The Complete Guide to Rectifiers For Electrical & Engineering Beginners


Before we get into the many types of rectifiers, it’s important to define what a rectifier is. A rectifier is a diode that transforms alternating current (AC) into direct current (DC) (DC). DC only flows in one direction, whereas AC flips direction on a regular basis. Rectifiers are devices that enable electricity to flow in just one direction.

Rectifiers convert alternating electricity to the high-quality direct voltage required by telecom equipment. Traditional telecommunications equipment requires DC input power, whereas mains power is supplied by AC. Multiple rectifiers convert AC power to DC electricity, allowing these power systems to function.

What is Rectifier?

A rectifier is a device that transforms two-way alternating current (AC) into single-directional direct current (DC) (DC). ne555p Rectifiers come in a range of physical shapes and sizes, ranging from vacuum tube diodes and crystal radio receivers to current silicon-based systems.

Half-wave rectifiers are the simplest rectifiers. They function by removing one side of the AC and allowing just one direction of current to pass through. Half-wave rectifiers are inefficient converters because half of the AC power input is wasted. A full-wave rectifier, which employs both sides of the AC waveform, is a more efficient conversion option.

Rectifiers may be used to change network systems and can be found in a number of devices. They are classified in a variety of ways based on variables such as the kind of supply, the bridge arrangement, and the components employed. Rectifiers may be divided into two categories: single phase and three phase. They can then be divided into half wave, full wave, and bridge rectifiers by drilling down another level.

Different Types of Rectifiers

Rectifiers are clearly important components of any network system, but we must go deeper to comprehend the many varieties. Different rectifiers are utilized depending on the context and the system in which they are used. Single phase and three phase are the top two levels, indicating how many diodes are utilized in the circuit. Then there are half wave, full wave, and bridge rectifiers, which all have an impact on the number of half cycles generated. Let’s take a closer look at each kind to see which rectifier should be utilized.

Single Phase & Three Phase Rectifiers

One phase AC electricity is fed through single phase rectifiers. The constructions are straightforward, using only one, two, or four diodes (dependent on the type of system). This implies the single phase rectifier only produces a limited quantity of power and has a lower transformer utilisation factor (TUF). For conversion, a single phase rectifier employs just the secondary coil of a single phase transformer, and diodes are connected to the secondary winding of the single phase transformer. This results in a large ripple factor.

Three-phase AV power is fed through three-phase rectifiers. Three or six diodes are required for each phase of the transformer secondary winding, and they are linked to each phase of the transformer secondary winding. To lower the ripple factor, three phase rectifiers are utilized instead of single phase rectifiers.

When employing big systems, three phase rectifiers are favored over two phase rectifiers. This is due to the fact that they can supply a lot of power and don’t need any extra filters to lower the ripple factor. Three phase rectifiers are more efficient and have a higher transformer utilization factor as a result of this.

Uncontrolled & Controlled Rectifiers

When just diodes are employed in the circuit, it is referred to as an uncontrolled rectifier. So far, all of the rectifiers we’ve looked at have been uncontrolled rectifiers. Thyristors are used to regulate the DC output in controlled rectifier circuits. Because diodes can only be on or off, they’re employed when current has to be regulated more precisely. Controlled rectifiers provide continuous control and ensure that no power is wasted.

Bridge Rectifiers

Bridge rectifiers are commonly used in power supplies to supply components with direct current voltage. Four or more diodes, as well as a load resistor, are used.

Only two of the four diodes are connected in series, enabling electric current to flow throughout each half cycle. The diodes are thought to function in pairs, with one pair allowing current to flow during the positive half of the cycle and the other half allowing current to flow during the negative half of the cycle. The input alternating current is applied to two terminals, while the output direct current is created by connecting the resistor inductor to the other two terminals.

Bridge rectifiers allow electric current to flow during the input AC signal’s positive and negative half cycles. These circuit layouts do not necessitate the use of pricey center tapped transformers.

Half Wave & Full Wave Rectifiers

Half wave rectifiers turn a half cycle of AC input into pulsing DC output. This permits half of the AC input cycle to pass while blocking the other half. It is possible for the half cycle to be either positive or negative. Because just one diode is employed, it is the simplest rectifier. Figure 1 displays a positive half-wave rectifier, whereas a negative half-wave rectifier shows the diode reverse biased (facing the opposite way). The ripple factor is significant due to the pulsing nature of direct current. Half wave rectifiers are not regarded efficient as a result, and they frequently require filters to decrease ripple factor.

Both (positive and negative) half cycles on the AC input are converted into pulsing DC output by full wave rectifiers. These circuits employ a center tapped transformer, which is linked across the centre of a transformer’s secondary winding, as seen in figure 2 (below). These transformers split the incoming AC into two parts: positive and negative. As a result, full wave rectifiers are thought to be far more effective than half wave rectifiers since the ripple factor is substantially smaller. Furthermore, because both cycles are allowed at the same time, no signal is wasted.


In conclusion, a rectifier is a device that transforms alternating current (AC) into direct current (DC) (DC). A rectifier is similar to a one-way valve in that it only enables electricity to flow in one direction. Rectification is the process of converting AC current to DC current. Solid-state diodes, vacuum tube diodes, mercury-arc valves, silicon-controlled rectifiers, and several other silicon-based semiconductor switches are examples of rectifiers.

The rectifier’s principal function is to convert AC power to DC electricity. Rectifiers are found in practically all electronic equipment’s power supply. The rectifier is generally connected in series with the transformer, a smoothing filter, and potentially a voltage regulator in power supply.


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