Formula Racing Miskolc
PCB Documentation
Main PCB and MCU Expansion Board
For a Formula Student race car, it is important to use a reliable and robust electrical system. In our car, we figured out a solution, which is a main board, designed for power distribution and carrying some of the signals for our data-logger.
Our main PCB is our most complex design, compared to our other electrical circuits. It is a 2-layer board with unique shape, which is mounted inside our electrical box and the main interface is a 60-pin sealed connector.
This allows us to connect our electrical system and ECU together with reliable connection. We also use electro-mechanical clutch actuation and for this, we use a micro-controller attached to our main board.
The main PCB contains relays for switching our peripherals such as fuel pump, cooling fans and ignition. It has also connectors for our data-logging device, and DC-DC converters for our servomotors on-board.
We also designed fuses onto the PCB, so we do not need a fuse box anymore, which is a great solution and makes our electrical system more practical.
The unique shape of our PCB was needed to fit that inside our electrical box practically so we could save a lot of space inside. This meant that our electrical and mechanical designers had to work together during the design of the PCB and the electrical box and constantly communicate about the actual sizes and orientations.
Thanks to good cooperation, we were able to create a well-designed PCB and electrical box, which are perfectly fits to our needs according to their placement and measures.
First, we used the Naked Proto option, to receive a PCB for initial tests with new features, after testing the circuit, we performed additional improvement on the design and we ordered the PCBs from the PCB proto service.
The MCU expansion board is a simple PCB, which connects our controller MCU to the main board and it perfectly fits to our telemetry connectors.
With this feature we can change the features from our myRIO unit to the MCU.
The MCU also controls the DRS system. With the expansion board we do not need to change anything in the cable harness when we are testing different control method with different control units.
 MCU Expansion Board |  Main PCB |
BSPD
According to the 2019 rule book, every team must use a device, which breaks the kill-switch circuit during a specified state of the brake-system and the throttle-position.
We decided to use the solution, offered on the official FSG rules website.
After some modification on the PCB, we could send it for production and design a custom-made case for the circuit.
The theory of the BSPD is to prevent damage of the electric motors during hard braking when the pilot also pushes the accelerator pedal, but this feature now is applied also in the combustion vehicles.
The concept of the circuit is simple, it is based on comparator’s and RC pairs for setting the time delays. For the 2020 season, our team will develop its own design for the BSPD.
USB interface PCB
For programming and debugging the features controlled by the MCU, we decided to place an USB connector on our car’s right-side control plate. For this, we received a PCB mountable THT USB connector.
To rigidly fix the wires to the connector we designed a PCB, which connects the USB connector to the wires from the wire-harness. This solution turned out to be very stable, making the debugging procedure easy even during tests, on the racetracks.
Gearshift PCB
Our gearshift PCB is showing the actual gearbox position during a dyno run.
We have a separate setup for the testing and tuning only our engines and this PCB allows the test team to know the exact gear position during a test where the dashboard unit used in our car is attached elsewhere and shows another, useful information about the engine state.
This PCB is also useful for new members to learn micro-controller programming.
Thanks to Eurocircuits
Thanks to Eurocircuits support, we received the best quality PCBs, as usual and they served without any problem during our 2019 season.
For more information please visit the Formula Racing Miskolc website.
