DC-DC Converters: Buck, Boost, and Buck-Boost

Overview:

DC-DC converters are like us, some people need to know when to step down gracefully and be humble or step up their game and be better. In this tutorial, we will be comparing and testing these DC-DC converters, namely, buck, boost, and buck-boost converters.

Components Used:

Application Discussion:

A DC-DC converter is a device that converts a direct current (DC) source from one voltage level to another. Buck, boost and buck-boost DC-DC converters are widely used for power supply design. They are popular for simplicity, low cost, and high efficiency.

BOOST CONVERTER

The Boost Converter is a DC-DC Converter with an output voltage greater than the source voltage and it usually used in lighting systems and electric vehicles. A boost converter is sometimes referred to as a step-up converter because it 'steps up' the source voltage or, in other words, the output voltage is more than the input voltage.

Boost converters deliver higher voltage and lower current. Most boost converters are also used in regulated power supplies (means that the regulator ensures the output voltage will always stay at the rated value of the power supply, regardless of the current that the device is consuming).

Testing Boost Converter

The output of the boost converter on the specification sheets can be 2.5V-6V volts to provide 5V and 1A output.

Arduino Uno was used for the testing of the component then setting the power supply to a minimum input voltage. The operating voltage of Arduino is 5V and by using a boost converter, we can see here that it can power up Arduino at 2.5V.

BUCK CONVERTER

Many electronic systems, such as battery chargers and power amplifiers have Buck converters. Buck converter is a DC-DC converter that converts high voltage to low voltage and is sometimes referred to as a 'step-down' converter as it steps down the input voltage.

Buck and boost converters also different in terms of the voltage and current, where Buck converter provides lower voltage and higher current. Most of the buck converters are also used in unregulated power supply (unregulated power supplies provide a constant amount of power (V x A), the output voltage will decrease as the output current increases).

Testing Buck Converter

On the specification sheets, buck converter’s input can be at 6-24 V to provide an output of 5V and 3A.

I used my laptop’s cooling fan to test the buck converter, the operating voltage for the cooling fan is only at 5V -9 V, the buck converter works as I set the voltage at maximum voltage yet still managed to turn on the air-cooling fan without any damage to the device.

 

BUCK-BOOST CONVERTER

A Buck-Boost converter is a type of switched mode power supply that combines the Buck converter and Boost converter principles in a single circuit. The primary goal of the buck-boost converter is to receive an input DC voltage and output at a different level of DC voltage, either by reducing or increasing the voltage as required by the application.

 

On the specification sheet, the range for the input is 5V - 35V and the output can be 1.2V-35V. You can control and adjust the output of the buck-boost converter by simply turning the screw clockwise or counter counter-clockwise.

Testing the Buck-Boost Converter

Clockwise if higher voltage is required.

 

Counter-Clockwise if lower voltage is needed

 

*Basically:

  • Buck converter reduces voltage, and the output voltage is lower than the input voltage.
  • Boost converter increases voltage, and the output voltage is higher than the input voltage. 
  • Buck-Boost converter is a combination of a buck and boost converter. The output voltage can be higher or lower than the input voltage. 

You can purchase all of the DC-DC Converters mentioned in the Createlabz Store! CLICK HERE.

Conclusion:

This tutorial was able to compare and test the three different DC-DC converters. DC-DC converters are widely used to efficiently produce a voltage from a source that may or may not be well controlled or may not be constant.
Voltage must be kept within a set range in order for the power system to operate properly and safely. If the voltage is too high, the equipment may be damaged, if it is too low, the equipment may operate poorly or stall.

Reference:

TDK-Lambda Americas Blog: What are buck, boost and buck-boost DC-DC converters? (power-topics.blogspot.com)

BoostBoost converterBuckBuck converterBuck-boostBuck-boost converterConvertersDc-dcDc-dc convertersStep downStep upVoltage

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