Low Voltage

Division Overview 

The low-voltage division oversees all the electrical components that operate below 60V. The division designs and integrates the car’s control system and safety features. Their main components are the driver controls, the shutdown circuit, the wiring harness, and the data logging with their sensors. This division ensures safety and seamless communication between all the other subsystems.    

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Components 

1. ECU (Electronic Control Unit) 

• Acts as the car’s central controller, processing inputs from sensors and driver commands. 

• Runs embedded code (often C/Arduino-based) to control actuators and safety functions. 

• Interfaces with shutdown circuits, traction control, and data acquisition systems. 

2. Wiring Harness  

• Distributes low-voltage power and communication signals to all electronic devices.

• Designed with proper wire gauge selection  to handle current safely and minimize voltage drop. 

• Requires correct grounding and insulation to reduce electrical noise and prevent failures. 

3. Sensors

• Provide real-time data such as wheel speed, acceleration, temperature, pressure, and cooling system performance. 

• Used for performance analysis (traction, tire behavior) and safety monitoring (overheating, pump failures). 

• Signals can be analog (continuous values) or digital (on/off states), requiring different processing.  

4. BMS (Battery Management System)

• Monitors and protects the HV accumulator but communicates via LV signals. 

• Provides information on cell voltages, temperatures, and balancing operations. 

• Ensures safe charging/discharging by sending warnings or triggering shutdowns if faults occur. 

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Requirements 

• INGE 3016: Algorithms and Programming 

• INEL 3105: Circuits I 

• INEL 4201: Electronics I 

• Programming skills (C++, Python) 

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Division Knowledge Guide 

Every Low-voltage member must be skilled in diagnosing electronic issues. If a component works only partially, common causes include poor grounding, damaged connectors, or incorrect wiring. Frequent fuse failures usually point to overcurrent, undersized wire gauge, or short circuits. Correct wire gauge is determined based on expected current draw, wire length, and safety margin. Resistance can be reduced by shortening wire runs, increasing conductor thickness, and ensuring high-quality crimps. 

Understanding digital vs. analog signals is fundamental. Analog signals (temperature, pressure) vary continuously, while digital signals (switches, wheel speed pulses) switch between discrete states. This distinction affects how the ECU processes information. Sensors integrated into LV also validate system health: traction sensors reveal grip conditions, and cooling system sensors ensure fans and pumps are functioning correctly. 

Troubleshooting is a core LV skill. For example, if the fuel pump fuse blows immediately, the process includes checking for shorts, testing pump current draw, and verifying grounding. If a cooling fan connector melts, it usually indicates incorrect wire gauge or poor connector choice, not external heat. 

Although LV runs at safe voltages, it directly supports high-voltage systems through the BMS, shutdown circuits, and data logging. This makes LV essential for both safety and performance monitoring. 

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