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Front | Rear |
---|---|
Peripheral Displays & Cameras (Use a simple circuit to distribute the current) | Solar Master (Front) |
Steering Board | Solar Master (Rear) |
Pedal Board | Rear View Camera |
Fan | Fan |
Spare | Telemetry |
Spare | Charger Interface |
Potential Parts
Part Number | Load Current | Rds On | Number of Outputs | Analog Current Sense |
---|---|---|---|---|
TPS2H160BQPWPRQ1 | 2.5A | 155mOhm | 2 | |
BTS71202EPAXUMA1 | 2A | 61mOhm | 2 | +/-30% @ 50mA, +/-11% @ 500mA |
AUIPS7091GTR | 1.5A | 80mOhm | 1 | +/-8% @ 50mA, +/-3% @ 500mA |
AUIPS7081RTRL | 2A | 55mOhm | 1 |
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Current Limit: < 20A @ 12-13.5V
Front | Rear | |
---|---|---|
Spare | Front Power Distribution (around 16A at the maximum) | |
Spare | BMS Carrier (Master & Slave) (due to high inrush current to the relays) | Front Power Distribution (around 16A at the maximum) |
Potential Parts
Part Number | Load Current | Rds On | Current Mirror Error |
---|---|---|---|
BTS70041EPPXUMA1 | 15A | 4.4mOhm | ± 8% @ 10 - 15A |
AUIR3313STRL | 23A (Adjustable) | 5.5mOhm | ± 5% |
BTS70021EPPXUMA1 | 21A (Fixed) | 2.6mOhm | ± 5% |
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The target power consumption of MSXIV's LV system is 20 W. A reasonable accuracy will be the +/- 0.1% of the total power. Given the supply voltage will be 12-13.5 V, the current sensing circuit should be more accurate than +/- 1.5 mA.
Mathinline | ||
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Locations
Given the HSD will be responsible for disconnecting the load when it is shorted to ground, there is no safety advantage for high side current sensing. There are three locations for the current sense resistor:
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- High-Side
- High immunity to ground disturbance
- The common-mode voltage tolerance of the differential op-amp must be greater than 12V
- HSD Current Mirror
- A HSD built-in current mirror with high gain plus a current sense resistor should use less power than the low-side sensing (needs proof)
- The accuracy is around +/- 30% for low current (< 100 mA)
Block Diagram
Ports
Front
Board | Nom. Current (A) | Max. Current (A) | Connector | HSD |
---|---|---|---|---|
Peripheral Displays & Cameras | 0.278 | 0.329 | Light | |
Front Lights Board | 1.889 | 4.163 | Heavy | |
Steering Board | 0.017 | 0.071 | Light | |
Pedal Board | 0.013 | 0.067 | Light | |
Center Console | 0.952 | 2.146 | Light | |
Horn | 0 | 8 | Heavy |
Rear
Board | Nom. Current (A) | Max. Current (A) | Connector | HSD |
---|---|---|---|---|
Motor Interface | 0.179 | 4.958 | Light | |
BMS Carrier (Master & Slave) | 0.814 | 19.800 | Heavy | |
Solar Master | 0.150 | 0.482 | Light | |
Rear Lights Board | 0.022 | 2.879 | Heavy | |
Rear View Camera | 0.5 | 0.5 | Light | |
Charging Interface | 0.026 | 0.133 | Light | |
Front Power Distribution | 3.250 | 15.97 | Heavy |