The Jawbone Branch construction is now proceeding into the electrical installation phase. Two weeks ago in the last blog post (Jawbone Branch Part 29), I covered some of the LED lighting testing with new 12VDC power supply. The last two weeks have been spent mostly waiting for parts and tools to arrive before I could do any more meaningful work.
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| Molex meets the Jawbone |
I learned about Molex electrical connection for the last 20-25 years I've worked on the LMRC layout in San Diego. The system is reliable and fairly simple to use. Multiple connector housings allow for mixing and matching the number of conductors to the application's requirements.
Electrical Connectors
When I worked out the Jawbone Branch track and bench work plan, I expected to use Molex Connector system with 18 AWG bus wires under each module. The track module connections will have 14V DCC (+/-) and I was also figuring at least 12VDC fixed if I wanted to do lighting in any of the buildings at Bartlett and Little Lake. The Owenyo modules will also need to have Mojave Staging LED lighting connections as well, totaling at least 6-conductors. So I ordered mostly 6-pin plug housings and a few 9-pin plugs, and a pile of miscellaneous 2-pin plugs to use where ever needed.
Tools Required
Molex Pin Extraction Tool
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| Just in case I need to remove a pin or two, the Molex Extraction Tool is needed. |
11-03-0006 $22.48 @ Molex website
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| Internals of Molex extraction tool. |
The extraction tool uses a tube to align with the hole and retract the barbs in the pins within the housing and then a blunt internal push-rod to push out the pin.
Housings & Pins
Ordered from Digikey or other online vendor.
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| 9-Pin Connection Receptical (left) and Plug (right) and examples of female and male 0.093" pins. |
Mojave Staging Electrical Plan
Mojave Modules will have their own 6-conductor plugs, which will connect the 5 DCC (North Rail) control wires to the yard tracks and one common DCC (South Rail) along the length of the yard. This will allow whole yard tracks to be turned on and off from a single panel at the east end of the yard (next to the Owenyo Wye). The lighting for the staging yard will be part of the Owenyo modules and wiring above, so no need to have under Mojave module lighting, unless I want to run LED lighting for the workbench, which may either be LED bar lights or extra LED strips from the layout lighting, again, 2-pin plugs will do for any of that needed.
Feeder Wires
The next major step on the modules with track on them is drilling and installing the feeder wires. Each rail section will have a 22 AWG feeder wire soldered to the rail, connecting to the 18 AWG bus DCC wires underneath.
The wires are color coded black (North Rail) and white (South Rail). The bus wires are color coded black (North) and red (South). I don't want to have any confusion, the white wire in the layout will be the common (-) for the LED lighting, which will also be running along the same connectors as the DCC power.
Bus Wires
I was able to get a good price on 18 AWG multi-strand wire from Grainger in Sparks, NV. So bought several colors in 100ft rolls. Should be enough to do the bus wiring for a mainline run of only about 60-80ft max. I also picked up some wire that would be used for the LED lighting and common 12VDC negative return in 12 AWG to handle the extra current.
The LED lighting bus wires will be held by cable clamps on the non-layout side of the plywood strips which are cut at the desired angle for the LEDs to point at the layout. Each strip of plywood LED section will have jumper off of the main bus to keep the power going down the LED strips to a minimum.
The LED lighting bus wires will be held by cable clamps on the non-layout side of the plywood strips which are cut at the desired angle for the LEDs to point at the layout. Each strip of plywood LED section will have jumper off of the main bus to keep the power going down the LED strips to a minimum.
LED Lighting Connectors
Molex connectors are also used for connecting ceiling LED lighting strips with 12VDC Common ground and 12V constant, and variable 12VDC running each of the 4500K and 6000K LED strips. The 2021 vintage LED strips I test installed were rigged as one-piece.
The LED lighting strips will now be split into shorter sections with plugs between each as it works around the room.
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| New 18 AWG wire feeders for each section of LED Light Strip. |
I fabricated short 18 AWG feeders with the Molex Pins. Then insert them into the Molex 2-pin connector housings. I want to keep the wire coloring simple out in the field, as around Mojave Yard and under Owenyo there will be Track DCC, structure lighting, and two variable LED color lighting wiring. I've decided that Blue will be the control wire for the 6000K (bluish) LED lighting positive and Yellow will be used for the 4500K (yellowish) LED lighting positive power. Heavier 12 AWG common white will be used for the LED negative wire. I'll be fabricating some smaller 18 AWG white for the feeders from the bus to the main cable.
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| Blue (6000K LED) Plugs being pre-fabbed for installation. |
Lighting Bus wires will need feeders for each section with a plug to allow easy setup of the strips. These feeders harnesses are being fabricated on my bench instead of over-head in place. It is much easier this way!
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| Blue (6000K) and Yellow (4500K) LED Plugs finished, waiting for common white wire feed. |
This should make working on any section easier in general. Such as while I need to bond the LED strips to the plywood strips. (I believe it was this temporary overhead work that injured my shoulder last year, or at least pushed it over the edge.)
Rewiring 12VDC Lighting Power Supply
After doing the testing of the new 12VDC power supply in the last post, I'm rewiring it to have staggered 120V AC splice joint with double heat shink tubing over the joint. I had only clip-leaded the LED light strips for the power supply testing. The rewiring will allow the installation of permanent Molex connectors. I also plan to drop the LED strips and the plywood strips down from the ceiling and break them into shorter sections with plugs between them.
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| 2-Pin Plug for 12VDC Power Supply |
I've decided to use a 2-pin plug for the power supply-to-dimmer switch wires. This will make it easy to remove or swap power supplies.
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| 12VDC +/- coming from right (black & white) splitting to the left to the dimmers and blue and yellow from dimmer module, in process. |
There will be a section of large 12 AWG wire in a harness splitting the 12VDC +/- connecting to a 6-pin housing which also gathers the 3 conductors (Blue, Yellow and Common White) from the ceiling LED wire bus legs.
The power supply and controls are going to feed into the middle of the lighting bus for the ceiling. I'll probably have a 'pig tail' plug come off on the way to ceiling to join the underside of Owenyo #3 Module (not built yet) which will join the Mojave Staging lighting LED strips to the LED system. I'll probably have a on-off switch for the Mojave Staging lighting under the Owenyo #3 module.
In Closing
The electrical front of the Jawbone Branch will now be in the forefront of the effort. Getting the lighting set up and then setting up the track wiring really needs to be done before any new layout modules are constructed.
Jason Hill
Jawbone Branch (Part 29) - New Lighting Power
Jawbone Branch (Part 24) - Let There Be Light
