Supplemental Monitoring Hat
Status |
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Owner | @Abigail Parsons |
|---|---|
Approver | @Ravi Shah |
Due date |
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GitHub | |
BOM |
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Due Dates:
Requirements/Considerations -
Component Selection -
Initial Schematic -
Initial Layout -
Rev. A Ordered -
Firmware/Testing -
Description/Purpose
PCB that measures the voltage and current of the supplemental battery with an output regulator
Requirements
Electrical Regulation & Safety
Stable regulated output → Prevents downstream circuits from brownout due to battery droop.
Overcurrent protection → Regulator should protect against overcurrent nominally, but in case of regulator fail / short, include a fuse before regulator for extra protection (10-15A)
Undervoltage cutoff → Protects NiMH cells from deep discharge.
Reverse polarity protection → Guards against incorrect wiring / use.
Measurement & Monitoring
Pack voltage monitoring → Monitoring both before and after regulator. Before for UV cutoff and protection, after for downstream circuit Power Good validation / regulator stability (logic & this with PGood on Vicor itself).
Input and output current sensing → Enables efficiency calc + fault detection. Before for fault detection (if we see a good voltage on Vicor input end but its not drawing any current → vicor is prob cooked), after for total LV power consumption reading + overcurrent protection.
Pack internal temperature → Prevents overheating of cells under load.
SoC?
Indicators
7-segment, 3-digit → Pack voltage (before regulator), format
XX.X V.Green, solid → Power OK / Reg output within tolerance (normal).
Yellow, solid → Battery Voltage Low
Red, solid → Fault (temp, over current, egregious low batt voltage).
Application Note
Context
Location of the board: On top of the LV Carrier PCB
Connection List
# | Name | Type | Part Number |
|---|---|---|---|
J6 | Input/Output | UTSVT_Connectors | 524652470 |
Main
Schematics
Circuit Components
Current Sense Op Amplifiers: (Bidirectional): INA241A5 : 200V Gain
Dual Op Amplifiers: TLV9002QDRQ1
Seven Segment LED: CA56-11GWA
8-bit Shift Register: 74HC595N
Reference Voltage: REF35102QDBVR
Layout
Github link: https://github.com/lhr-solar/PS-LVCarrierPCB/tree/main
PCB:
3D Model