Thruster PCB Breadboard

[c-bash]

An open task from last year that was not accomplished. Needs to replace the solderless breadboard on each platform with a (more permanent) PCB. Design needs to be reviewed by the admin team before any submissions for manufacturing.

[c-bash]

This is the breadboard to be replaced on each platform. See more information on this board here.

The circuit for the thruster actuation is shown in part here, which can be found under the Power Systems wiki page.

The MOSFETs should not be soldered directly to the board since sometimes these components get damaged and must be replaced. Instead, they should be connected through a female header connector (such as this, note, this specific connector has not be confirmed to be compatible with the dimensions of the MOSFET).

The MOSFETS used in the current design must be carried over to the new design---in other words, the PSMN022-30PL,127 must be used.

Most components (e.g., MOSFETS, some connectors, resistors) have been ordered by last year's capstone team. These components can be found in the WIRING drawer of the lab. I believe all these components are through-hole. If surface mount components are desired (e.g., resistors), these must be ordered.

[sean-charlton]

The current design of the PCB uses 0.4mm traces on a single side.

[sean-charlton]

Schematic of the thruster circuit

[adamvigneron]

Met with Alison Fong, a hardware technologist in the Department of Electronics.

For the next version of the PCB, Alison agrees that:

• the harness should include an explicit ground connection. She agreed that the circular connector currently used on the breadboard is a good candidate.
• a Schottky diode connected across the solenoid terminals would protect the solenoids against inductive kickback (a so-called “flyback diode”).
• an opto-coupler could be used to fully isolate the 5V Xavier from the 24V thruster board.

Alison suggested that all future PCBs avoid the use of 90º angles in their traces.

Alison agreed to check the KiCAD design of the updated PCB.

[c-bash]

Note: The capstone student who designed the PCBs has uploaded the relevant KiCad files here: PCBs

[smuzika]

New design includes Schottky diodes and octocoupler. Octocouplers purchased did not work and therefore the octocoupler was bypassed. Future designs should account for different octocoupler.