2023-02-11 - Connector Clarifications

Owned by Daniel Puratich, created
Last updated: 2023-02-16
4 min read

Change Description

Icarus

Connector Standardizations

Daniel Puratich

Description of Change

Connector Standardization” section should be cleared and updated to the following:

  • Gender Decoding

    • Gender conventions are defined below.

    • Gender is defined by the metal conductors in all cases. Plastic housing should be ignored when deciphering gender. The manufacturer’s dictated gender decision takes preference over this, however, it will be clearly iterated here if that is the case.

  • XT series connectors are convenient, common in the hobby world, fairly reliable, and relatively cheap and will therefore be employed for all WARG DC power connections whenever possible.

    • COTS PCBAs after require solder pad connections which we will accommodate, but breakout to our prioritized connectors whenever possible.

  • XT60 connectors will be prioritized for any sub 150 A pulsed DC connection

    • For ESCs and anything smaller this should be prioritized

    • XT60-F is on batteries and so the XT60-F should be used on any voltage source and XT60-M should be used on any load. This gender convention is also used in the COTS world and keeps things simple.

      • Manufacturer PN Gender: “-F” is female & “-M” is male

    • Custom hardware will use XT60PW series connectors and follow the above gender convention.

  • XT30s will be avoided when possible for simplicity

    • While XT30s are smaller and meet our current requirements for lots of low voltage loads in order to minimize the amount of connectors we need to stock and use XT30s will not be prioritized when an XT60 can be used.

    • COTS loads and sources with XT30s will be adapted to XT60 through harnessing

  • XT90 connectors will be used for any greater than 150 A pulsed DC connections

    • COTS higher current 6S and above batteries often ship with these XT90s and so we will accommodate such a design decision as they are rated for the higher current.

    • Anti-spark XT90s should be used whenever possible to limit sparks from in-rush condition though this may not always be possible.

    • XT90 battery input splitting into ESC and converter connections should be done on a properly specified PCB with XT connections done in harnessing.

  • AC Mains is not used on any WARG aircraft and therefore a connector will not be specified

    • No voltage sources exceeding 55 V during nominal continuous operation are to be present on aircraft due to a lack of necessity and safety concerns

  • ESC BLDC Motor Controller Phase connectors will be specified in the future and require more decisions in the future.

    • 3.5mm banana connections is a solid option from the hobby world, but they can be a pain. Other size banana connections may be used as well on smaller aircraft as we come up with more specific decisions.

      • Gender Convention: Female on ESCs, Male on motors

    • Anderson Power pole series connectors are promising and have significant use in FRC, but will require validation before we fully adopt them in place of the ol' banana connectors

      • Gender is not present on these but ideally three different colors are used.

  • PWM Signal Connections

    • Should be done with with standard twisted PWM cables. Ideally locking stuff so it doesn’t pull out easily.

    • Simplest solution is often the best so sticking with these seems ideal.

    • Gender convention: Male pins on the signal generator and female sockets on the signal receivers.

    • We will use mechanical locking on the headers, copying how it is done in Vex to lock the PWM connectors into the board they connect to.

      • Where this is not viable we will defer to hot glue

  • Other low voltage signal connections

    • Debug versions should be done on standard 100mil pitch headers and jumpers

    • Flight versions should copy Pixhawk connectors whenever possible

    • Specific components will follow manufacturer recommended connectors if we for sure want to support it

      • i.e. the VectorNav VN-300 has it’s own connector we should just use since we are going to use this component on our system for sure!

    • If all the above fail we will defer to automotive and marine standards

Implementation

XT60 stuff is mostly codifying what’s already happening. The other stuff is just stating what’s been implied for a bit.

Reason for Change

Clarity, reliability, & ease of connections.

Priority

High - Just to keep things standard.

Impact of Not Responding to Change

Confusion, annoying extra harnessing, and cost of random connectors

What Groups, People, Sub-teams Need to be Notified?

  • Electrical

  • Mechanical

  • Sysint

  • EFS

Change Impact

Additional Parts/Resources Required and Costs

We may need to buy some more XT60s, but in the long run this will save us money on making random harnesses.

Impact on deadlines

Implementation will be effectively instant.

Alternatives and Recommendations

Alternatives are suffering. Recommendations are approving this RFC lol.

Comments

None.

Change Request Sign Off <System Integration>

Status

Merged, Approved by Anni and Dhruv

Accepted / On Hold / Rejected / More info Requested

Comments

Signatures/Name