Power Distribution Board Manual
- Griffin Ross
This document is a manual for use of the Power Distribution Boards (PDBs).
For information about the power distribution board and its design, refer here: Power Distribution Board .
WARNING: The Power Distribution Board uses, and is the protection circuitry for, lithium-ion batteries. Do not leave the Power Distribution Board unattended while charging. Do not detach the batteries from the Power Distribution Board. Store the Power Distribution Board in a lithium battery safety bag.
WARNING: The Power Distribution Board is intended to control arming and disarming of pyrotechnic systems. Follow procedures as specified in this manual to ensure safe operation of such systems.
Physical Board
A PDB consists of a board, its two (permanently) attached batteries, and a WiFi antenna.
Dimensions:
Item | Dimensions |
|---|---|
Board | 50mm x 45mm x 14mm |
Battery | 50.8mm x 33.5mm x 5.9mm |
Antenna | 31mm x 13mm x 1mm |
Starting at the bottom left of the PDB there are 2 sets of DIP switches. The lower switches are used to turn on/off the Main and Pyro power supplies. Both switches should be off (left) when the board is not in use. The upper switches are used to enable or disable the optional 5V and Adjustable power outputs.
In the bottom center are 2 green lights which indicate whether the Main and Pyro supplies are turned on. These should be off when the board is not in use.
In the bottom right corner is a warning buzzer that sounds when the pyro output is enabled (armed).
Above this are two buttons used for programming or resetting the board.
In the center-right is the pyro output and its arm warning light. The warning LED will light up red when the system is armed. The pyro output is a high-side switched output that should be connected to flight computers as a pyro battery would be. The pyro output is supplied directly from the pyro battery, which is 3.7V nominal.
Along the top of the board are the 4 flight power outputs. The CELL output is always active when the board is on and provides a raw output from the flight battery. The 3.3V output is always active when the board is on and provides a regulated 3.3V output. The 3.3V output is fused to 1A to prevent an external device from shorting out the supply, which is also used by the on-board processor. The 5V and adjustable outputs can be enabled or disabled using their enable DIP switches, and provide regulated outputs. The adjustable output can be adjusted with the trimpot near the top left.
The WiFi antenna uses a W.FL (MHF3) connector and has an adhesive backing.
WARNING: Do not turn on the Power Distribution Board without the WiFi antenna attached. Doing so can cause permanent damage to the WiFi module.
WARNING: The antenna cable is very fragile. Securely mount the antenna and protect its cable.
Web Interface
The Power Distribution board includes a web interface used to see the status of the batteries and to control the pyro output. To open the web interface, connect to the powerboard’s WiFi network, then go to the address “192.168.4.1” in a web browser.
WiFi SSID: “Powerboard n” WiFi password: “iusucks1234”
On the left and right, information about both batteries is shown.
State-of-charge data has the potential to be unreliable, so always verify the battery voltage displayed.
In the center, the status of the pyro output is shown. When the pyro output is off, the arming status displays as “SAFE”. When the pyro output is on, the arming status displays as “ARMED”.
At the bottom center, the user can toggle the pyro output. To toggle the pyro output, type “CONFIRM” in the box, then press the Arm/Disarm button.
Instructions for Use
Turning on the PDB
To turn on the PDB, use a small instrument to toggle the power switches to the right. Confirm both green power lights are on. If the 5V or adjustable voltage outputs are desired, enable them by toggling their switches to the right. If the red arm light is on or the alarm is sounding, make sure to disable the pyro output before connecting the PDB.
Wiring to the PDB
Before wiring, ensure that the PDB is disarmed. Also, remember that only one PDB should be used per flight-critical board for redundancy purposes. To connect the pyro output, treat its output like a battery and refer to your flight computer’s manual. Next, wire the desired flight voltage output to the flight computer. If the flight computer is meant to be powered by a battery, simply wire the raw cell output to the flight computer. The regulated outputs can be used if a regulated voltage is needed or the cell output is already occupied.
Connecting to the PDB
With the PDB turned on, go to your device's WiFi settings. The PDB’s SSID is of the form “Powerboard n” where n is a number corresponding to each unique board. Connect to the network. Next, open a browser and go to “powerboard.local”. If this does not work, try connecting using the IP address: “192.168.4.1”.
Arming/Disarming the PDB
To arm the PDB, start on the PDB’s webpage. In the text box, enter “CONFIRM” and press the arm/disarm button. If successful, the status on the website will change, and the warning light and alarm on the board will toggle. The PDB is equipped with a hardware delay circuit that will only allow the pyro output to be enabled or disabled after a delay of approximately 7 seconds. This allows for the user to have time to retreat in the case of accidental arming while in proximity to the system.
WARNING: The PDB features a red warning LED and warning buzzer. If either are active, consider the board to be armed and take appropriate precautions.
WARNING: When the PDB is disarmed and the warning signals stop, the board remains armed for ~10 seconds. Wait at least 30 seconds after disarming before considering the board safe.
Charging the PDB
To charge the PDB, connect the USB-C connector to a charger. When charging, the PDB can use up to 5W of power. To check the status of charging, use the PDB’s webpage.
After Use
When finished using the PDB, first disarm it, then turn off all power/enable switches. If storing the PDB for long periods, first fully charge the batteries. Take appropriate precautions to protect the PDB’s lithium-ion batteries.