# HUM: Step-Up modul with the XL6009 (Boost Converter)

You are a beginner with Croduino. Or electronics? A specific module caught your eye, but you do not know how to use it? Do not worry, HUM is here for you! How to Use Module (HUM) is a blog tutorials series by e-radionica where you will find all you need in order to begin working with your favorite module. Tutorials include: technical characteristics, work principle, instructions on how to connect module with Croduino and the basic code. Everything else is left to your imagination.

## Introduction

We believe that, so far, you have already made a few of your own projects with our Croduino board. For each project, no matter how complicated, you had to connect Croduino with the USB cable in order for your whole project to be connected to an electric energy source and work successfully. Believe it or not, it is not the only way to connect Croduino with a current source. Using DC-DC converters (to be more precise, Step-Up modules), it is possible to connect Croduino with a battery or a voltage source of less than 5V, which Croduino receives through USB cable. How is it possible? Below is a more detailed explanation of the module itself and its work principle.

Characteristics:
• Input voltage: 3-32 V
• Output voltage: 5-35 V (adjustable)
• Input current: (max) 10A
• Efficiency: more than 94%
• Dimensions 43 x 21 x 14 mm

## How does a boost converter work?

Step up boost converter is a DC-DC voltage converter and its main characteristic is the fact that the output voltage is higher than the input voltage. It can very easily and efficiently increase the voltage of a power source to the desired value. Depending on the characteristics, it is possible to increase the input voltage by as much as 10 times! Power source can be anything from battery, solar panel, DC power supply, AC/DC converter etc.

In theory, the step up converter consists of a simple coil, switch, capacitor and diode connection. The image above shows the general scheme of the step up converter. We can observe the resistor, in this case, as a load in the circuit.

Let's imagine a situation when the circuit switch is open (not connected). When we connect the voltage source to the circuit, current will flow through the coil that converts a part of energy into magnetic energy. That same current flows through the diode that ensures the correct current direction and results in the capacitor being charged and the load having an ensured voltage source. Let's now imagine that we have closed the switch. What will happen? The capacitor will remain charged because of the diode which prevents it from emptying, but what about the coil? The coil is connected with the voltage source into the short circuit and after some time, it would burn out. This can be prevented by closing the switch for a very short period of time, short enough not to cause a short circuit, but long enough for magnetic field not to disappear. Now the coil will convert the part of magnetic energy back into the electric energy and "add" voltage to the circuit. This way, the resistor (load) will have the ensured electric energy source of higher voltage than the one connected in the circuit.

Briefly and simply explained, it is the basic work principle of the step up converter. Using the coil connected in a simple, but smart way, we increase the voltage in the circuit. As far as the switch is concerned, mainly MOSFETs which quickly open and close the circuit (up to 400kHz) are used. This module uses the XL6009 regulator which contains the MOSFET and an oscillator which generates interruptions in the MOSFET. From the technical characteristics of the regulator itself, we can see that the conversion efficiency can reach values up to 94%! This means that there is almost no energy loss when we use this converter.

## How to connect it?

Connecting the module to Croduino or any other load is very simple. The module contains 4 connectors symbolically named IN+IN-OUT+ and OUT-. It is necessary to connect the power source (e.g. battery) to the "IN" connectors in the right way where the plus (+) of the battery should be connected to "IN+", and the minus (-) to the "IN-" connector. "OUT +" and "OUT-" are the output voltage connectors which can be connected to Croduino. Before connecting with Croduino, it is necessary to connect the multimeter to "OUT +" and "OUT-" and turn the small trimmer (small "screw" on the blue component) to adjust the value of the desired output voltage. By turning it in one direction, we increase the voltage and, by turning in the other direction, we reduce the voltage. For this example, we will set the output voltage value to 7.5V. We connect "OUT+" to the VIN pin and "OUT-" to one of the GND pins. After that, Croduino will work the same way as if we have connected it with the USB cable. The picture below shows the exact connection of the module.

In the same way, you can implement this module into any project that requires a voltage of a certain value using batteries or any voltage source that is too low for your needs. Because of its high efficiency and simplicity of use, we believe that this module will certainly be useful in your future projects.