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

S-CAB Motherboard

2/22/2019

 

What is a Motherboard?

A motherboard is a circuit board onto which various sub-units ("modules") are mounted. Connectors and circuit traces on the motherboard facilitate modularity and eliminate wiring between modules.
Picture
MB-GP-v2: S-CAB installation motherboard
MB-GP-v2 fits a broad selection of HO scale, US style diesel-electric locos; EMD GP series, for example, often called "Geeps". It measures 0.67” wide, 5.75” long (17 x 146 mm), which is small enough for a GP-7 installation, yet large enough to accommodate a complete battery powered, radio controlled, ready-to-run system using commercially available DCC sound or non-sound decoders.
In addition to mounting BPS battery power supply, battery, radio receiver and decoder, the board ​includes terminals for external connections; track power pick-up, motor, LED lights and speaker. Depending on loco, lights and speaker can be mounted on the motherboard, which eliminates wiring connected to loco’s body shell and requires only 4 connections (power pick-up and motor) to loco chassis/frame. 

Assembly

​A 9-pin JST connector is provided for decoders with NMRA-compliant socket. No wiring harness is required. Decoders without a compliant JST socket require soldered connections and careful reference to decoder documentation. The BPS-v4 battery power supply can be mounted directly on motherboard (as in photo) or with a wired connection.
Picture
Add a decoder: This motherboard version requires either a SoundTraxx or NCE decoder with integrated S-CAB receiver. As shown in photo, no wiring is required for a SoundTraxx TSU-2200 decoder; just plug it in.
Picture
Plug in a battery: Depending on loco's space, 420, 800 or 1000 mAh batteries fit on the motherboard. If clearance between top of motor and roof interior permits, a 2P battery may be possible. However, 1P and 2P-420 are the only choices for HO scale, narrow-hooded GPs. The following photo includes a 1P-420 battery. Note the 3/4” battery leads, which will be default choice for batteries included with a motherboard installation.
Picture

Application

For HO models, application depends on the model’s prototype and its manufacturer. S-scale modelers should find the motherboard an easy fit. Fully assembled with a 1P-420 battery, the motherboard requires 0.44” (11.2 mm) headroom. Allow 12 mm (approx 0.5") clearance if using a 2P-420 battery. 
Models with limited headroom, motor mounted high on the chassis, for example, are not good candidates for this motherboard. Small yard switchers (SW series) in HO scale can also be eliminated as candidates. This still leaves a large selection of diesel prototypes for which this motherboard is applicable. However, creating unobstructed space can be a challenge. Factory installed circuit boards, over-sized metal castings, light-pipes, existing wiring and other clutter may have to be removed.

Example - Atlas-Kato GP-7 Installation

​This example used version 1 of the motherboard. ​No modification of loco chassis was required. The shell required some work. Light pipes were removed and interior of body shell decluttered. Lights and speaker were mounted on motherboard.
Picture
​The lens portion of light pipes was retained and glued into body shell.
Picture
Picture
​Components used:  TSU-1100 decoder, S-CAB radio receiver, 1P-420 battery, BPS battery power supply, mini-cube speaker, LED headlight and rear light.
Picture
Picture
Picture
Picture
Picture

NCE and SoundTraxx manufacture decoders referenced in this blog. Their proprietary rights, including product names, is acknowledged. 


Comments are closed.

    Author

    I'm a retired electrical engineer, but still spending more time on engineering than on my layout. These days, it's mostly about applying radio control and battery power on smaller scale layouts (HO, On3, On30)

    Categories

    All
    Historical
    Installation Notes
    Loco Projects
    Operation

    The photo above is not my layout. It's a great view of Seattle's King Street station by Ross Fotheringham.

    Archives

    February 2019
    October 2018
    September 2017
    August 2016
    April 2016
    January 2015
    November 2014
    May 2014
    April 2014
    February 2014
    November 2013
    October 2013
    September 2013
    August 2013
    July 2013
    June 2013

    S-CAB Conversions:
    S-scale NW2 Switcher
    On30 D&RG 4-4-0
    HO-scale GP9
    HO-scale GP35
    HO brass 4-8-4
    HO Bachmann 2-6-2

    S-scale EMD F-40PH
    HO-scale ALCO DL-109
    On30 Forney
    HO-scale Atlas-Kato GP-7


Proudly powered by Weebly