Everything in nature requires a source of energy. Arduino is no different. In the market we can find many different DC power sources, among those most commonly used are batteries, 5V (USB), 12 V and 24 V. Many more exist, but these represent the vast majority.
I had a (technical) problem, where I was using Arduino to cycle a pneumatic cylinder, but in an industrial environment. There I can always find 24 V DC in some corner or another, but 5 V, as Arduino requires is not that common. Hence this sub-project.
- Jameco LM2575T datasheet: https://www.jameco.com/Jameco/Products/ProdDS/894534.pdf
- Texas Instruments LM2575 datasheet: http://www.ti.com/lit/ds/symlink/lm2575-n.pdf
How to step-down 24 V to power up Arduino? There are at least two ways to my knowledge:
The first is inefficient — it heats up a lot. The second is efficient, but it produces some high-frequency noise.
Let’s see, how we can use the second type, LM2575T to make a very cost-effective Arduino power supply.
Bill of materials
For this project you will need the following material:
- LM2575T switching regulator (1 pc)
- 100 µF capacitor (1 pc)
- 330 µF capacitor (1 pc)
- 330 µH inductor (1 pc)
- 1N5819 (also 1N5817) Shottky diode (1 pc)
- PCB or protoboard (1 pc)
All together will put a dent of approximately € 0.46 in your pocket, if you get a great deal. Without the PCB that is.
It doesn’t matter, if you can buy a power supply for Arduino on Aliexpress for less than $1.00, this project is more about making something and being satisfied with yourself. You can also integrate this project with your other projects and get a compact, more professional PCB. Why not trying to sell one of those then?
If you need a cheap and efficient 5 V power supply for your micro-controller, I think the LM2575 is a great choice. It will work much more efficiently than linear voltage regulators, which means less energy consumption and heat loss. This is an easy project, I would say, and I think that you should tackle this yourself, to learn a few basics.