Imported from GitHub: henrysg1/solar-car-dcdc · commit d6bebeb · license MIT

Description

This repository contains the KiCAD project for the University of Nottingham's solar race car DCDC converter.

README

DC-DC Converter for Solar Car

Overview

This repository contains the design files for a DC-DC converter used in the University of Nottingham's solar race car. The converter steps down the battery voltage from 135V to 12V, which is essential for powering various low-voltage components in the vehicle.

Features

• Input Voltage: 135V
• Output Voltage: 12V
• Output Current: Up to 50A
• Efficiency: > 90%
• Protection: Overvoltage, Overcurrent, Thermal Shutdown
• Compact PCB Design

Status

The PCB revision in this repository has been manufactured and succesfully tested and implemented in the solar car, verifying that the system works as intended.

Getting Started

Prerequisites

To work with the design files, you will need:

• KiCad for schematic and PCB design. Important Note: For this project, a Nightly Development Build of KiCAD has been used (6.99). The project will not work on a Stable Version release (6.00)

Usage

1. Clone the repository:

   git clone https://github.com/yourusername/dcdc-converter-solar-car.git
   cd dcdc-converter-solar-car
   

2. Include the component files in the KiCAD project (in the 'Component Files' folder)
3. Open the schematic file (dcdc_converter.sch) in KiCad.
4. Open the PCB layout file (dcdc_converter.kicad_pcb) in KiCad.

Schematic

The schematic for the DC-DC converter is designed to step down the voltage from 135V to 12V. Here are the key sections and components:

Input Section

• J2, J3 (Connectors): These connectors receive the high voltage (135V) input.
• F1, F2 (5A Fuses): Provide overcurrent protection for the high voltage input.

Relay Control

• K1 (Relay): This relay enables or disables the DC-DC converter based on an external switch connected through IPL1.
• D1 (Diode): Acts as a flyback diode for the relay coil, protecting against voltage spikes.

Primary Conversion Stage

• L1, L2 (1µH Inductors): Form LC filters along with C1 and C2 to smooth the input voltage.
• R1, R2 (1Ω Resistors): Used for current sensing in the primary stage.

DC-DC Converter Modules

• PS1, PS2 (DCM3623T5N13B4T00): These modules handle the main conversion from high to low voltage. They include control and feedback components:
  • R5, R6 (510Ω, 50kΩ Resistors)
  • RV1, RV2 (250kΩ Potentiometers)
  • D3, D4 (LTST-C193KRKT-5A Diodes)

Output Section

• L3, L4 (0.15µH Inductors): Further filter the output voltage.
• C3, C4 (1000µF Capacitors): Stabilize the output voltage.
• F4, F5 (25A Fuses): Provide overcurrent protection for the output.
• J4 (Output Connector): The connector for accessing the stepped-down 12V output.

This design ensures efficient voltage conversion with necessary protections for both input and output stages.

PCB Layout

The PCB layout is designed to maximise efficiency and handle high current traces. Key considerations include:

• Trace Widths: Sized appropriately for current handling.
• Component Placement: Optimised for thermal management and isolating voltages.
• Ground Plane: Ensures low impedance return paths.

License

This project is licensed under the MIT License. See the LICENSE file for details.

Acknowledgments

University of Nottingham Solar Race Team
KiCad Community