Power Tests

The EPS board is designed to be powered from the battery inputs through pairs of pins POS1&2 (J15 & J17) and NEG1&2 (J16 & J 18) using the battery saddle apparatus or directly powered through the MPB+ (J19) and BAT- (J20 & J21).

Unless testing the battery pack, normal powering procedures will use wired connections to pins MPB+ (J19) for the positive and BAT- (J20) for the negative leads.

Ensure the power supply has a current limit set to a reasonable boundary fro the desired test which in most cases will be 200mA before supplying power and that the clips used to power are not in contact with any other surfaces.

Before supplying power first ensure the RBF jumper is connected between pins J36 and J34 and the flightswitch is engaged by removing the jumper between J37 and J35. Once power is supplied, install the flightswitch jumper (disengaging the switches) and remove the RBF jumper.

Power Avionics Test Report

Start Date:

TBD

End Date:

Part Name:

Application:

Quantity:

1- Visual Inspection

Item

Test Item

Visual Inspection

Test Specification

Inspect the PWBs for any deformation, discontinuity in visible traces, and cracks on the boards. For PWAs, look for missing components, misplaced components and cracked/ broken/ bent components.

Judge Criteria

There shall be no such defects or flaws stated in the test specifications in any of the received boards.

Samples

3 PWAs

Test Period:

Test Equipment:

Major Problem:

Warning:

Recommendation:

Verification Activities:

Board Assembly:

TBD

EPS boards (3 PWAs)

N/A

Use the ESD safe mat for all these inspections

Take Dated Pictures

N/A

UMS-0587-FM

Raw Data:

2- Measurement of Physical Characteristics

Item

Test Item

Measurement of physical characteristics

Test Specification

The width and the height of the board must be measured and recorded. For the PWBs, the thickness of the boards must be recorded and for PWAs, as well as board thickness, the height of the highest component must be measured and recorded.

The mass of all the boards must be measured and recorded.

Judge Criteria

Width: 90±0.25 mm

Height: 90±0.25 mm

Thickness: 1.52±0.25 mm

Highest component:

XX±0.1 mm

Mass: XX±1 gr

Samples

3 PWAs

Test Period:

Test Equipment:

Major Problem:

Warning:

Recommendation:

Verification Activities:

TBD

EPS boards (3 PWAs)

---

Use the ESD safe mat for all these inspections

None

Raw Data:

Board Assembly:

UMS-0587-FM

3 - Deployment Sequence Test

Item

Test Item

Test the functionality of the 300 second timers, non-volatile latches and the Remove before flight pin

Test Specification

This test is to verify that:

The redundant 300 second deployment timers work to prevent the flow of power and will not allow premature function of the spacecraft.
The volatile latches will hold their value after a single event upset.
The Remove Before Flight (RBF) pin disengages power to the bus while inserted.

Judge Criteria

The overall output of the timers shall turn no earlier than 300 seconds. Volatile latches shall keep their values after the board resets. RBF prevents power deleivery while inserted

Samples

3 PWAs

Test Period:

Test Equipment:

Major Problem:

Warning:

Recommendation:

Verification Activities:

Board Assembly:

February, 2026

EPS board assemblies, power supply, multimeter, logic analyzer

N/A

Use the ESD safe mat and gloves for all these inspections

None

R-LIB-PWR-035

UMS-0587-FM

Notes:

FM Analog Timers are 300 seconds (5-minutes) instead of 100 seconds (EM).
The Non-Volatile Latches (NVL) Auxiliary Power Bus (APB) and Main Power Bus (MPB) when written shall keep their state in case of brownout to recover immediately. Thus the test is to show the enable pins (T5 and T6) remain high after powering down.
Software additionally uses a software clock as a third redundancy input to begin the operations once the RBF has been removed. This timer may optionally be set to a longer period to hold if more timer is required to hold after deployment.
"Power Draw" in this term can be measured from the current draw on the power supply. While the flightswitch (FSW) is engaged (unplugged) the draw shall be 0. Record current draw throughout testing.
Use of the programmer may be required to flash new firmware to the MCU. For more information on connecting the programmer refer to the Flash Procedures. Be aware that the programmer can cause observation bias and behave differently when plugged into the circuit, thus it is advised to flash, remove and power cycle before testing.

Detailed Instructions:

Connect the test points T3, T4, T5, and T6 to oscilloscope or logic analyzer and start capturing.

T3: Analog timer 1
T4: Analog timer 2
T5: Auxiliary power enable (output of the latch)
T6: Main power bus enable (output of the latch)
Optionally also T7: Auxiliary power 3.3V & T9: Auxiliary power 5V

Power the board using the Board power-up procedure but leave the RBF in and the FSW out (engaged).

At this point, no current should be provided to the system and all lines should be pulled low.

Disengage the FSW by inserting the jumper across pins J35 and J37.

This will allow power to flow to the auxiliary power bus which allows the timer circuit to activate. You may see fluctuations in the test points

With the RBF still engaged, wait for the timer period to show that no power will be delivered.

Removing the FSW (re-engaging power) should remove all draw from the system.
This test scenario would emulate moving the assembled satellite into the deployer before RBF is removed.

Remove the RBF while the FSW are disengaged, wait for the timer period to ensure the power is delivered.

T3 & T4 shall pulse and the main power bus latch T6 shall read high.
Re-inserting the RBF before the timers have pulsed shall restart the analog timers.

Once the system is powered, temporarily remove power from the supply and return it quickly. The main power bus should recover high and resume full power delivery.

This is to simulate a temporary brownout in the system. Removing the FSW is also an acceptable form of removing power.

Below, we can see the probed signals for Timers output and Reset.

Results & Raw Data:

Start of test, RBF is inserted.

After 150 seconds, RBF is removed. The power is still off.

100 seconds after removing the RBF, the satellite is powered on.

4 - Watchdog Timer Test

Item

Test Item

Test the watchdog timer for the microcontrollers.

Test Specification

Follow the instructions provided below for all 2 WDTs on the power board.

Judge Criteria

the WDT shall initiate a reset for the MCU if it doesn’t detect a pulse on the heartbeat pin for longer than 1.5 seconds.

Samples

3 PWAs

Test Period:

Test Equipment:

Major Problem:

Warning:

Recommendation:

Verification Activities:

Board Assembly:

TBD

EPS board assemblies, variable power supply, fixed 5V power supply,

N/A

Use the ESD safe mat for all these tests

None

UMS-0587-FM

Notes:

Use watchdog testing code configurations for testing the watchdog timers.
- The code used will simulate a potential brownout by stopping the constant watchdog signal coming from the respective microcontroller. In doing this, the watchdog circuit will detect the lack of pulse and send a reset signal to the micro controller restarting the code and the pulsing signal along with it.
the watchdog solderable jumper pins must be connected to test the watchdog testing code configuration as shown in the following images. These same solderable jumpers must be unsoldered to flash code onto the device as the process will be interrupted by the watchdog resetting.
Before flight/assembly the solderable jumper should be soldered to ensure the watchdog operation.
Instructions are the same for each circuit, but use different pinouts, so examine the board carefully to know which pins are required for inspection. Consider using the schematics to confirm which pins are being measured.

Detailed Instructions:

1. Find the Watchdog circuits input (WDI) and output (WDO) pin as shown in the circuit diagram and photos. Probe the pins using a logic analyzer carefully to not short another pin.
2. Power the board though the Board power-up procedure.
3. Run the WTD testing code and record the time to reset and the respective logic analyzer output.

Timer Circuit Watchdog

Main Processor Watchdog Circuit

Watchdog 1 is shown below:

Watchdog 2 is shown below:

Raw Data:

5 - Bus Inhibit Test

Item

Test Item

Test the main power bus to verify that the positive line can be switch on/off

Test Specification

By programming the digital timer and logic MCU, turn the SSR-EN on and measure the voltage at the MPB pins

Judge Criteria

The MPB voltage shall be equal to the battery voltage after the power bus inhibit is released.

Samples

3 PWAs

Test Period:

Test Equipment:

Major Problem:

Warning:

Recommendation:

Verification Activities:

TBD

EPS board assemblies, variable power supply, multimeter

N/A

Use the ESD safe mat for all these tests

None

R-LIB-PWR-036 [5388]

Board Assembly:

UMS-0587-FM

Bus inhibit active. the voltage at output is close to zero even though input voltage is 6.4V.

Bus inhibit released. the voltage at output is equal to input voltage at 6.4V.

6 - Ground Inhibit Test

Item

Test Item

Test the main power bus to verify that the ground leg can be connected/disconnected from battery negative terminal

Test Specification

By programming the digital timer and logic MCU, turn the APB-EN on and measure the voltage between the GND and battery negative terminal. It will show zero volts when the ground leg is properly connected.

Or by connecting the flight switch to battery negative, the ground will connect to battery negative.

Judge Criteria

close to zero ohms between ground and battery negative terminal shall be measured when inhibit is released.

Samples

3 PWAs

Board Assembly:

UMS-0587-FM

the 3 switches dedicated to deployment separation are annotated in this image.

Ground inhibit separating the connection between battery negative terminal and power GND

Ground inhibit connecting battery negative terminal to power GND.

7 - Ideal Diodes and DET Switches Test

Item

Test Item

Test the functionality of Ideal diodes and DET switches and the current sensors.

Test Specification

Follow the instructions provided below for all 7 inputs of the solar arrays to verify their functionality.

Judge Criteria

For all 7 inputs the following shall be verified:

*Ideal diodes prevent flow of current when Vin<±0.05V

*Current sensors accuracy =±50 mA

*When EN is off: current<10mA

Samples

3 PWAs

Test Period:

Test Equipment:

Major Problem:

Warning:

Recommendation:

Verification Activities:

Board Assembly:

TBD

EPS board assemblies, variable power supply, electronic load, multimeter, EM battery pack

N/A

Use the ESD safe mat for all these inspections

N/A

R-LIB-PWR-029, R-LIB-PWR-030

UMS-0587-FM

Notes:

Pictured is a sample of 1 set of DET switch, ideal diode and current sensor.

Detailed Instructions:

Connect the battery pack or additional power supply to the board main power using the Board power-up procedure
Find the solar panel inputs on the left side of the board*. The connectors numbered J1-J7 are for the positive side and J8-J14 are for negative side. We will refer to these as ‘power input pins’

Add a break point before and run the power controller script "TestSolarArrayScript()" and follow the instructions as below and within the code. Carefully stepping through single lines at a time to verify values. The script will toggle the solar array inputs on/off and read the current measurement feedback in the code. Write down the results.

Follow these steps to verify the function of ‘Ideal diodes’

Measure the battery pack voltage. We’ll call this Vbatt
Set the power supply voltage to 6.4 V (we’ll call this Vsupply) and set the current limit to 0.2 A and turn off the power supply
Connect the power supply to the power input pins
Turn on the EN pin through the script.
Turn on the power supply
Read the current measurement from the test script.
Change the power supply voltage in the range of (5V~7.2V). Read the current value. This value shall represent 0A for Vsupply< Vbatt and a positive current for Vsupply> Vbatt. The conversion factor is 1V/A.

Follow these steps to verify the function of ‘DET switches’

Measure the battery pack voltage. We’ll call this Vbatt
Set the power supply voltage to 7.2 V (we’ll call this Vsupply) and set the current limit to 0.5 A and turn off the power supply
Connect the power supply to the power input pins
Turn off the EN pin using the script.
Read the current measurement through the script.
Turn on the power supply
Read the current value. No current shall pass at this moment
Turn on the EN pin using the script.
Read the current value. A positive current shall pass at this moment. The conversion factor is 1V/A

Follow these steps to verify the function of ‘Current sensors’

Measure the battery pack voltage. We’ll call this Vbatt
Set the power supply voltage to 7.2 V (we’ll call this Vsupply) and set the current limit to 0.5 A and turn off the power supply
Connect the power supply to the power input pins
Turn on the EN pin using the script.
Read the measured current through the script.
Turn on the power supply
Read the current value and compare it to the value shown of the power supply’s ammeter. The two values shall agree with an error less than 5%. The conversion factor is 1V/A.

Results & Raw Data:

8 - Temperature Sensors Test

Item

Test Item

Test the temperature sensors on the power subsystem.

Test Specification

Follow the instructions provided below for all 7 temperature sensors to verify their functionality. Use a thermometer as a truth measurement and compare the measured temperatures.

Judge Criteria

The temperature readings shall agree with the thermometer value with 5% accuracy.

Samples

3 PWAs

Test Period:

Test Equipment:

Major Problem:

Warning:

Recommendation:

Verification Activities:

Board Assembly:

TBD

EPS board assemblies, variable power supply, test thermistor, digital thermometer

N/A

Use the ESD safe mat for all these tests

Will require re-testing once the solar wings are built.

R-LIB-PWR-031 [5366]

UMS-0587-FM

Notes:

THERM_1 and THERM_2 measure battery saddle temperature, THERM_3 through THERM_6 measure solar panel temperatures, and THERM_7 measures power board's internal temperature. Measure THERM_7 by placing the true temperature probe on the yellow switch R43.

Preamble:

This test is to measure the accuracy of the thermistors and the GPIO that collects that information. For this test we are using a coupled thermistor (UMS-0045 and maybe find a picture) on each of the 6 outboard pins, however the solar panels will use a different thermistor on board (UMS and Picture would be cool).

This test must be repeated with the correct thermistors once the solar wings are constructed, but to demonstrate the GPIO and code, this test will first use the battery saddle thermistor for all pins except the on-board thermistor.

Detailed Instructions:

Power on the board main supply using Board Power-on Procedure.
Programming the STM32 chip debug and run the the script: "test_thermistors_script()" within main.c. Ensure a breakpoint is set before the script and step through one instruction at a time. follow these instructions as well as those within the script comments.
Running (debugging) the code, we are able to see in the variable window the "temp_C" variable once it has read the temperature. Either double click it, or watch it as an expression. Record this value.
Using the Perfect Prime: DataLogger Thermometer, we will be measuring the true temperature with this device. To use the thermometer, place the probe on the end of the thermistor for the best comparison.
Once recorded, carefully grab the test thermistor at the base and wait 15-20 seconds before continuing to the test to allow the temperature to balance.
Repeat steps 3-5 for each thermistor.

Result & Raw Data:

9 - Heater Test

Item

Test Item

Test the battery heater output from the power system

Test Specification

instructions below to verify the battery heater functionality and use a digital thermometer to measure the output.

Judge Criteria

???

Samples

3 PWAs

Test Period:

Test Equipment:

Major Problem:

Warning:

Recommendation:

Verification Activities:

Board Assembly:

TBD

EPS board assemblies, variable power supply, test heater

None

Use the ESD safe mat for all these tests, Do not touch active heater.

None

???

UMS-0587-FM

Notes:

Minco HK6908 Heater used for battery saddle is controlled from a load switch but not can controlled and no current or fault sensing, more simply just by GPIO and powered through the load switch regulator. The heater is rated to 100C so do not test directly on rubber ESD mat out of caution for melting it.

Detailed Instructions:

Power on the board main supply using Board Power-on Procedure.
Programming the STM32 chip debug and run the the script: "test_heater_script()" within main.c. Ensure a breakpoint is set before the script and step through one instruction at a time. Follow these instructions as well as those within the script comments.
Running (debugging) the code, we are able to pause after powering on the heater. Wait for the heater to stabilize (120 seconds)
Using the Perfect Prime: DataLogger Thermometer, we will be measuring the true temperature with this device. To use the thermometer, place the probe on the heater for the best measurement.
At the same time use a multimeter in series to measure the current draw of the heater.
Once recorded, continue with the script that turns off the heater.

Result & Raw Data:

10 - Inter-Subsystem Communication Tests

Item

Test Item

Test the power electronic board to verify it can communicate with CDH through CAN and with CCLSMs through AUX_CAN

Test Specification

Verify that 2-way communication between power and CDH and CCLSMs can be achieved.

Judge Criteria

data can be exchanged between the transmitter and receiver and in case of corrupted data, retransmission of data is supported.

Samples

3 PWAs

Test Period:

Test Equipment:

Major Problem:

Warning:

Recommendation:

Verification Activities:

Board Assembly:

TBD

EPS board assemblies, CCLSMs, CDH board, variable power supply, fixed 5V power supply,

None

Use the ESD safe mat for all these tests

None

R-LIB-PWR-039 [5402]

UMS-0587-FM

Notes:

We can see that when the software attempts to communicate with the CDH, CAN signals appear on the logic analyzer and the appropriate breakpoint gets triggered on the CDH side to indicate that a proper data transfer was completed.
By watching the CCLSM_DATA variable on the power controller or the cclsm_data variable on the load switch we can compare values sent to/from the devices. by matching these variables we can validate the boards communicate through the AUX_CAN.

11 - Load Switch (CCLSM) Test

Item

T10

Test Item

Test the functionality of load switches and the current sensor integrated to it

Test Specification

Follow the instructions provided below for all 8 load switches to verify they can switch the power on and off when needed and limit the current if a short circuit happens.

Judge Criteria

For all 8 load switches the following shall be verified:

*Ideal diodes prevent flow of current when Vin<±0.05V

*Current sensors accuracy =±50 mA

*When EN is off: current<0.1 mA

Samples

3 PWAs

Test Period:

Test Equipment:

Major Problem:

Warning:

Recommendation:

Verification Activities:

Board Assembly:

TBD

EPS board assemblies, variable power supply, electronic load, multimeter, EM battery pack

None

Use the ESD safe mat for all these tests

None

R-LIB-PWR-034 [5379] , R-LIB-PWR-022,

UMS-0587-FM

Detailed Instructions:

Power up the board using the Board power-up procedure
Verify the communication to CCLSMs through AUX_CAN bus
COMS CCLSM shall be able to provide a maximum of 12 W (1 A at 12 V) of power for 350 seconds to accommodate COMS transceiver's required power of 10.32 W (860 mA at 12 V) for 307.2 seconds.
CDH CCLSM shall be able to continuously provide a maximum of 1W (156 mA at 6.4 V) of power to accommodate CDH's required power of 0.74W (115 mA at 6.4 V)
ADCS CCLSM shall be able to continuously provide a maximum of 1W (156 mA at 6.4 V) of power to accommodate ADCS's required power of 0.74W (115 mA at 6.4 V)

Results & Raw Data:

12 - Battery Interface Test

Item

T11

Test Item

Test the functionality of the coulomb counter and the battery protection circuits

Test Specification

This test is to verify the safe charge and discharging of the battery pack as well as testing the coulomb counter’s ability to interface and send/receive data via the (pins)

Judge Criteria

Battery voltage shall not exceed 7.3V in charging and shall be kept higher than 4V in discharging.

The coulomb counter values shall agree with the battery specifications

Samples

3 PWAs

Test Period:

Test Equipment:

Major Problem:

Warning:

Recommendation:

Verification Activities:

Board Assembly:

TBD

EPS board assemblies, EM battery pack, Arduino board, power supply, multimeter

N/A

Use the ESD safe mat for all these inspections

None

R-LIB-PWR-019 [5327]

UMS-0587-FM

Notes:

The protection circuit was triggered when the battery voltage was becoming higher than 7.4 V during charge or less than 4.2 V during discharge. Note that the coulomb counter was able to measure the coulombs in and out of the battery and because of the lower discharge current used in the test, the number of the coulombs out is less than the coulombs in.

Detailed Instructions:

Protection Circuit:
1. Connect 2 power supplies at the same input voltage of 6.4V with a maximum current draw of 0.5A to the board’s battery input pins.
2. Adjust both power supply voltage inputs at the same time in a range from 3V to 8V and take note of which voltages are within the powered range.

Coulomb Counter:
1. Connect a power supply at 6.4V with a maximum current draw of 0.5A to the board's main power input pins.
2. Connect a battery pack to the board's battery input and measure its voltage (using code)
3. Run the testing script which charges the battery for a set period of time (1 minute) and read the output of the coulomb counter.
4. Connect a controlled load of 0.3A to the board so simulate discharging and run the associated testing script for a set period of time (1 minute) which will read the coulomb output.

Results & Raw Data:

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