Node Power Planning Guide
Table of contents
Table of contents
Introduction
When setting up your LCC Fusion Node Cluster(s) for model railroad automation, a crucial consideration is the choice of power supply configuration. Efficient power management ensures stable operations, longevity of the components, and safety. It is essential to understand the power requirements of each component within the cluster to ensure that your chosen power supply can adequately support the entire system without risk of overload or insufficient power delivery.
Below are options for powering the LCC Fusion Node Cluster using one or more power supplies and various connection option. Select a method that works best based on planned usage.
Note: This document specifically addresses DC power supply configurations, as the LCC Fusion Node Cluster is designed to operate exclusively with DC power supplies. AC power configurations are not supported and are not covered here.
General Safety Recommendations:
- Always select a DC power supply rated above your calculated maximum load to ensure safety margins.
- Include fuses or circuit breakers appropriate for your setup to protect against shorts and overloads.
- Regularly inspect wiring for signs of damage or overheating.
Common Ground
A Common Ground is the shared 0 VDC reference that ties together all logic, power, and devices in an LCC Fusion system. Without a common ground, signals between cards and breakout boards cannot be interpreted reliably, and current may return through unsafe or undefined paths.
How a Common Ground is Created
- The Node Card and CAN-Power Card establish the primary ground plane for the system.
- This ground is automatically distributed to all other cards through the Node Bus Hub.
- Breakout boards may connect to this same ground using the card’s LINE 8 selector, which can be set to GND when a return path is needed.
Options for Connecting to the Common Ground
- Line 8 GND (Card → Breakout)
- Required when the breakout board has no other valid ground reference.
- Optional when the breakout board is powered from a DC accessory bus that already shares the same supply as the Node Card.
- Layout DC Bus
- If the layout’s DC accessory bus also powers the Node Card, its negative rail (DC−) is already common and can be used directly by breakouts.
- If the Node Card and layout bus are powered by different DC supplies, their DC− outputs must be bonded together so they share the same reference.
- AC or DCC Bus
- After rectification, the resulting DC− is floating until it is tied to the Node’s GND.
- In these cases, Line 8 must be configured as GND to provide a common return path.
Rule of Thumb
All signals and devices must share one common ground for reliable operation. Tie all DC− rails to the Node’s ground plane at a single point, and never attempt to bond power supplies at the AC input side.
LCC Node Cluster Power Consumption Guide
Power consumption can often be misunderstood when looking at individual component current ratings. At first glance, it may seem like an ESP32 drawing 200 mA could quickly consume available power in a 3A system. However, real-world power distribution accounts for voltage levels, regulator efficiency, and actual current needs at different supply voltages.
Higher input voltages reduce current draw at the source while allowing efficient conversion to lower voltages using switching regulators. This means that a 65W power supply is more than sufficient to support an LCC Node Cluster with multiple I/O cards, breakout boards, and ESP32-based components.
This guide provides realistic power consumption estimates to help users select an appropriate DC power supply based on actual energy needs, rather than just summing up component current ratings.
| LCC Fusion Cards/Boards | 12 VDC Load (mA) | 5 VDC Load (mA) | 3.3 VDC Load (mA) | Power (W) | 16 VDC Input (mA) | 24 VDC Input (mA) | 35 VDC Input (mA) | Notes |
|---|---|---|---|---|---|---|---|---|
| LCC Node Card (no I/O, WiFi, or Bluetooth) | 5 | 80 | 2 | 0.48W | 30 | 20 | 14 | 80 mA for ESP32 and manages Node Bus communication without Bluetooth and WiFi enabled. 7mA for idle regulators. |
| BOD Card (1 detection) | 0 | 0 | 20 | 0.16W | 10 | 7 | 5 | 27 mA for IC + 3mA for 1 LED on. |
| PWM Card (16 lamps @ 15%) | 0 | 16×3 | 0 | 0.32W | 20 | 13 | 9 | 3mA per LED. |
| Turnout Card (1 Tortoise) | 20+20 | 0 | 1 | 0.48W | 46 | 32 | 22 | 21 mA for Turnout Card components + 20 mA Tortoise |
| Output Card (8 LEDs @ 15%) | 0 | 8×3 | 0 | 0.16W | 10 | 7 | 5 | 7mA for ICs, 3mA per LED at 15% brightness with 1K resistor. |
Network Power Considerations
The estimated power consumption for a basic signaling configuration (Node Card with 5 I/O cards and breakout boards) is only ~2.6W as shown below. This is significantly lower than the typical computer laptop 65W power supply capacity, indicating plenty of available power for expansion.
Additionally, the maximum current capacity of the Node Card power traces and regulators is 3A, which is well above the estimated current draw in typical configurations. This means that a single LCC Node Cluster can support a large number of hardware devices within the network without exceeding power limitations.
| Use Case | Card / Breakout Board | Power Supply @ 24 VDC (mA) |
|---|---|---|
| Detection, turnout, signaling for track spur | 1x LCC Node Card 1x BOD Card /w 4 detections 1x PWM Card /w 16x LEDs on 1x Turnout Card /w 1x Tortoise |
20 07 13 32 Total 72 mA (1.7W) |
| Detection, turnouts, signaling for track siding | 1x LCC Node Card 2x BOD Card /w 8 detections 2x PWM Card ea/w 16x LEDs 1x Turnout Card /w 2x Tortoise |
20 14 26 48 Total 108 mA (2.6W) |
Power Sources for LCC Fusion Components
| Component/Board | Power Supply (DC) | Node Bus Hub (DC) | Layout Power Bus (AC/DC/DCC | Notes | Ground Reference Requirements |
|---|---|---|---|---|---|
| LCC Node Card | ✅ | ❌ | ❌ | Main processing and network hub. | Provides the system ground plane. |
| All I/O cards | ❌ | ✅ | ❌ | Automatically share ground via Node Bus Hub. | |
| Block Breakout Board BLVD Breakout Board BRD Breakout Board |
❌ | ❌ | DCC | Routes Track Bus and Track Rails to attached card. | N/A – Wiring-only breakout board. Ground not used. |
| DC Motor Driver Breakout Board | ❌ | ❌ | AC DC DCC |
Layout Power Bus AC, DC, and DCC supported via bridge rectifier | Either: 1) Line 8 of PWM Card configured for GND 2) DC Layout Power bus shared with the Node Card’s power supply. |
| Digital I/O Breakout Board | ❌ | ✅ | AC DC DCC 5V |
Layout Power Bus AC, DC, and DCC supported via bridge rectifier.«br/>5V from Node Card I/O, Digital I/O Card, or Output Card (requires LINE 8 configuration) | Either: 1) Line 8 of PWM Card configured for GND 2) DC Layout Power bus shared with the Node Card’s power supply. |
| Digital Sensor Breakout Board | ❌ | ✅ | ❌ | Uses Node Card (or Sensor Card) 5V/GND, converted to 3V3 and 5V for sensors (requires LINES 7/8 configuration for 5V/GND) | Line 8 of Sensor Card is used. No configuration required. |
| NeoPixel Breakout Board | ❌ | ✅ | AC DC DCC |
Layout Power Bus AC, DC, and DCC supported via bridge rectifier.«br/>5V from Node Card I/O or PWM Card (requires LINE 8 configuration for GND) | Either: 1) Line 8 of PWM Card configured for GND 2) DC Layout Power bus shared with the Node Card’s power supply. |
| Node Analog Sensor Breakout Board | ❌ | ✅ | ❌ | Uses Node Card 5V/GND, converted to 3V3 for 3-wire sensors. | Always uses Node GND via Line 8 (required). |
| NFC Tag Reader Breakout Board | ❌ | ✅ | ❌ | Always uses Node GND via Line 8 (required). | |
| POD Breakout Board | ❌ | ✅ | ❌ | Comparator outputs must be tied to Node GND. | |
| Relay Breakout Board | ❌ | ✅ | AC DC DCC 5V |
Layout Power Bus AC, DC, and DCC supported via bridge rectifier. 5V from attached card (requires LINE 8 configuration for GND) |
Either: 1) Line 8 of Node Card I/O, Digital I/O Card, or Output Card configured for GND 2) DC Layout Power bus shared with the Node Card’s power supply. |
| Servo Motor Breakout Board | ❌ | ✅ | AC DC DCC |
Uses either: Layout Power Bus (AC, DC, and DCC) supported via bridge rectifier. 12V from PWM Card (requires LINES 7/8 configuration for 12V/GND) |
Either: 1) Line 8 of PWM Card configured for GND 2) DC Layout Power bus shared with the Node Card’s power supply. |
| Signal Masts Breakout Board | ❌ | ✅ | AC DC DCC |
Uses either: Layout Power Bus (AC, DC, and DCC) supported via bridge rectifier. 5V/12V from PWM Card (requires LINES 7/8, 15/16 configuration for VDC+/GND) |
Either: 1) Lines 8/16 of PWM Card configured for GND 2) DC Layout Power bus shared with the Node Card’s power supply. |
| Stepper Motor Breakout Board | ❌ | ❌ | AC DC DCC |
AC, DC, and DCC supported via bridge rectifier. | Motor supply DC− must be bonded to Node GND for control signals. |
| Test Breakout Board | ❌ | ❌ | AC DC DCC |
AC, DC, and DCC supported via bridge rectifier. | Rectifier DC− must be tied to Node GND. |
| Turnout - Twin-Coils Switch Machine Breakout Board | ❌ | ❌ | AC DC DCC |
AC, DC, and DCC supported via bridge rectifier. | Coil supply DC− must be tied to Node GND. |
| Turnout - Servo Switch Machine Breakout Board | ❌ | ❌ | AC DC DCC |
AC, DC, and DCC supported via bridge rectifier. | Servo supply DC− must be tied to Node GND. |
| UOD Breakout Board | ❌ | ✅ | ❌ | Comparator outputs must be tied to Node GND. |
| Component/Board | Power Supply (DC) | Node Bus Hub (DC) | ACC BUS (DC) | Track Bus (DCC) | ACC BUS (AC) | Notes |
|---|---|---|---|---|---|---|
| LCC Node Card | ✅ | ❌ | ❌ | ❌ | ❌ | Main processing and network hub. |
| All I/O cards | ❌ | ✅ | ❌ | ❌ | ❌ | |
| Audio Breakout Board | ❌ | ✅ | ❌ | ❌ | ❌ | |
| Block Breakout Board | ❌ | ❌ | ❌ | ✅ | ❌ | |
| DC Motor Driver Breakout Board | ❌ | ❌ | ✅ | ✅ | ✅ | Required 5V or 12 VDC from a power bus. AC, DC, and DCC supported via bridge rectifier. |
| Digital I/O Breakout Board | ❌ | ✅ | ✅ | ✅ | ✅ | AC, DC, and DCC supported via bridge rectifier, or 5V via attached card (lines 7/8) |
| Digital Sensor Breakout Board | ❌ | ✅ | ❌ | ❌ | ❌ | Uses Node Card (or Sensor Card) 5V/GND, converted to 3V3 and 5V for sensors. |
| NeoPixel Breakout Board | ❌ | ❌ | ✅ | ✅ | ✅ | AC, DC, and DCC supported via bridge rectifier. |
| Node Analog Sensor Breakout Board | ❌ | ✅ | ❌ | ❌ | ❌ | Uses Node Card 5V/GND, converted to 3V3 for 3-wire sensors. |
| NFC Tag Reader Breakout Board | ❌ | ✅ | ❌ | ❌ | ❌ | |
| POD Breakout Board | ❌ | ✅ | ❌ | ❌ | ❌ | |
| Relay Breakout Board | ❌ | ✅ | ✅ | ✅ | ✅ | AC, DC, and DCC supported via bridge rectifier, or 5V via attached card (lines 7/8) |
| Servo Motor Breakout Board | ❌ | ✅ | ✅ | ✅ | ✅ | AC, DC, and DCC supported via bridge rectifier. 12 VDC from Node Bus Hub via PWM Card |
| Signal Masts Breakout Board | ❌ | ✅ | ✅ | ❌ | ❌ | Use of ACC BUS is optional |
| Stepper Motor Breakout Board | ❌ | ❌ | ✅ | ✅ | ✅ | AC, DC, and DCC supported via bridge rectifier. |
| Test Breakout Board | ❌ | ❌ | ✅ | ✅ | ✅ | AC, DC, and DCC supported via bridge rectifier. |
| Turnout - Twin-Coils Switch Machine Breakout Board | ❌ | ❌ | ✅ | ✅ | ✅ | AC, DC, and DCC supported via bridge rectifier. |
| Turnout - Servo Switch Machine Breakout Board | ❌ | ❌ | ✅ | ✅ | ✅ | AC, DC, and DCC supported via bridge rectifier. |
| UOD Breakout Board | ❌ | ✅ | ❌ | ❌ | ❌ |
Note: While the Node Card itself usually receives its power from the accessory bus (if not from a dedicated power supply), many breakout boards will also draw some current from the same accessory bus. In several cases this is not just for the board’s logic, but also to power attached I/O devices such as LEDs, relays, servos, or motors. When planning total accessory bus capacity, be sure to account for both the Node Cards and the cumulative loads from all connected breakout boards.
Power Supply Options for LCC Node Clusters
There are two main approaches to powering your LCC Node I/O cards and the attached LEDs, each with its benefits and considerations.
Option 1: Single Power Supply Configuration
The simplest method is to employ a single power supply to power both the LCC Fusion Node Cluster(s) and the layout accessories. In this configuration, all LCC Fusion Project components, including layout accessories like LEDs attached to the I/O cards, share a common ground. This approach minimizes complexity and reduces the number of components required. It’s ideal for setups where all of the power requirements of the layout accessories and the LCC Fusion Node Cluster are within the capacity of a single power supply, ensuring a streamlined and efficient power management system.
Advantages of the single power supply configuration include:
- Simplicity: Easier setup with fewer components to manage.
- Cost-Effectiveness: Reduces the need for multiple power supplies, saving on costs.
- Unified Grounding: With a shared common ground, there’s a reduced risk of ground loop issues, which can be crucial in sensitive electronic environments.
Option 2: Dual Power Supply Configuration
For more extensive setups or where the power demands exceed the capacity of a single supply, a dual power supply configuration can be used. In this scenario, one power supply is dedicated to the LCC Fusion Node Cluster and its I/O cards, while a second, separate power supply is responsible for providing power to layout accessory devices (i.e. LEDs, etc.). Importantly, these devices will ground through a layout accessory bus’s common ground back to the second power supply. Despite using two power sources, both power supplies share the same ground—this can be achieved through a common power strip or connected to the layout room ground to ensure stability and prevent potential electrical interference.
The dual power supply configuration offers several benefits:
- Flexibility: Allows for greater power distribution thru segmentation, especially useful in larger or more power-intensive setups.
- Stability: By dividing the power load, each supply can operate within its optimal capacity, potentially increasing the lifespan of the components.
- Safety: Separating the power sources can enhance safety, as it allows for more controlled management of power flows and reduces the chances of overloading a single supply.
In summary, the choice between a single or dual power supply configuration depends on your specific needs, including the scale of your LCC Fusion Node Cluster, power requirements, and considerations for cost, complexity, and safety. It’s essential to carefully plan your power supply strategy to ensure a stable and efficient operation of your model railroad automation system.
Use Cases
The LCC Fusion Project provides several methods of power a LCC Fusion Node Cluster, a single LCC Card, or just I/O cards. This can be useful while testing new hardware, configuring an LCC Node, or for distributing multiple LCC Node Clusters or I/O cards around an under your layout. These options can be use for both convience and simplifying layout wiring while providing optins for integration with a layout power grid.
Below is a table summarizing the use cases for each type of power input connector available with the LCC Fusion Project hardware. This table is designed to help planners choose the most appropriate connector based on their requirements, including the number of secondary LCC Nodes, LCC Node Clusters, LCC Node Bus Hub(s), and I/O cards to connect and their preferred power sources.
Refer to Terminology for an explanation of terms used below
| Connector Location | Power Input Connector | Power Module | Max Current / Voltage | Use Cases | Why Choose This? | Considerations |
|---|---|---|---|---|---|---|
| DevKit-C Module on LCC Fusion Node Card | USB Connector | No | 2A / 5V | Use while testing a LCC Fusion Node Cluster and using the computer’s serial monitor. | LCC Node has an integrated management system for bench testing hardware. Don’t use for non-testing to prevent damage to the DevKit-C Module circuitry. | Use computer based serial monitors such as Arduino IDE, PuTTY, RealTerm,Tera Term, CoolTerm, and YAT. |
| LCC Node Bus Hub | USB-C Connector | No | 3A / 5V | Use while testing or temporarily powering a small LCC Fusion Node Cluster. | Simplifies adding power from any location using a USB cable. When using a LCC Fusion Node Card, consider using a Power Module for more robust power supply and protection. | Use temporarily when 12 VDC+ is not required and working with a small LCC configuration. Computer power adapters can provide up to 3A with a USB-C plug. |
| LCC Node Bus Hub | 1) Network Cable Sockets (RJ45) 2) 8-Pin Female Pin Headers |
No | 600 mA / 3V3, 5V, 12 VDC+ | Use when expanding the LCC LCC Fusion Node Bus with additional LCC Node Bus Hubs without a Primary LCC Fusion Node Card. | Required for expansion (secondary) LCC Node Bus Hub to receive power and communications from another LCC Node Bus Hub. Useful when powering additional Node Bus Hubs with centralized locations around the layout. |
Use CAT6 network cable to carry more current. Secondary Node Bus Hub can be daisy chained together. |
| LCC Fusion Node Card | CAN Bus Network Cable Sockets (RJ45) | Yes | 600 mA / 12-35 VDC | Smaller networks with a focus on simplicity and integration of power and communication in one cable. Ideal for scenarios where the layout is compact or the number of secondary LCC Nodes is limited. | Simplifies cabling by integrating power and communications. Less clutter and easier to manage in smaller setups. | Limited to 3-5 secondary LCC Nodes. Requires network cable between LCC Nodes. |
| Power-CAN Card | USB-C or DC-005 (barrel connector) | Yes | 2A / 12-35 VDC | Medium-sized networks requiring more secondary LCC Nodes. Suitable for users with readily available USB-C power supplies (e.g., laptop chargers). Good balance between power capacity and convenience. |
Easy connect/disconnect of power. Utilizes common, modern power supplies. Offers a good mix of power capacity and ease of use. |
Suitable for a moderate number of secondary LCC Nodes. |
| Power CAN-Card | Spring/Screw Terminal, or ATX 5557 Connector | Yes | 3A / 12-35 VDC | Larger networks with a higher number of secondary LCC Nodes. Ideal for users who prefer to use their layout accessory power supply, providing the highest power capacity. | Maximizes the number of secondary LCC Nodes that can be connected. Best for extensive layouts requiring significant power distribution. | Leverages existing layout accessory power supply. Supports max number of LCC Nodes. LCC Fusion Node Cluster can be serially connected using both input and output ATX connectors. |
This table offers a straightforward comparison to help planners make informed decisions based on their specific needs and preferences for their model railroad automation projects. Each connector option caters to different scales and complexities of layout setups, ensuring flexibility and adaptability in planning and implementation.