Low Voltage Board Assembly

About

The purpose of this board is to act as the VCU and low volltage system of our mock EV. I put this module together after receiving a circuit schematic from Kasutara, the company helping to design this course.

48V from our HVPDU comes in through the screw terminals in the top right corner and goes directly to a DC/DC converter. This converter drops the voltage down to 12V and is distributed amongst the orange and blue distribution unit on the right. The DC/DC converter below this unit drops the voltage down even further to charge a 9V battery. This voltage is also applied to the Arduino through a diode and to a larger Distribution unit at the top of the module. The Arduino, acting as the vehicle's VCU, is connected to communication ports, the low voltage connector, a speaker, a clicking relay, and an input signal from the speed sensor.

The battery module starts disconnected through a normally open SSR. When the key on the LV board is turned, power from the 9V rechargeable battery goes through a diode to power the Arduino. This Arduino sends a signal out through the low voltage connector to the SSR, turning the high voltage power on. This then takes over control of the diode and provides power to the Arduino, which can perform any function expected of a VCU.

The communication ports are necessary for the VCU to communicate with the battery's BMS and the charging board's microcontroller.