Subjects: Hardware , Assembly Guides
Use Cases: PCB Design & Assembly , Node Cluster Setup
Battery Card Assembly Guide
Table of contents
Introduction
See the How to Use Assembly Guides for detailed instructions.
In conjunction with the LCC Fusion LCC Fusion Node Card and a Node Bus Hub, the Battery Card is a critical component for the LCC Fusion Project, designed to keep your LCC nodes powered and portable. This card ensures reliable operation of your layout control system by providing a stable, rechargeable power source.
What It Is
The Battery Card utilizes a 3S Li-Po battery configuration, delivering a maximum output voltage of 12.6 V and a capacity of 1000mAh. It features integrated protection circuits, including overcurrent, short circuit, and low voltage safeguards, ensuring both the battery and your devices remain safe during operation.
When to Use It
Use the Battery Card to maintain continuous and portable power for your LCC nodes in the LCC Fusion Project. This is particularly beneficial when you need to:
- Ensure Uninterrupted Power: Keep LCC nodes running smoothly without relying on fixed power supplies.
- Enhance Portability: Make your LCC setup portable for demonstrations, testing, or temporary installations.
- Utilize Rechargeable Convenience: Easily recharge the battery via USB for repeated use.
Key Features
- Stable Voltage Supply: Provides consistent power for LCC nodes and components.
- Rechargeable: USB charging capability for convenience and ease of use.
- Comprehensive Protection: Integrated overcurrent, short circuit, and low voltage protections.
Applications in LCC Fusion Project
- LCC Node Power Supply: Reliable power for LCC nodes to ensure smooth operation.
- Portable Layout Control: Allows for the mobility of LCC nodes, ideal for demonstrations and temporary setups.
- Rechargeable Solution: Simplifies power management with easy recharging, enhancing the flexibility of your LCC system.
The Battery Card is an essential component for anyone looking to keep their LCC nodes powered and portable, ensuring the LCC Fusion Project operates efficiently and reliably in any setting.
- esp32_s3 - not defined
- jumper_caps - not defined
- lcc_fusion_node_bus - not defined
- lcc_fusion_node_card - not defined
- li_po_battery - not defined
- low_voltage_detection - not defined
For other terms, please refer to the full Terminology Guide.
Assembly and Component Placement
This section combines both the component specifications and the assembly instructions to ensure a smooth assembly process. Below is a comprehensive list of components, their placement on the PCB, and orientation details to assist you during assembly.
High-Level Steps for Assembly:
- PCB for the card can be ordered from any PCB fabricator using these Gerber Files.
- Clean PCB with alcohol to remove residue. See Cleaning_PCB for details.
- See also: Soldering Tips
- PCB Components - listing of components used for PCB assembly
- PCB Parts - listing of parts used for PCB assembly
Below is a list of the PCB components used for this card (see diagram before reference):
| Component Identifier | Count | Type | Value | Package | Purpose | Orientation |
|---|---|---|---|---|---|---|
| Batteries | ||||||
| BATT1, BATT2, BATT3 | 3 | Li-Po Battery | 500mAh, 1000mAh | 502535, 802540 | Batteries for powering Node Bus Hub | None (insure battery wire polarity matches socket silkscreen markings) |
| Capacitors | ||||||
| C1, C2 | 2 | Capacitor-Ceramic | 1uF, 50 V | 1206 X7R | Filtering for the charging IC | None |
| Diodes | ||||||
| D1, D3, D4 | 3 | Diode-Schottky | SS310 | SMA, SMD | Prevents reverse voltage | Cathode end has a white line and positioned towards PCB top edge |
| D2 | 1 | TVS Diode | SMAJ5A | SMA | Protects from high-voltage transients (>5 V) | Cathode end has a white line and positioned towards PCB top edge |
| ZD1 | 1 | Zener Diode | 9.1 V | 1206 SMD | Creates a reference voltage determining low battery | Cathode end has a white line and positioned towards PCB top edge |
| Fuses & Protection | ||||||
| F1 | 1 | Fuse-PTC Polymer | JK30 3A, 12 V (or more) | PTH | Protects from sustained overcurrent conditions | None |
| Connectors | ||||||
| J1, J2, J3, J4 | 4 | JST XH Socket | 2P, 2.54mm | PTH or Spring Terminal | Battery Connections | Position socket for battery wiring matches silk screen + and - markings |
| J5 | 1 | USB-C Socket | 4-Pin | SMD | Power input connector used for 5V charging of batteries. | Fits only one way |
| Indicators | ||||||
| LED1 | 1 | LED | Red | 1206 SMD | Low battery indicator (<9.1 V) | Reference back of LED, cathode positions downward on the PCB. |
| LED2 | 1 | LED | Green | 1206 SMD | Charging Indicator | Reference back of LED, cathode positions downward on the PCB. |
| LED3 | 1 | LED | Green | 1206 SMD | USB-C Power Indicator | Reference back of LED, cathode positions downward on the PCB. |
| Resistors | ||||||
| R1, R2 | 2 | Resistor | 47kΩ | 1206 SMD | Voltage Divider for charging circuit input | None |
| R3, R4 | 2 | Resistor | 10kΩ | 1206 SMD | Voltage Divider for charging circuit input | None |
| R5 | 1 | Resistor | 1kΩ | 1206 SMD | Current-Limiting for diode | None |
| R6, R11, R12 | 3 | Resistor | 1kΩ | 1206 SMD | Current-Limiting for LEDs | None |
| R7 | 1 | Resistor | 10kΩ | 1206 SMD | Voltage Divider for transistor input | None |
| R8 | 1 | Resistor | 47kΩ | 1206 SMD | Voltage Divider for transistor input | None |
| R9 | 1 | Resistor | 2kΩ | 1206 SMD | Current-Limiting for charging rate | None |
| R10 | 1 | Resistor | 10kΩ | 1206 SMD | Current-Limiting for transistor input | None |
| Voltage Regulators | ||||||
| U1 | 1 | IC | LM393 | SO-8, SMD | Used for detecting low voltage (<9.1 V) | Small dot (pin 1) positioned to upper right corner |
| U2 | 1 | IC | MCP73831 | SOT23-5, SMD | Controls charging current to batteries | Fits only one way |
| Transistors | ||||||
| Q1 | 1 | NPN Transistor | BSS138 | SOT233, SMD | Switches output off while charging | Fits only one way |
| Q2 | 1 | PNP Transistor | IRLML6402 | SOT233, SMD | Switches output off while charging | Fits only one way |
Tools Required
Safety Precautions
- See Safety Precautions.
Assembly Instructions
Below are the high level steps for assembly of the Audio Card:
See also: Soldering Tips
- Position the card with the edge connector tabs facing down (see image on right).
- When using a PCB stencil to apply the paste, align the stencil over the PCB using the 2 Tooling Holes located at the top and bottom of the card. There are very small holes with no labels or markings. Use a thick straight pin or wire for the alignment, pushing down into a soft foam surface to hold the pin/wire in place.
- Install (3) Li-Po batteries
- use tie strap thru holes to hold in place
-
- Connect Battery Card output to Power-CAN Card
- Install a wired JST XH plug to the battery out connector (J4)
- plug into the Power-CAN Card battery JST XH connector (J13)
| Designator (value) | Component | Required? | Orientation |
|---|---|---|---|
| C1, C2 | 1uF | Required | None |
| D1 | 9.1 V Zener | Required | Cathode end has a white line and positioned towards the left on the PCB. |
| D2, D4, D5 | SS310 | Required | Cathode end has a white line and positioned towards the top of the PCB. |
| D3 | SMAJ5A | Optional | Cathode end has a white line and positioned towards PCB right edge |
| D5 | PESD1CAN | Optional | None |
| F1 | Fuse | Required | None |
| J1, J2, J3, J4 | JST XH, or Terminal Connector | Required | None |
| J5 | USB-C Socket | Optional | None |
| LED1 - LED3 | Red, Green LED | Optional | Reference back of LED, cathode positions downward on the PCB. |
| R1, R2 | 47kΩ | Required | None |
| R3, R4, R7, R10 | 10kΩ | Required | None |
| R5, R6, R11, R12 | 1kΩ | Required | None |
| R9 | 2kΩ | Required | None |
| U1 | LM393 | Required | Small dot (pin 1) positioned to upper right corner |
| U2 | MCP73831 | Required | None |
| Q1 | BSS138 | Required | None |
| Q2 | IRLM6402 | Required | None |
Testing and Verification
The following test and verifications of the card should be performed after a through inspection of the card’s soldering. Check all of the PTH component pins and SMD pads. Make sure there are no solder bridges between pins and pads.
Visual Inspection
- Initial Check: Examine the board for any obvious issues like missing components, solder bridges, or components that are misaligned or not fully seated.
- Solder Joint Inspection: Use a magnifying glass or a microscope to inspect solder joints. Look for cold solder joints, insufficient or excessive solder, or any shorts between pads.
- Component Orientation: the IC’s are correctly oriented according to the PCB silkscreen or schematic.
Connectivity Testing
- Continuity Check: Use a multimeter in continuity mode to check for shorts between power rails and ground, and to ensure there are no open circuits in critical connections.
Power-Up Tests
-
Charge the batteries
- Connect a 5V USB-C charging cord to the Battery Card’s
CHARGE INUSB-C socket (J5) charging port and verify that USB Power LED is ON. - Insert the Battery Card into a powered Node Hub
If the batteries need charging, then the charging LED should also be ON with either of these power connections.
- Connect a 5V USB-C charging cord to the Battery Card’s
-
After the batteries are charged:
-
Disconnect all input power
-
Verify the output voltage at
BATT OUT(J4) is > 9V.BATT OUTprovides voltage only when there is NO input power to the Battery Card
-
Functional Testing
- Insert the Battery Card into a Node Bus Hub
- Verify that the Battery Card’s
LOW BATTLED is not ON. - Insert a Power-CAN Card into the same Node Bus Hub.
- Connect the Battery Card’s output plug into the Power-CAN Card’s
BATT INJST XH socket. - Insert an Quad-Node Card into same Node Bus Hub
- Disconnect the power to the Power-CAN Card
- Verify the Quad-Node Card’s ESP32 board’s power light is still ON, indicating that it is running (on battery power)
Troubleshooting
- See I2C Trouble Shooting.
Appendences
Specifications
| Characteristic | Value |
|---|---|
| Min Output Voltage | 9.0 V |
| Max Output Voltage | 12.6 V |
| Max Output Capacity | 1000mAh |
| Typical Output Voltage | 11.1 V |
| Max USB Input Voltage | 6V |
| Max USB Input Current | 1A |
| Recommended Charge Current | 500 mA |
| Charge Termination Voltage | 12.6 V |
| Discharge Cut-off Voltage | 9.0 V |
| Overcurrent Protection | Yes |
| Short Circuit Protection | Yes |
Notes:
- Max Output Voltage: This is the highest voltage provided by the fully charged 3S Li-Po battery.
- Max Output Capacity: This represents the battery capacity, which is 1000mAh.
- Max USB Input Voltage: The highest voltage that can be safely input through the USB for charging.
- Max USB Input Current: The maximum current allowed for charging the battery through the USB input.
- Min Output Voltage: The voltage at which the battery is considered fully discharged.
- Typical Output Voltage: The nominal voltage of the 3S battery pack.
- Operating Temperature Range: The range of temperatures in which the battery can safely operate.
- Storage Temperature Range: The recommended temperature range for storing the battery.
- Charge Termination Voltage: The voltage at which charging should be terminated to prevent overcharging.
- Discharge Cut-off Voltage: The voltage at which the device should stop discharging to prevent battery damage.
- Recommended Charge Current: The current recommended for charging to ensure battery longevity.
- Overcurrent Protection: Indicates whether the Battery Card has protection against excessive current.
- Short Circuit Protection: Indicates whether the Battery Card has protection against short circuits.
How It Works
flowchart LR
n["Node Card,<br/>Power-CAN Card"];
cc["Charging Circuit"];
b["Batteries"];
subgraph layout ["Train Layout"];
direction LR;
subgraph c ["Battery Card"];
direction LR;
cc --> |"5 V, 1A"| b;
b --> |"<12 V Detection"| cc;
end
b -->|"12 V<br/>(plug)"| n;
hub["Node Bus Hub"] -->|"5 V"| cc;
end
usb["USB Input"] -->|"5 V<br/>(plug)"| cc;
classDef lSalmonStyle fill:#FFA07A,stroke:#333,stroke-width:2px,font-size:24px;
class c lSalmonStyle;
classDef lightGrayStyle fill:#d3d3d3,stroke:#333,stroke-width:2px,font-size:24px;
class layout lightGrayStyle;
The Battery Card for the LCC Fusion Project integrates several key circuits to provide a stable, portable power source for LCC nodes:
-
Battery Configuration:
- Utilizes a 3S Li-Po battery pack, delivering a maximum output voltage of 12.6 V and a nominal voltage of 11.1 V. The voltage drops to 9.0 V when fully discharged.
-
Voltage Regulation:
- The output from the battery is regulated to provide a consistent 12 V supply.
-
Charging Circuit:
- Based on the MCP73831 IC, the charging circuit manages the Li-Po battery charging via USB. The charging current is set by an external resistor connected to the PROG pin, ensuring safe and efficient charging.
- Programming Resistor (Rprog): Sets the charge current. For example, a 2kΩ resistor sets the charge current to 500 mA.
-
Protection Features:
- Low Voltage Detection: Uses an LM393 comparator and a 9V Zener diode to monitor the battery voltage. When the voltage drops below 9V, the comparator triggers an alert to prevent deep discharge.
-
Low Voltage Detection Circuit:
- Voltage Divider: Scales down the battery voltage to a level suitable for the comparator input.
- Comparator (LM393): Compares the scaled voltage to a reference voltage (9 V) generated by a Zener diode. If the battery voltage falls below 9V, the comparator output changes state, indicating a low battery condition.
-
Integration with LCC Nodes:
The regulated output is connected via a JST plug directly to the Power-CAN Card, ensuring the LCC Fusion Node Cluster receives a stable 12 V supply. This allows the nodes to function reliably without reliance on fixed power sources, enhancing portability and flexibility.
When the Battery Card is installed in a Node Bus Hub, the batteries are automatically charged via the hub’s 5V connection. The batteries can be charged via a USB cable when the Battery Card is not installed in a LCC Fusion Node Bus Hub Hub.
Protection
| Protected Component | Protection Component | Function | Specifications | Location |
|---|---|---|---|---|
| Entire Battery Card | Polyfuses | Protects from sustained overcurrent conditions by increasing resistance when the current exceeds 1.5A and 3A. Resets once the fault condition is cleared. | Hold Current: 1.5A and 3.5A | In series with the incoming Power line |
| Entire Battery Card | SS310 Diodes | Protect against reverse voltage by blocking current flow in the wrong direction. | Hold Current: 1.5A and 3.5A | In series with the incoming Vcc line |
| Entire Audio Card | TVS Diode SMAJ5A | Protects from high-voltage transients by clamping voltage spikes, preventing them from reaching sensitive components. | Stand-off Voltage: 18 V Clamping Voltage: 29.2 V | Across the incoming Vcc and GND lines |
| Audio Amp | Decoupling Capacitors | Filters out high-frequency noise and transient voltage spikes from the power supply, ensuring stable voltage to audio amp IC. | Values: 0.1 µF ceramic, 10 µF electrolytic or ceramic | Across Vcc and GND near IC. |
| I2C Lines | Ferrite Bead BLM31PG121SN1L | Provides high-frequency noise suppression on the I2C lines. | Impedance: 120 ohms at 100 MHz | In series with the SDA and SCL lines of the I2C bus |
| I2C Lines | ESD Protection Diode PESD1CAN | Protects the I2C lines from electrostatic discharge and voltage spikes. | Reverse Stand-off Voltage (Vr): 24 V Clamping Voltage (Vc): 40 V | Across the SDA and SCL lines to GND |
| Power Connections | SS310 Diodes | Protect against reverse voltage by blocking current flow in the wrong direction. | Reverse Voltage: 100 V Forward Current: 3A | In series with battery and output connections. |
| Function | Part ID(s) | Purpose |
|---|---|---|
| High-voltage transient protection | D3 | Protects from high-voltage transients (>5 V) from hub and USB 5V inputs |
| I2C data bus ESD protection | D5 | Protects I2C data bus from electrostatic discharge (ESD) |
| USB-C Power input | J5 | 5V power input connector for charging battries |
| Low battery indicator | LED1, R6 | Indicates low battery status (<9.1 V) |
| Charging indicator | LED2, R11 | Indicates when charging is in progress |
| USB-C power indicator | LED3, R12 | Indicates power output via USB-C |