the D3 and D4 diodes when these diodes start conducting as shown in the figure. We can observe that in both cases, the load current direction is the same, i. Thus, by the usage of a bridge rectifier, the input AC current is converted into a DC current. The output at the load with this bridge wave rectifier is pulsating in nature, but producing a pure DC requires an additional filter like a capacitor.
The same operation is applicable for different bridge rectifiers, but in the case of controlled rectifiers thyristors triggering is necessary to drive the current to load. Bride rectifiers are classified into several types based on these factors: type of supply, controlling capability, bride circuit configurations, etc.
Bridge rectifiers are mainly classified into single and three-phase rectifiers. Both these types are further classified into uncontrolled, half controlled, and full controlled rectifiers.
Some of these types of rectifiers are described below. The nature of supply, i. The Single phase bridge rectifier consists of four diodes for converting AC into DC, whereas a three-phase rectifier uses six diodes , as shown in the figure.
These can be again uncontrolled or controlled rectifiers depending on the circuit components such as diodes, thyristors, and so on. This bridge rectifier uses diodes for rectifying the input as shown in the figure.