TU Delft Hyperloop’s Custom Safety System & Mixed-Signal Board

Author: TU Delft Hyperloop / Published on: 11 August 2026

Introduction

Delft Hyperloop commits itself every year to the completion of a full product cycle, a massive undertaking that requires intense motivation, precise planning, and manufacturing services we can implicitly rely on. Reliability is the key word here, as Delft Hyperloop X aims to present its prototype, Theia II, as the most reliable full-scale hyperloop vehicle yet, optimized for long endurance runs. On top of that, Theia II will be the first prototype able to carry up to 500kg of cargo with it. In this way, Delft Hyperloop breaks the barrier between prototype and future applications by demonstrating that the objective of this team in full-scale prototyping no longer relies on sole functionality of the system.

Eurocircuits is a leading PCBA company that Delft Hyperloop is very familiar with. This year we again had the pleasure to enjoy a partnership with them. Assisting us with the design and production of our inhouse-built Battery Management System, safety systems, and a state-of-the-art mixed signal board. Their services are one of the pillars on which Delft Hyperloop builds the future of transportation.

The Challenge: Time and Expertise

Delft Hyperloop is a multidisciplinary engineering team that dedicates an entire year to bringing a prototype from design to reality. Over 40 students pour their passion into this project, but while motivation is plentiful, time is our most critical constraint.

The Sense and Control Department is tasked with building the central nervous system of the prototype. They develop all the vehicle’s electronics, from sensor data extraction to the communication highways connecting our subsystems. While software programming dictates the pod’s functionality, custom hardware is what truly brings it to life.

However, designing, testing, and producing complex Printed Circuit Board Assemblies (PCBAs) in-house consumes a massive amount of time. This bottleneck directly threatened our timeline, meaning we would have to compromise on other critical engineering milestones to get the boards built. To stay on schedule without sacrificing our rigorous safety standards, we needed a highly capable manufacturing partner. We required a solution that could deliver reliable, custom mixed-signal boards quickly, allowing our engineers to focus entirely on system integration and testing rather than getting bogged down in production logistics.

The Solution: Why We Chose Eurocircuits

Given our strict requirements for speed, precision, and reliability, Eurocircuits was the clear choice. Because we had partnered with them in the past, we knew their manufacturing standards could meet the rigorous demands of our new prototype, Theia II.

Instead of juggling separate board manufacturers and component suppliers, we seamlessly integrated Eurocircuits’ comprehensive PCBA services directly into our workflow. We handed off the complex schematics for our in-house Battery Management System (BMS) and safety systems, trusting them to deliver fully assembled, ready-to-test hardware. This allowed our Sense and Control team to immediately plug the hardware into our software environment the moment the boards arrived.

Here are the key features of their service that made the difference:

Online PCB Visualizer & DFM Tools: Before a single board was printed, Eurocircuits’ intuitive online Design for Manufacturing (DFM) checker allowed us to visualize our designs and catch potential layout errors. This preventative step saved us from costly, time-consuming design revisions.
Turnkey PCBA (Assembly) Services: Sourcing individual components and soldering complex, high-density boards in a student lab is a massive time sink. Eurocircuits handled the complete assembly process, delivering fully populated boards that slashed our hardware lead times from weeks to mere days.
Precision Mixed-Signal Fabrication: Our mixed-signal board required flawless isolation between sensitive analog sensor readings and high-power digital logic. Eurocircuits’ strict European manufacturing tolerances ensured superior signal integrity, which is critical for the safety and reliability of a highly dynamic vehicle like Theia II.

The Impact: Journey to an early stable system

This year, the Sense and Control department has an especially unique composition; all engineers are working on a part-time basis. Where, normally, compromising on the available time would be a part of the team’s part-time reality, Eurocircuits’ seamless PCB and PCBA services proved as an immense productivity boost for hardware development. It allowed Delft Hyperloop to focus fully on the design and testing phase of the prototype. Because of this, engineers have been able to take on complex hardware challenges that rival the output of full-time engineers.

Deep Dive: The Custom Hardware Behind Theia II

To give you a closer look at the complexity Eurocircuits helped us navigate, here is a breakdown of the four critical, custom-built hardware systems powering our newest prototype.

1. Battery Management System (BMS)

The Powertrain department developed a custom high-voltage battery system comprising 10 individual 60V packs. Operating at a total of 600V, this massive power source requires rigorous, real-time monitoring to ensure the absolute safety of the hyperloop vehicle. To achieve this level of precision control, Delft Hyperloop designed an entirely in-house BMS.

The system utilizes a centralized controller-worker architecture:

Worker Units: Every individual battery pack is equipped with its own worker unit that continuously monitors cell voltages and temperatures.
Central Controller: All 10 worker units are daisy-chained via an isoSPI (isolated Serial Peripheral Interface) connection to pass multiplexed measurements to the main controller.

By keeping the worker units strictly dedicated to telemetry, control remains entirely centralized and explicit. Beyond managing the worker network, the central controller processes data from an integrated Isolation Monitoring Device (IMD), monitors a high-precision current sensor, and commands the high-voltage safety contactors.

2. Mixed-Signal Acquisition Board

Theia II achieves stable levitation through a complex array of sensors. To ensure system reliability when passing over thermal gaps, where positional offset data can momentarily become invalid, we utilize an Inertial Measurement Unit (IMU) to execute advanced sensor fusion over the vehicle’s spatial data.

However, sensor fusion is only effective if the IMU can be read out at high speed and with high accuracy, and if that data reaches our real-time dynamic model without latency. To bridge this gap, we designed a custom mixed-signal acquisition board.

The board runs on a 24V supply rail that is progressively stepped down to the operating voltages required by each component. Signal flow proceeds left to right: accelerometer and gyroscope signals from the external IMU are first pre-amplified, then fed into an ADC for digitization. The digitized data is transferred via SPI to an STM32 microcontroller, which uses its internal MAC to communicate with an external PHY over RMII. The PHY then converts the Ethernet protocol into electrical signals suitable for transmission over an Ethernet cable.

Several components on this board require small SMD packages with tight tolerances (down to 0.1%), and a solid ground plane was essential for reliable return paths across the high-speed and analog sections. Eurocircuits’ precision assembly capabilities and high-quality board manufacturing made designing and producing this board significantly easier.

3. Analog Braking PCB

While the majority of the prototype’s functionality relies on a tight interplay between software and hardware, certain mission-critical safety applications demand absolute immunity to software glitches, loop jitter, or operating system crashes.

To eliminate software-related risks entirely, Delft Hyperloop iterates every year on a dedicated Analog Braking PCB. This pure-hardware safety system bypasses the main microcontrollers entirely, performing the most critical function of the prototype, deploying the brakes instantly and reliably whenever a fault condition occurs, in a completely fail-safe manner.

4. High-Voltage Active Light

The High-Voltage Active Light is one of the simpler boards we have manufactured at Eurocircuits. It consists of a board that detects a voltage threshold and powers certain outputs depending on it e.g. visual cues representing the state of the vehicle. In our system, it is used to detect the ‘High-Voltage Active’ state of our system in a completely analog manner, ensuring that access to the prototype is only granted when the bus voltage is below 60V DC, no matter the functionality level of the prototype.

5. Engineer Experience

Beyond the technical specs, we were most satisfied with how smooth the overall experience was working with Eurocircuits. The ordering process was straightforward, the design analysis checks caught potential errors early rather than after production, and the turnaround time allowed us to iterate quickly between design revisions and testing. For our student team, having a reliable manufacturing partner without worrying about delays or fabrication issues was a major advantage. The quality of the boards also exceeded our expectations, and it gave us more time to spend on engineering challenges and less time worrying weather if a board would come back fit for its designed purpose.

Looking Ahead

While the journey of Delft Hyperloop X comes to an end, a new team is ready to take over our aspirations and ambitions. Eurocircuits has shown us how accessible professional PCB and PCBA services can be, especially when we have limited time on our hands. Eurocircuits has enabled us to design custom solutions with seamless integration of production and logistics.