Sunday, November 13, 2016

A Light Bulb Moment

Although the title of this post would suggest that I have come up with a rather bright idea, sadly it’s not the case, but I am a sucker for a catchy title and a good pun, and there is some light bulb content to come, so the title is relevant none the less.

To start with the most recent blogworthy event, after being involved with the Central Coast Wednesday Night model railway group for coming up to twelve months now, who generally meet each Wednesday night at a members house, it was nice to finally be able to host a meeting last Wednesday afternoon. Due to various circumstances including renovations, the train room has been somewhat less than ideal for hosting a meeting, but as of a couple of weeks ago everything that was in there that didn’t belong in there was removed, leaving it not only more spacious, but giving an uninterrupted 360° view of the layout.

Being part of a group with a common interest is always enjoyable, and attending quite a few meetings at different members houses and getting to see their layouts has been a great source of inspiration and a lot of fun. So for me it was good to be able to contribute and give something back to the group, and to have the guys around to not only see, but to give feedback on what has been done so far. It was a most enjoyable afternoon, with lots of train related chat, and thanks to my wife a lovely afternoon tea spread with lots of yummy food, overall a very pleasant way to spend a Wednesday afternoon.

The afternoon also included a bit of a win, in regards to getting my Mac laptop to talk to my NCE Power Pro DCC system. I have only in the last week or so managed to get the Power Pro, laptop and Wi-Fi modem mounted where they belong, so that I could begin using the JMRI software which includes Decoder Pro, as well as being able to run WiThrottle which allows for wireless operation using an iPhone/iPad.

The Power Pro has a serial input, so I purchased a serial to USB cable as suggested, but no matter what combination of settings we used we could not get a connection happening. In the end we used the NCE USB adapter that I had previously used with my Power Cab that was connected to a small test track which was operating successfully with WiThrottle. Ultimately this is not the way to go as it is said that using this USB adapter will not allow a lot of the Decoder Pro functions to work properly, but for the meantime at least it allows for wireless operation.

After doing a bit of research, it might be that I need to download a specific driver for the serial cable, information on thiss stuff is always a bit fuzzy, but I will give it a shot and see what happens.

As well as getting this connection working, the wireless transmitter for the Power Pro system was mounted above the layout and connected up, so once I put some AAA batteries in the Pro Cab and Power Cab hand throttles they will also now work wirelessly. I had the old Power Cab hand throttle converted to a radio throttle by the Model Railway Craftsman at Blacktown.

Going back a week or so, my Dad came for a visit for a bit over a week, so we spent a bit of time in the train room with the soldering iron cranked up. As part of one of the previous build sessions, the main heavy DCC bus wiring was already run around both levels of the layout, consisting of pre-twisted red and black 11 gauge AWG wire, purchased from DCC Concepts in Perth, Western Australia.

I spent quite a bit of time researching what wire sizes were required for reliable operation, and not surprisingly opinions varied quite a bit, but in the end it seemed to me that it is possible to go too small, but not to go too big within reason and common sense (i.e. car battery cable probably IS too big!).

The main bus on the top and bottom decks are around nineteen metres each in length, and the top and bottom decks of the layout are each made up of eight modules, each of which will have its own power supplied from the main bus.

I have chosen to use the light bulb method to both indicate when there is a short circuit, and to stop the whole system shutting down if a short circuit occurs. To do this I have used the 1156 style automotive bulb, the ones I ordered were 21 Watt from memory, and I ordered some in clear white, orange and red, and will experiment to see which ones look the best when lit up, so far the orange has the nod.

To mount the globes I searched around until I found what I thought were the most suitable bulb holders, these look to have the most substantial wiring coming off them, and it should be relatively simple to mount on the layout. I haven’t decided exactly how or where the light are bulbs will be mounted, but there is enough length in the wiring where they joined to the main bus that I will not be restricted in where I can place them.

The wiring from the bulb holder is soldered to the main bus wiring, and on the other end is a pluggable terminal strip, which I also purchased from DCC Concepts.

Having a pluggable terminal from the main bus feed makes it very easy to supply power to each module, that is quick and easy to disconnect and connect when required. It also means that in the meantime I can use these power feeds from the main bus to test by simply attaching wires into the plug.

The beauty of having each module individually powered and protected by the light bulb is that if a short occurs only that module will shut down, and the rest of the layout will not be affected.

I am also considering mounting a simple on off switch in line with the light bulb so that if a short does occur, power to that module can be turned off while the short is investigated, as although the light bulb visually warns of a short it does not remove it, so a secondary system of cutting power to each individual module is a good idea.

Going back a little bit further (this post is all going in reverse for some reason!), I always had it planned that the DCC system, power supply for the point motors, and the laptop would all be mounted in the same area, so when the cabinet work was built around the room, a space was left at the rear under the bench top for a suitable set of shelves and drawers.

The guy who did all of the cabinet work was able to build an insert that is divided left and right, which features a sliding shelf at the top on each side, and a sliding drawer underneath on each side, and then open space below.

Getting everything neatly organised in its place is still a work in progress, but for now the laptop and Wi-Fi modem/router are sitting on the top left sliding shelf, and on the top right sliding shelf is a power board, with the DCC system and the power supply for the point motors.

This allows the laptop to be slid out when it is needed and stored away neatly when not in use, the power board makes it easy to switch everything on from one spot, and the DCC system and points power supply are easily accessible by sliding the shelf out, but again neatly out of the way for normal operation.

I think for now that is probably enough information for this post, so until next time it is bye for now.