Smart Distributed DC Power Management (5V DC 30W) 6th iter.

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The problem

Now that a universal cable connector is a reality, the USB-C, the next big change is on how to remove all those power converters and inverters at home, vis-a-vis, " power bricks". These can waste up to 30% of electricity "converted". In my professional opinion, the best and only way to do it is by adding a small mechanical switch, however, mechanical relays consume too much power (around 200mW).

The idea

To solve the 30% wasted on conversion, the only way is, to reduce to the minimum "power bricks" needed /required at home or office. This can be achieved by installing several electricity lines in parallel connected to each power outlet in a room, nowadays with built-in USB connectivity. USB-C power delivery is capable of managing automatically powerlines up to 20V 5A DC meaning all indoor LED illumination, laptop computers, smartphones & tablets, and all smart devices including big OLED TV screens.

One possible solution to solve electricity consumption in standby mode is by using a micro stepped DC motor connected to simple electronics with "deep sleep" with or without wireless capabilities. This way it is possible to lower consumption to 2-8uA @ 3.3V DC.

The main objective of this project is to negotiate power delivery to each individual power outlet socket from a master Distributed Power Management System. Is possible to achieve this using only 2 wires where one of them is used for both power and data transmission. There's a really good one-wire library here that enables one to build such a power delivery setup.

In the last 5th iteration of this project I CNC machined a piece of wood made to fit my existing balcony window wood frame, where I assembled the solar cells into four solar arrays, each for a maximum output of 5V 5.2A DC. Here's the link to the article: https://www.hackster.io/mtpsilva/low-power-home-dc-electrical-system-5th-iteration-f90f3f

Smart Distributed DC Power Management (5V DC 30W)

The Smart Distributed DC Power Management and Charging Device I've been designing and prototyping using KiCad has the purpose of charging 5V DC battery walls and power packs from the main 220V AC line at home. The innovation of this power charging device is in the ability to schedule charging to specific times during the day and night according to the price of electricity change. It can be programmed using machine learning to connect to an electricity market data source and calculate the best time to schedule battery charging according to the price variations in the electricity markets.

This hardware electronics I ordered fabrication from Seed Studio Fusion, who are supporting this project by providing their hardware fabrication services cost-free, is intended to be mounted inside the LK-C60 ABS enclosure and installed at the top of the main 220V AC outlet (see the white box enclosure show on the photo for the 3rd iteration of my power wall).

This revision features::

• 4 USB-C with power deliver
• 3 USB-A for fast charging up to 30W
• With 220V AC to DC converter and Power charging scheduler to allow charging only when the electricity price is lower (during the night) using machine learning algorithms
• With a 5.0V DC two-wire connector to allow DC charging from another source (for instance from solar panels)
• With a 5.0V DC two-wire connector to power an indoor main DC line for all 5.0V devices and electronics (smartphones, tablets, or any other) -With individual power consumption metrics on all USB ports (voltage, current, and power ) -With detection of an empty/full "power wall" battery pack connected to one of the 3 USB-A ports

When this project is finished end ended, any person with a screwdriver is able to order online and install it by one's self, easily, without requiring any additional electronics or electricity knowledge, to connect it to a 220V AC outlet with the purpose of doing later night power charging and storage, and this way, take advantage of the lower cost of electricity during those hours.

Installation in a Kitchen Wall

The previous iteration of the smart distributed power management has been working flawlessly since then... For January 2024 the new test setup for a distributed DC power management device for a low-powered electricity network using "power delivery" technologies is the one shown in the photo above. It has 3x USB-C input & output connectors for lithium battery 🔋 storage, for instance, the 3 power banks shown in the same photo, and it has 4x USB-C for power output with the purpose of powering and charging USB-C devices such as a smartwatch, a smartphone, a tablet, handheld vacuum cleaners, and even laptops.

Off the Grid usage (RV, Boats)

This smart distributed power management device can be installed and utilized off the grid, such as sailboats and motor homes. It can do battery charging when the AC plug is connected (this rev. max 30W) and a max 5V DC 5A solar charging to 3 USB-A ports. This means one can use those commercially available 100,000mA power banks as power walls. Or a real 5V DC power wall. Any will do as long as it runs on 5V DC and is able to connect to a USB-A Port.

Next Iteration

This next iteration moved to a new enclosure,the LK-WM28 sold on AliExpress here. The hardware electronics gained new specifications and functionalities. Now it has a 1.46" TFT LCD display, it features extreme low power consumption of only ~320nA, and the microcontroller is now the ESP32 C3.

This new PCB layout has new hardware components and specifications:

- Powered by the ESP32 C3 microcontroller with a maximum clock speed of 160MHz

• 2.4 GHz connectivity

- USB-C connection

• for firmware updates/upgrade
• for local troubleshooting of errors on the smart device

- Status LED

- 1.47" TFT LCD Screen to display power consumption and Solar Power Harvesting

- Extreme low power consumption. Only ~320 nano Ampere when in deep sleep.

• 3 USB-C with power delivery and fast charging up to 30W
• With 220V AC to DC converter and Power charging scheduler to allow charging only when the electricity price is lower (during the night) using machine learning algorithms
• With a 5.0V DC two-wire connector to allow DC charging from another source (for instance from solar panels)
• With a 5.0V DC two-wire connector to power an indoor main DC line for all 5.0V devices and electronics (smartphones, tablets, or any other) -With individual power consumption metrics on all USB ports (voltage, current, and power ) -With detection of an empty/full "power wall" battery pack connected to one of the 3 USB-C ports

🟡 I'm still working on this project. More testing and minor PCB corrections and improvements.

In the 7th iteration, I'll be conceptualizing, designing, and fabricating a small power wall lithium battery that will serve as a power buffer between the solar energy harvesting and the main "power delivery" DC line.

Stay tuned!

About the sponsor Seeed Studio Fusion partially sponsored this project with their PCBA Service, Offering comprehensive PCB manufacturing, prototype PCB assembly, and more. Their services cover everything from PCB fabrication, parts sourcing, and assembly, to testing. Seeed Co-create Program can assist you in bringing your product to market with expert guidance and business networking.

About the author

Miguel, an experienced professional in scientific research and smart technology solutions, adeptly combines hardware and software expertise. He has a 5-year bachelor's in civil engineering. A 2yr master in smart carbon fiber composites. A second master in machine learning and artificial intelligence. More than 30 years of experience in computer science and programming. More than 5 years in hardware electronics design (see noteworthy accomplishments here). This project is part of Miguel's effort, and work, to promote "Do It Yourself" projects, open innovation, and startup entrepreneurship using open methods for reverse-engineer, design, and prototype open software solutions, and open hardware electronics solutions.

The PCB Design Files provided on GitHub for anyone to use, are free with a Creative Commons share-alike non-commercial license. If you like this Smart Device or use it, please consider sponsoring Miguel's work Github, buy me a cup of coffee, a slice of pizza, or a book to help me study, eat, and think to work on new PCB design files.

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