Pre-Charge [MSXV]

Link to Previous Proposed Changes for Pre-Charge:

Link:

Changes for MCI Rev 2.0

New Suggestions

Motor controller capacitors are currently charged with a constant voltage source and series resistor. This is always 50% efficient. For a challenger vehicle, it might be better to have a switching circuit (buck topology) to charge with constant current (which would also be faster).
Keep to 12V by removing DC DC inversion
Add hall effect sensor
Make simpler by removing irrelevant portions (e.g. fan control and thermistor may have been exclusive to MOV since shorts less of an issue?)

Research Summary

Simplify Charge Pump and Depletion Mode FET (U4)
- Original parts
  - Charge pump switch regulator
    - https://www.digikey.ca/en/products/detail/microchip-technology/tc7662beoa713/418710
  - Depletion mode FET
    - https://www.digikey.ca/en/products/detail/ixys/ixth6n50d2/2183273
- New Change
  - Find closed switch to replace the two components
  - Part requirement
    - Normally closed relay
      - Form B (Form C can work)
      - Understanding Form A, Form B, Form C Contact Configuration
    - Support
      - 151.5V + safety factor (x1.5) [227.27V]
      - 0.5A
      - Ratings at 60C
    - Controllable
      - Can close on-demand or
      - Closes when car close
- Part Search
  - Implementation routes
    - For lower current parts
      - Add a series resistor to discharge path for lower current
      - Drawback
        Slower to discharge (0.25s)
        For lower voltage parts
    - Use relay in parallel
      - Less preferrable
      - Drawback
        Expensive
        May not share load equally (reduce one relay lifespan quicker)
  - Types of relay
    - http://www.electricalterminology.com/types-of-relays/
    - Classification Of Relays | Types Of Relays
  - Solid-state relay
    - https://www.digikey.ca/en/products/detail/panasonic-electric-works/AQZ404/646386
      - AQZ404
      - 400V and 0.5A (0.3A at 60C)
      - Datasheet below
      - Panasonic AQZ404 (mouser link)
      - Need lower current part implementation
      - Form B (Normally closed)
    - https://www.digikey.ca/en/products/detail/panasonic-electric-works/AQZ104/646370
      - AQZ104
      - 400V and 0.6A (~0.4A at 60C)
      - Panasonic AQZ104 (Need to wait till August for parts to ship)
      - Form A (Normally opened)
    - https://www.digikey.ca/en/products/detail/panasonic-electric-works/AQZ206G2/9597209
      - AQZ206G2
      - 600V and 1A (~0.6A at 60C)
      - Datasheet below
      - Panasonic AQZ206G2 (Need to wait till September for parts to ship)
      - Form A (Normally opened)
- Implementation plans
  - Existing parts
    - Remove
      - Charge pump and corresponding capacitors (C11, C12, C13, U4)
      - Series Resistor (R19)
    - Depends on parts
      - Pull-down resistor (R21)
      - Zener diode (D8)
    - Keep
      - LED and resistor (LED5 + R43)
  - Schematic
    - Q1 and Q2, replace with single relay
      - Panasonic AQZ104
        Cheaper ($12-16)
        In stock
        Current rating may not be enough at 60C
      - Panasonic AQZ206G2
        More Expensive ($30)
        Have to wait
        Enough current rating
      - Note: May not implement if not enough space
    - Q3, use relay (AQZ404) with series resistor
      - Panasonic AQZ404
      - Needs to be done
        If approved, should buy early
- Pre-charge timing
  - Using 270 uF Cap MC
  - 300 ohm
  - 500 ohm
Out of stock IC
- IC Load Switch
  - OOS
    - NCP45521IMNTWG-H
      - https://www.digikey.ca/en/products/detail/onsemi/NCP45521IMNTWG-H/5257785?s=N4IgTCBcDaIHIGEAKAWArGsBGAkgWTgBUB1AcQFoAJEAXQF8g
      - onsemi NCP45521IMNTWG-H
  - Alternative
    - NCP45770IMN24TWG
      - https://www.digikey.ca/en/products/detail/onsemi/ncp45770imn24twg/12180092
- CAN Controller
  - OOS
    - MCP2515T-I/ST
      - https://www.digikey.ca/en/products/detail/microchip-technology/MCP2515T-I-ST/593682?s=N4IgTCBcDaILIGEAKYCsBGVAVAtASQHoBlLEAXQF8g
      - https://www.mouser.ca/ProductDetail/Microchip-Technology/MCP2515T-I-ST?qs=uMUszenkLLIwkGYxhCCgRQ%3D%3D
  - Alternative
    - MCP2515-E/P
      - https://www.mouser.ca/ProductDetail/Microchip-Technology/MCP2515-I-P?qs=hklUZQQMghMXVOd4j8inGA%3D%3D
      - Note: Through-hole
- CAN Reciever
  - OOS
    - TCAN332DR
      - https://www.digikey.ca/en/products/detail/texas-instruments/TCAN332DR/5823563?s=N4IgTCBcDa4JwDYC0AWAzAdgIxabgcgCIgC6AvkA
      - https://www.mouser.ca/ProductDetail/Texas-Instruments/TCAN332DR?qs=n%252BTO0c4TDSYIUeM9WmVMtA%3D%3D
  - Alternative
    - MCP2551T-I/SN
      - https://www.digikey.ca/en/products/detail/microchip-technology/MCP2551T-I-SN/509535
- Optoisolator
  - OOS
    - HCPL-0211-000E
      - https://www.mouser.ca/ProductDetail/Broadcom-Avago/HCPL-0211-000E?qs=xnajaXqBF9%252BJAicV1wntGA%3D%3D
  - Alternative
    - HCPL-0211-500E
      - https://www.mouser.ca/ProductDetail/Broadcom-Avago/HCPL-0211-500E?qs=xnajaXqBF9%2FtZ67k7S1qGw%3D%3D
Smaller changes (Check with)
- Removing:
  - Fan control
    - Remove fan connector
    - Remove entire fan control sheet
  - Thermistor
    - Remove thermistor connector
    - Remove entire thermistor sheet
- Add jumpers near AND gate to skip it

Part List

AQZ404 (Solid State Relay)
- Replaces Q3
  - Needs to be with series resistor
- Panasonic AQZ404

IC Load Switch
- NCP45770IMN24TWG
  - https://www.digikey.ca/en/products/detail/onsemi/ncp45770imn24twg/12180092
  - https://www.mouser.ca/ProductDetail/onsemi/NCP45770IMN24TWG?qs=7MVldsJ5UayF2EDms7TgPA%3D%3D
CAN Controller
- MCP2515T-I/SO
  - https://www.mouser.ca/ProductDetail/Microchip-Technology-Atmel/MCP2515-I-SO?qs=KwArPi4cUogGDbGnphOvtQ%3D%3D
    - Present in the bay but OOS
CAN Reciever
- MCP2551T-I/SN
  - https://www.digikey.ca/en/products/detail/microchip-technology/MCP2551T-I-SN/509535
Optoisolator
- HCPL-0211-500E
  - https://www.mouser.ca/ProductDetail/Broadcom-Avago/HCPL-0211-500E?qs=xnajaXqBF9%2FtZ67k7S1qGw%3D%3D
  - Same as HCPL-0211-000E