AC to DC Converter

What is an AC-DC Convertor

An AC-DC converter is an electrical circuit which transforms (AC) alternating current input to (DC) direct current output. An AC-DC converter is also called a rectifier, it converts the AC input voltage to variable DC output voltage, then optimizes it using a filter to achieve an unregulated DC voltage.

AC-DC converters have become relevant in recent years because of the advancement of power electronics technology. This power electronics technology operates and controls the flow of electrical power to provide voltage and current in a way that is optimally compatible with end user’s needs.

How AC-DC Converter Works

The AC-DC power supply has the following components used in its functioning:

Transformer

It changes the AC voltage to the level required by the device being supplied.

Rectifier

When converting AC voltage to DC voltage, voltage will be rectified using diodes which transform AC sinusoidal waves to positive peaks using a rectifier.

Filter

This is the process of removing ripples from the rectified output. The filter maintains a clean and steady output voltage that matches the original peak AC input wave.

Regulator

After this waveform is rectified and filtered, it is then passed through a regulator which oversees keeping the output at a constant level despite in any varying in the input voltage.

Requirements for an AC-DC Converter

Thew requirements for an AC-DC convertor include:

• Compact Size
  Latest smart devices are increasingly lightweight, compact and easy to install in their design. Thus AC-DC converter manufacturers have to stay on top of this trend.

• High Efficiency
  It is very sought after by manufacturers. AC-DC converters feature high efficiency meaning there is low energy loss during operation.

• Low Standby Power
  They have low standby power usage. This is very significant for some smart home or IoT devices which operate mainly in standby mode, the likes of electric curtains, sensors and door lock systems.

Considerations when Selecting an AC-DC Converter

The following steps will help in choosing the right AC-DC converter.

• Select standard reference voltage in accordance with input voltage range.
• Select output power and type of package depending on the load.
• Select the proper output voltage depending on the load type.
• Select isolation voltage. Isolation may make output and input voltage of converter to be not common grounded.

Types of AC-DC Converters

There are various types of AC-DC converters based on the converting process and output size. Customers can decide what to choose depending on the results to be expected from each type.

Uncontrolled Diode Rectifiers

This rectifier type converts mains AC voltage to a fixed DC voltage. Since the diodes cannot be controlled components these converters are uncontrolled converters because they create a fixed voltage. The input voltage may either be single phase or three phase.

Phase Controlled Rectifiers

These are alike to the uncontrolled rectifiers the only difference being that uncontrolled diodes are substituted by controlled thyristors of devices like SCRs. These also are called phase controlled rectifiers.

Unlike a diode, a thyristor is controlled by triggering it at required instants in order to vary the voltage output. The beginning of thyristor conducting varies the mean output voltage value of the converter.

Capacitive Transformerless Converter

A transformerless converter converts high input AC voltage to the needed low DC output voltage (3V, 5V or 12V) with low output current in milliamps. It is utilized in low power electronics like toys, LED bulbs, and household appliances.

Applications of AC-DC Converters

There are many real life applications which are based on this conversion. AC-DC converters are utilized in consumer devices, industrial process control systems, semiconductor manufacturing equipment, measurement equipment, defense applications and medical devices. For instance in smart homes, power devices use efficient hardware for AC-DC conversion to cut energy losses and achieve noteworthy cost savings.

Advantages of an AC-DC Converter

The following are some of the advantages of AC-DC converters:

• Energy Efficient
  Removes the need for many inverters and converters. Reducing power conversion and reversal also prevents chances of equipment failure. In electric vehicles, AC-DC converters offer fast charging and storing connections.

• Space Saving
  In industrial applications, AC-DC converters are usually lightweight, small, and simple to install. Compact power converters save space for the device making the whole device more compact.

• Cost Saving
  AC/DC converters satisfy low power operation during lengthy standby times. Its high energy saving capacity makes it appropriate for industrial applications and home appliances.