In this article, we will guide you through a beginner-friendly project to design a solar power regulator PCB. This solar charger is crucial for optimizing the power output of your solar panels, ensuring they charge efficiently to their maximum intended capacity.

Required Components for the Project

Background Information

In modern solar energy systems, Maximum Power Point Tracking (MPPT) technology is used to optimize the charging of solar panels. MPPT continuously adjusts the solar panel’s operating point to extract the maximum power based on sunlight conditions. However, this method can be less effective in low-light conditions, such as during cloudy or rainy days. This is where a dedicated solar charger, like the one described here, becomes essential. The LT3652 is a highly efficient DC-to-DC converter that helps maximize charging efficiency, ensuring your solar system remains reliable even under less-than-ideal conditions.

How the LT3652 Works

Compared to other regulators, the LT3652 is highly efficient and supports DC-to-DC power conversion.

• The LT3652 receives DC power from the solar panels, converts it into high-frequency AC, and then reconverts it into the appropriate DC voltage and current required by the battery being charged.
• It uses input regulation to ensure that the solar panel operates at its peak power output, optimizing energy conversion.
• The converter can be configured to stop charging automatically when the current drops below 1/10 of the programmed value, protecting both the battery and the panel.

Schematic Diagram

The schematic below shows the LT3652 integrated into the design. This component is key to converting and regulating the DC power to charge the solar battery effectively.

• The barrel jack functions as a switch, allowing you to disconnect the internal battery from the panel and connect an external one. This feature ensures charging continues even when the panel is not generating power.
• The schematic was designed using KiCAD EDA, a powerful and essential tool for circuit design and PCB layout.

PCB Design

After finalizing the schematic, the design is converted into a PCB layout.

• During the design phase, you can specify the dimensions of the components and the overall board size according to your project’s requirements.
• KiCAD’s design rule checks (DRC) ensure that the PCB is error-free, automatically identifying potential issues before manufacturing.
• Since the solar charge controller is crucial for charging the batteries, it’s important to double-check all connections. A missed or incorrect connection could damage expensive components, such as the solar panel or battery.
• Below is an image of the fully routed PCB, ready for layout verification.

• After completing the layout and generating the 3D view of the design, this is the final result.

Design Manufacturing

Once the design is complete, the next step is fabrication. This involves communicating with a PCB manufacturer who can produce the physical board based on your design files.

• I rely on WellCircuits for PCB manufacturing. To submit an order, visit the Ordering page on their website and inquire about the process.
• You’ll need to provide all the necessary manufacturing files from your EDA tool. This includes the Gerber files, Bill of Materials (BOM), and Pick-and-Place files.

Bill of Materials (BOM)

The BOM is a crucial document for ordering components required to assemble your PCB. It can be generated directly from your design tool.

To create the BOM file in KiCAD:

·        Go to File, select Fabrication Output, and choose BOM.

·        Click to generate the BOM file in Excel format. Once opened, you can edit it to meet the manufacturer’s specific requirements.

Gerber Files

To generate Gerber files for PCB manufacturing, follow these steps:

·        Click on the icon to open the plot window, then select “Plot” to generate the Gerber files.

·        Once completed, you will have your Gerber files ready for submission to the manufacturer.

This concludes our simple yet comprehensive guide to designing a solar power regulator PCB. If you have any questions about PCB or PCBA, feel free to contact me at info@wellcircuits.com.