notes: update notes with design of EPS
This commit is contained in:
143
README.md
143
README.md
@ -1,57 +1,42 @@
|
||||
# BUTCube
|
||||
Modules:
|
||||
- Solar panels (XY, Z) (not in stack)
|
||||
- EPS
|
||||
- Flight Computer
|
||||
- Mission computer
|
||||
- Communication
|
||||
- Sun sensor module (not in stack)
|
||||
- ? Attitude control
|
||||
- Access port module (not in stack)
|
||||
|
||||
# Solar cells
|
||||
|
||||
Digi-key filter: https://www.digikey.nl/products/en?FV=-5|23585
|
||||
|
||||
Calculations for space are calculated with 1 mm space between panels
|
||||
In center of panel there should be attitude determination module with minimal size od 25mm x 25mm
|
||||
All calculation are only for one side of satelite
|
||||
# Solar panels
|
||||
|
||||
## Solar cells
|
||||
#### SM141K04L
|
||||
- Link: https://www.digikey.nl/short/fvpwbf4h
|
||||
- Panel count: 10 (2S 5P)
|
||||
- Maximal power: 1.23 W
|
||||
- Voltage: 4.46 V
|
||||
- Dimensions: 29 x 23 mm (89 x 95 mm)
|
||||
- Weight: 3g (30g)
|
||||
- Configuration: 4 x 3
|
||||
- Price (for 1 side): 28 € (750 CZK)
|
||||
|
||||
#### KXOB25-05X3F
|
||||
- Link: https://www.digikey.nl/short/hdrrmtq3
|
||||
- Panel count: 32 (4S 8P)
|
||||
- Panel count: 8 (2S 4P)
|
||||
- Maximal power: 0.98 W
|
||||
- Voltage: 6.68 V
|
||||
- Dimensions: 23 x 8 mm (95 x 89 mm)
|
||||
- Weight: 0.5g (17g)
|
||||
- Configuration: 10 x 4
|
||||
- Price (for 1 side): 47 € (1229 CZK)
|
||||
- + Reflow solderable
|
||||
|
||||
#### SM141K06LV
|
||||
- Link: https://www.digikey.nl/short/d80rrj7t
|
||||
- Panel count: 6 (2S 3P)
|
||||
- Maximal power: 1.10 W
|
||||
- Voltage: 6.7 V
|
||||
- Dimensions: 45 x 22 mm (91 x 91 mm)
|
||||
- Weight: 3g (18g)
|
||||
- Configuration: 2V 2H 2V
|
||||
- Price (for 1 side): 27 € (720 CZK)
|
||||
- Voltage: 4.46 V (MPPT)
|
||||
- Dimensions: 29 x 23 mm
|
||||
- Weight: 3g (24g)
|
||||
- Price (for 1 side): 28 € (750 CZK)
|
||||
|
||||
#### SM141K04LV
|
||||
- Link: https://www.digikey.cz/short/r589mmbj
|
||||
- Panel count: 8 (2S 4P)
|
||||
- Maximal power: 0.98 W
|
||||
- Voltage: 5.52 V
|
||||
- Dimensions: 45 x 15 mm (81 x 95 mm)
|
||||
- Voltage: 4.46 V (MPPT)
|
||||
- Dimensions: 45 x 15 mm
|
||||
- Weight: 2.5g (20g)
|
||||
- Configuration: 2V 4H 2V
|
||||
- Price (for 1 side): 28 € (750 CZK)
|
||||
|
||||
## Solar module
|
||||
- PCB with size cca 96x96 mm
|
||||
- In center of module is hole for another module (40x40 mm without corners)
|
||||
- Two sizes of solar panel PCBs
|
||||
- Z - 100x100 mm with cutouts in corners for rails
|
||||
- X,Y - 100x83
|
||||
- In center of module is hole for another module
|
||||
- Approximate size of module is 46x30 mm
|
||||
- Mounting to frame is via 4 bolts in corners of board
|
||||
- Integrated components: Optodiode, temperature measuring IC
|
||||
|
||||
## Sensors
|
||||
@ -59,15 +44,85 @@ All calculation are only for one side of satelite
|
||||
- Photo diode:
|
||||
- VEMD5510C - 550nm (450-750) - visible
|
||||
- VEMD5060X - 800nm (500-1000) - visible + IR
|
||||
- VEMD5160X - 850nm (750-950) - IR
|
||||
- VEMD5160X - 850nm (750-950) - IR (used)
|
||||
- ADC for photodiode: ADS7142
|
||||
|
||||
# Cables
|
||||
- https://www.digikey.cz/product-detail/en/adafruit-industries-llc/3165/1528-1733-ND/6193585
|
||||
- https://www.digikey.cz/product-detail/en/adafruit-industries-llc/3167/1528-1735-ND/6193587
|
||||
- https://www.digikey.cz/product-detail/en/adafruit-industries-llc/3168/1528-1736-ND/6193588
|
||||
- https://www.digikey.cz/product-detail/en/adafruit-industries-llc/3164/1528-1732-ND/6193584
|
||||
|
||||
- 30AWG resistance 0.3R per meter
|
||||
- Length in CubeSat cca 10-15 cm
|
||||
- Power loss in cables is 0.5mW in peek (0.05% per solar module)
|
||||
- Similar power loss will be at cable connectors
|
||||
|
||||
# Stack connector
|
||||
- [https://cz.mouser.com/ProductDetail/200-SSQ12002TD]
|
||||
- 2x20 pins
|
||||
- Limits board to thickness of 1mm or less
|
||||
- Board spacing: 8.51 mm
|
||||
|
||||
# EPS
|
||||
- Two identical modules on one board
|
||||
- Both connected to stack connector
|
||||
- Other board could be connected to both or one of then
|
||||
- Power oring must be solved
|
||||
- Connected to main CAN
|
||||
|
||||
## Power output
|
||||
- 3 regulated and monitored power rails - 1V8, 3V3, 5V
|
||||
- Output regulator - TPS63002DRCR
|
||||
- 0.8A (boost) up to 1.2A (buck) output
|
||||
- 2.2 uH coil
|
||||
- 1 unregulated output of battery, monitored
|
||||
- Monitoring via current sensors (INA??)
|
||||
|
||||
## Battery
|
||||
- Limit for CubeSat is 50Wh
|
||||
- Suggested battery has form factor 21700
|
||||
- One battery per EPS
|
||||
- Battery is mounted in battery holder
|
||||
- Keystone 1122 - 1122
|
||||
- Probably additional fixation is requested
|
||||
- Selected battery - https://www.conrad.cz/p/samsung-inr21700-50e-specialni-akumulator-21700-flat-top-li-ion-akumulator-36-v-4900-mah-2114678
|
||||
- 3.6V, 4900mAh, 17.64Wh
|
||||
- EPS module has around 35Wh (well in limit)
|
||||
|
||||
## Battery heating
|
||||
- https://www.ges.cz/cz/odl-20r81-GES06914579.html
|
||||
- https://www.ges.cz/cz/odl-53r1-GES06914581.html
|
||||
- https://www.gme.cz/odporovy-drat-odp-kan02-3m
|
||||
- https://www.gme.cz/odporovy-drat-odp-kon03-3m
|
||||
|
||||
- Heating should be designed for power around 1-4W
|
||||
- With 5.4R/m and battery input source (3.7V) length of wire for 2W heating should be around 1.2m (current 0.5A)
|
||||
- 0.5A is probably to much, values around 0.2A are better -> 1W heating
|
||||
- For regulation could be used power switch with constant current regulation
|
||||
|
||||
# Access port module
|
||||
Connectors:
|
||||
- USB-C
|
||||
- data connected to mission computer or flight computer
|
||||
- power connected to EPS for battery charging
|
||||
- 2x SWD port for programing and debugging of Flight and Mission computer
|
||||
- main CAN bus connector
|
||||
- UART debug port
|
||||
|
||||
- Realized as stack of two PCB boards
|
||||
- Front acts only as cover for connectors
|
||||
- Connectors are mounted on rear board
|
||||
- Connectors are accessible via cutouts in frontz board
|
||||
- Rear board is mounted to front via column spacers
|
||||
|
||||
# Other parts:
|
||||
- LTC4415 - Dual ideal diode with ORing
|
||||
- MAX16171
|
||||
- MAX16171 - Ideal Diode Controller with Reverse-Current Protection
|
||||
- BQ25798 - solar battery charger with dual-input selector and MPPT, I2C, https://www.ti.com/product/BQ25798
|
||||
- BAT54W-G - Low drop shottky diode, solar blocking diode
|
||||
- BQ27421YZFT-G1A - Fuel gauge
|
||||
|
||||
|
||||
|
||||
|
||||
# Digikey orders
|
||||
https://www.digikey.cz/short/8nmn4tr3
|
||||
https://www.digikey.cz/short/d4n94tbz
|
||||
|
Reference in New Issue
Block a user