FS Team Tallinn in 2023

FS Team Tallinn

FS Team Tallinn has built electric formula cars since 2013. We built our 11^th competitor FEST23 this year, which for the first time could drive with and without a driver. We took part of 5 competitions in Italy, Austria, Hungary, Germany, and Croatia, where we achieved many podium places in different disciplines.

© FSG, Kohler

In total, we have more than 20 self-developed PCBs in our car. Eurocircuits’ high quality and quick manufacturing times were essential to finishing all the projects on time and increasing the overall reliability of our electronics system. Whenever a quick prototype or a new revision was needed. Eurocircuits’ quick manufacturing times enabled us to go from design to a finished product within 1-2 weeks.

DCDC converters

We use a DCDC converter to supply our low voltage system from the 600V accumulator. A commercial DCDC converter is used to convert 600V to a lower voltage, but its output is dependent on the accumulator voltage. To get stable 24V output, 2 DCDC converters were designed.  Splitting the DCDC converters allowed for higher efficiency and better EMC.

A smaller 168W DCDC converter is located inside our accumulator, to supply the general low voltage system. The DCDC is passively cooled and has an efficiency of ~97%. Two different versions of the converter were designed, manufactured, and tested. One uses standard Si MOSFETs. The other uses GaN MOSFETs, which enables to have higher efficiency thanks to lower switching losses of the MOSFETs.

A second larger DCDC converter is used for the cooling and driverless systems. To increase the power density of the DCDC converter, it was split into 2 PCBs, which are stacked on top of each other. It has an output power of 504W with an efficiency of 98%. High efficiency was achieved thanks to the use of external gate drivers in combination with a buck controller. The DCDC converter has active cooling control and temperature measurements for overtemperature protection.

EBS PCB

This year we integrated the driverless system into our newest car FEST23. Because of that additional electronics were needed, one of which is EBS(emergency brake system) control unit. It’s a critical PCB that ensures the safety of the car and functionality of the driverless system. It’s responsible for checking the car’s state, actuating the emergency brakes and autonomous state indicators. It also has multiple analog and digital inputs, to get sensor inputs and measure different voltages.