Embedded Files
Charge Controller
Charge Controller
Description
Description
The charge controller is a tool design to be used in ensuring that the battery and charger are safe for charging. The board is used to monitor the battery charging while it is off of the bike. The user has the battery and charger connected by amp seals in which the charger communicates through CAN and displays to the user information that allows them to select the current and voltage that goes to the charger and the safety of the connections. This is mostly to be used in terms of running diagnostics checks for when the team prepares to race and improve the speed of these tests for the future. The board uses an LCD to display information and uses a quadrature encoder to allow the user to navigate a menu and specify the voltage and current at which the charger charges the battery at.
Charge Controller V1.0
Charge Controller V1.0
See slides for initial problem definition and schematics for CC V1.0
The first revision had the team members work to design from scratch a board that would switch the on/off status of a contactor from a battery to charger. This would allow for safety of the bike battery to charger in which we could save time in testing the bikes status. A relay is used to break the connection between the charger and the battery. The user just monitors and determines when to start and stop testing with standby for any possible issues.
Charge Controller V2.0
Charge Controller V2.0
The second revision removes the relay, buck converters and screw terminals and incorporates an extra amp seal, push buttons, and a quadrature encoder. The user menu on the screen will be selectable with the encoder and the confirmation is done with the button incorporated to the encoder. In V2.1, the routing of the board has been redone to improve neatness and usability.
Charge Controller Revision
Charge Controller Revision
Left: Charge Controller V1.0
Right: Charge Controller V2.1
In V2.0, the functionality of the board has changed from connecting the charger output to the battery and switching it via a relay, to connecting to the BMS and the charger via CAN and allowing for users to tell the charge controller what current and voltage to send to the battery. The connection to the BMS allows the board to monitor the state of charge and pack status. Other than the headers, the buck converters, and amp seals, the mechanical team will have to consider the height of the encoder with the enclosure that will be made.
Revision History
Revision History
Revision 2.1:
Routing and component placement greatly improved for neatness and usability by other teams
Potentiometers replaced with single quadrature encoder to be used to navigate a menu and set charging current/voltage
Revision 2.0:
Relay were removed as they became redundant
Removed screw terminals for the connection between charger output and BMS
Potentiometers used to set voltage and current of charging
Replaced TI buck converters with simpler RECOM buck converters
New connections: one amp seal to BMS, one amp seal to charger CAN
Revision 1.0:
Starting from scratch and designing a board that allows for the safety of the charger and battery when there is an issue.
Issues
Issues
Revision V1.0:
had issues with the power supply and the connections made in the LCD and the relay footprint, plus as it was latched.
The circuitry of the power supplies was also incorrect and needed to be modified, replaced the step-down circuitry for two buck converters for 12V to 3.3V and 12V to 5V.
Amp seal footprint was not correctly aligned which required some drilling to be done to connect it to the board.
I2C pullups were incorrectly specced with 100Ohm instead of 10kOhms
Current Revision V2.1
Quadrature encoder (see below) S1 port should be connected to 3V3. A work-around is to connect S2 to 3V3 by depopulating C50, rotating R39, so it occupies the two pads circled below in the center image, and jumping 3V3 to the pad as shown in the right image.
Noisy encoder outputs: fixed by placing 0.1uF caps in parallel with RencA and RencB
Project Team Members
Project Team Members
John Da Silva - Electrical member
Jason Wong - Electrical member
Christian Secular - Electrical member
Katie Trostle - Industrial member
Matthew Heller - Firmware member
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