Overview
We'd like to minimize the number of different connectors and components that exist in the car. It's terrible for inventory management and means we have a lot of board-specific parts and crimping.
Connectors
All of our connectors must be positive-locking and able to withstand high-vibration environments, ideally shrouded. Anything outside of an enclosure should be sealed and locking with strain relief.
So far, we have identified the following use cases for connectors in MSXII:
| Type | Scenario | Expected Voltage | Expected Current | Number of Circuits |
|---|---|---|---|---|
| Wire-to-board | Connecting signal wires between boards or panel mounts within an enclosure (ex. CAN, BMS) | 3.3v | <1A | 2~16+ |
| Wire-to-board | Supplying power to boards or relays | 12v | <1A (3.2A peak) | 2 |
| Wire-to-board | Supplying power from Chaos to other systems | 12v | 2A (6A bursts if for horn) | 2 |
| Wire-to-board | Supplying power from the DC-DC or aux battery to Chaos | 12v | 10A? | 2 |
| Wire-to-board | HV measurement for precharge | 150v | <1A | 2 |
| Panel-to-panel | CAN, power, and auxiliary signal (ex. killswitch or MPPT enable) between enclosures | 12v | 2A (6A bursts if for horn) | 6+ |
| Panel-to-panel | HV power | 150v | 150A | 2 |
Currently, we have identified the following connectors as possible candidates:
| Connector | Purpose | Max. Rated Voltage | Max. Rated Current | Max. Mating Cycles |
|---|---|---|---|---|
| Molex CLIK-Mate | Wire-to-board: 1.25mm for signal and 1.50mm for power | 1.25mm: 50V 1.50mm: 100V | 1.25mm: 1A 1.50mm: 2A (3A with 2 circuits) | 30 |
| Anderson SB120 | HV power - note that this does not follow any of the rules | high | 240A | 10k |
| Hirose DF3 | Alternative to Clik-Mate (2mm pitch 2 circuit variant available) Not locking? | 250V AC? | 3A | 30 tin, 50 gold |
| M12-5 (DeviceNet) | CAN and power | 300V? | 4A (power) | |
| TE Deutsch | CAN, power, aux signal | |||
| Molex DuraClik | Wire-to-board (2mm) | 125V | 3A | 30 |
| Molex UltraFit (Gold Plated) | Wire-to-board: LV Power Connector | 400V | 12A | 200 |
After testing, the CLIK-Mates 1.5mm will be a good choice for any signal wire-to-board connections required as long as we're satisfied with its lifespan. The 1.25mm versions extremely difficult to crimp and have a maximum wire size of 26 awg. The DuraCliks are a good alternative as they are designed explicitly for automotive use and support ISLs or TPAs for terminal retention and positioning.
We plan on powering all boards through the carrier board, so we want to find a high-current (10A) 2-pin connector for all LV power usage.
Follow-up
We have standardized on DuraClik ISLs for signal wires and Ultrafit TPAs for power. In addition, most of our components should be 0603.
We've also decided on Molex MX150Ls for panel-to-panel connectors as they seem to be the only connector family with options for panel-mount connectors in the 22-18awg range.