Radio Control and Battery Power for Model Railroads
  • Home
  • News
  • Battery Power
    • Batteries Explained
    • Battery Care
  • Radio Control
  • Price List
    • Contact Form
  • Quick Start
    • Getting Started
  • Documents
    • Hints, Comments, Notes
  • Neil's Blog

About this Website


Purpose

The purpose of this website is to encourage use of on-board battery power and radio control of locomotives (and similar traction equipment) modeled in HO, On3, and On30 scales. Combining on-board battery power and radio control has two major benefits:
  1. It eliminates the most inconvenient aspects of wiring track.
  2. It significantly improves reliability of model railroad operation by eliminating intermittent electrical contact between track and wheels.

What is S-CAB?

S-CAB is a set of components to implement battery powered, radio controlled HO-sized model trains. Two technologies are involved:
  • Battery power is fundamental for operating on unpowered track. Beyond this, S-CAB provides a unique capability of recharging batteries while a loco is stationary or moving on powered track.
  • Radio communication: S-CAB implements simple radio control that requires nothing more than the throttle transmitter and loco receiver. Turn on power, select loco, and run.​

S-CAB Radio

A hand-held wireless controller (the S-CAB throttle) communicates directly with a radio receiver installed in a loco. Commands transmitted by radio control a DCC decoder powered by an S-CAB onboard battery power supply.
Picture

S-CAB Power

BPS (latest version is BPS-v5), which is a core component of an S-CAB installation, provides 10 volts and up to 1.2  amps from a 3.7 volt battery. In addition to voltage conversion, BPS-v5 performs battery charging, safe battery management, battery on/off control, and overload protection; all within a small package.
Picture

Who may be interested

This website is for model railroad modelers and operators. I'm not an evangelist for new technologies or products. Quite the opposite; I'm an advocate for the simplest, most reliable, proven way to operate a model railroad.
S-CAB does not reinvent model train control. It builds upon, and is compatible with, existing model railroading products and standards, including NMRA standards for Digital Command Control (DCC). However, S-CAB is not DCC and does not require DCC equipment except for decoders, which are used for loco control.

Several obvious questions

Why use DCC decoders? ​

Because they're mature products with comprehensive model railroading functionality produced in vast quantities by many manufacturers. Development costs have long since been recovered and economies of scale give competitive advantage to established suppliers.

Communication to decoders is by radio?

Yes, for NCE and SoundTraxx decoders, the S-CAB receiver delivers DCC commands directly to the decoder's microprocessor. This is called "direct radio connect" (DRC) to distinguish it from the indirect method of using a DCC booster to convert radio data to DCC power.

What about other manufacturers' decoders?

Using a DCC booster is not as efficient as the direct radio connect, but works for most decoders.

Is a DCC system required?

No, a DCC system is not required. An S-CAB throttle transmits decoder commands directly to locos with S-CAB receivers. 

Is S-CAB compatible with DCC?

Yes, output from DCC command stations or throttles can be transmitted by S-CAB radio. It can also remain connected to track in order to operate locos without S-CAB radio. Where available, DCC track power can be used by S-CAB BPS for battery charging.

Can S-CAB be used with DC layouts?

The answer depends on equipment being used for DC control. If track power is used for BPS battery charging, a well-filtered DC supply between 12 and 13 volts is an ideal power source. Unfortunately, legacy DC voltage controllers often deliver unregulated output with voltage peaks (spikes) that can damage electronic equipment. BPS-v5 can survive voltage peaks up to 30 volts, but it's best to avoid use of old DC loco controllers, especially models with "features" such as "pulse power".

Getting started with S-CAB

A decision to use battery power is not easy. S-CAB components are available to fellow modelers but determining what will fit and operate successfully in a selected loco requires investigation of space within the model followed by installation and wiring of components.
​Getting started with S-CAB begins with an inquiry either by email or Contact Form.
Contact Form

What's happening in 2024?

August Update

By S-CAB standards, first 8 months of 2024 have been busy.
Eighty (80) BPS-v5 battery power supplies, sixty (60) decoders with S-CAB receivers, and over 100 batteries have been delivered. That's not bad for a hobby activity operating exclusively in a niche segment of model railroading without advertising or distributors. BPS-v5 has performed as hoped and is the core component of S-CAB systems. Decoders integrated with S-CAB radio receivers surprised with two thirds (40) of the total being non-sound and one third (20) sound. 
Picture
Motherboards
​The diesel loco motherboard for JST 9-pin decoders has simplified battery power installation in HO-scale, GP-type locos. The illustrated installation is unusual because clearance above motor allowed use of 2P battery instead of a 1P (single cell) battery. This loco operated at full speed on a test stand for 2 hours without battery recharge.

​An NEM motherboard has not been completed due to lack of interest.

Modularity
Installation difficulty discourages application of battery power. The purpose of modular design is to provide components that can be arranged conveniently in a variety of configurations to best utilize available space. The objective is to simplify installation and improve safety of battery power in small-scale models. Use of motherboards is one example; BPS-v5 design is another example, since it can be installed flat, as on the motherboard, with leads as in the generic version, or on edge within width of a typical HO steam tender.
Picture
​For use in steam loco tenders, BPS-v5 can be mounted on edge across rear of tender.
Picture

January Update

After difficult years 22 and 23, 2024 has started with great interest in S-CAB, particularly BPS-v5.
The good news:
  • There is high demand for BPS-v5 and its performance is proving to be excellent.
  • A new version of S-CAB throttle is now available. No change of functionality, but keypad uses tactile switches.
  • Inventory of S-CAB components is good. It takes additional effort, but each delivery is assembled and tested before shipping.
The not so good news:​
  • Price of latest deliveries of LiPo cells from China (the only affordable source for hobby use) has doubled.
  • Rigorous enforcement of regulations for transport of batteries seriously complicates shipment of goods that use LiPo batteries.
    Effective immediately, S-CAB international sales are no longer available, Canada is the only exception.
    US and Canadian shipment will use Fedex Ground. Minimum shipping cost for US is $18, for Canada it's $35.
BPS-Lite original version is discontinued and will be replaced by BPS-Lite-v5 using same components as BPS-v5.
  • It will use battery management half of the BPS-v5, and replace its voltage step-up half with a board for 3.7 volt power distribution.
  • How quickly this happens will demand on user interest.
Two versions of diesel loco motherboard are planned for BPS-v5.
  • A version for decoders with JST 9-pin connector is available.
  • A version for decoders using an NEM 21-pin connector is expected later this year.
420 mAh batteries are replaced by 1P-480 and 2P-480 batteries using a new supply of 480 mAh cells.
  • Dimensions are unchanged except cell thickness is 6.8 mm.
The S-CAB Order Form has been updated for 2024.
  • All quotes after January 21 will use the the new form.

What happened in 2023?

The big news: BPS battery power supply is now in stock.
Even better, it's a new version, taking advantage of newer components and improving a little on version 4 which it replaces. Nothing changes with respect to installation except its short enough (31 mm) to fit crosswise in most HO scale steam tenders.
BPS-Lite will be replaced by using battery management half of BPS-v5.
This is a benefit of BPS-v5 modular design which simplifies manufacturing.
All is well with S-CAB radio receivers.
They are integrated with NCE and SoundTraxx decoders using direct radio connect. A DCC version combines receiver with a DCC booster for use with factory-installed decoders, and the latest innovation adds dual control to Blunami decoders. S-CAB receivers can also be supplied with frequency that is compatible with CVP T-5000 and T-6000 throttles.
BPS-v5 User Guide

2021 Update

As I commented in a 2020 update, S-CAB components have iterated through several development cycles, reached a stable level of maturity and accumulated a solid base of user experience. They are a proven set of components for on-board battery power and radio control of HO On30, On3, and some S-scale models. 2020 was a busy year for development, which is now summarized under "News"
August 2021: This is a major website update. In addition to revising this "Home" page, a "News" tab has been added for quick access by visitors who are familiar with S-CAB. "Battery Power" and "Radio Control" tabs link to basic information for education/reference. "Price List" is most frequently visited S-CAB page. Some time will be required to implement changes, but the plan is to make "Price List" the go-to tab for S-CAB inquiries. Both Contact and Order Forms are moved under "Price List" tab. Future website maintenance will concentrate on "Home",  "News" and "Price List" pages plus occasional additions to "Neil's Blog". Blue tabs on the navigation diagram link to relatively stable information that does not require frequent updates.
Picture

S-CAB Components

On-board battery power and radio control are separate, compatible systems. For example, a loco can be controlled by radio while being powered from the track. This is not a particularly useful application of radio control because it fails to solve the basic problem of unreliable electrical contact between track and wheels. 
​If S-CAB is used for both on-board battery power and radio control, four components must be installed in the loco:
  • A battery power supply circuit board (current version is BPS-v5).
  • A one- or two-cell (3.7 volt) lithium polymer (LiPo) battery.
  • A radio receiver.
  • A DCC decoder. A speaker is required if using a sound decoder.
For steam locomotives, components are generally located in the tender. For diesel locos, the usual position is length-wise above the motor.
Component widths are designed to be less than 18 mm (0.7") to fit HO-scale GP-class diesel locos. When appropriate, these components can be mounted vertically on edge in steam loco tenders. Since a battery is generally the largest component, its position frequently constrains the overall installation plan.​
For suitable diesel locos, an S-CAB motherboard is the newest and easiest method of installation.
​

​BPS-v5 Battery Power Supply

Picture
​​S-CAB BPS combines a battery charger, battery management and a step-up voltage converter in one package.
It performs the following functions:
  • Battery protection: Overload, short-circuit, battery over- and under-voltage.
  • Battery switching: Automatic and manual on/off control.
  • Battery charging: From track pick-up or 2-pin connector.
  • Voltage conversion: Battery voltage stepped up to 10 volts.
The voltage of a lithium-polymer cell (LiPo), nominally 3.7 volts, is converted to 10 volts required for loco power. Where space is available, cells can be connected in parallel to increase storage capacity. A choice of battery sizes is available and all BPS batteries include a fuse for short-circuit protection. 

Batteries

Picture
Picture
Replaces the 1P-1000
Picture

​​S-CAB Loco Receiver

Picture
Picture
An S-CAB loco receiver is a radio module packaged with a DCC decoder such as the SoundTraxx sound decoder illustrated above. One unique characteristic of S-CAB is direct connection of radio receiver data to the decoder's microprocessor. This shrinks overall package size and avoids inefficiency of using a DCC booster to convert radio data to DCC power for input to decoder's left/right track connections.

S-CAB Throttle​

Picture
A nice photo by Peter Vanvliet of an older model S-CAB throttle
Picture
A wireless, battery-powered, hand-held controller completes the S-CAB system. Communication is direct from throttle radio transmitter to a compatible receiver in the loco to which a command is addressed. Each throttle can manage up to 15 locos during an operating session. The throttle's radio is only active while transmitting a command (approximately 0.04 seconds). Consequently, operating sessions with multiple participants and up to 6 active throttles is possible without noticeable interference.
​S-CAB Throttle v3
​The S-CAB throttle latest version (v3) uses a tactile button keypad instead of flexible membrane shown in previous version photo above.


Motherboards

​What is a Motherboard?

​​A motherboard (MB) is a circuit board onto which various components are mounted. Connectors and circuit traces on motherboard eliminate wiring between components. Terminals are provided for connections to loco motor, lights, speaker and battery charging input. In some cases lights and speaker can be mounted on the MB.
Picture
MB-GP-v2 in HO scale SD40

Example: Motherboard installation in a HO-scale Atlas-Kato GP-7

The entire assembly, including lights and speaker, is mounted on motherboard. No wiring bird-nest, no wired connections to the loco body and six connections to the chassis; two for motor and two from each truck for power pickup.
Picture

Acknowledgements

References to various manufacturers and their products are scattered throughout this website. Their proprietary rights, trade marks, copyrights, etc. are acknowledged.
Proudly powered by Weebly