3 Aug 2012

Fiddle Yard Construction

I have spent much of the last few months making slow but steady progress - I have built four of the control boards I need - including the power distribution board which contains 2 x PM42 power distribution thingys from Digitrax. This allows the network to be separated into a number of separate power feeds - on a large layout like this it also helps short circuit detection in that you can immediately see which area of the network you have a short on. Finally it does the job of inverting the polarity for the reversing loop. The power distribution board also distributes three other AC and DC supplies for powering various things - You can see it propped up on top of the basebaord on the left of this picture...

some placeholder words for the tool tip

It does seem though that I have enough power feeds to supply a good section of the london underground!

I have also installed under the reversing loop slope section an infra-red detector to automatically change the reversing loop point whenever a train is approaching it. This works well apart from the fact that it doesn't always initialise to the correct orientation - I have not investigated cause or solutions to that yet.

Hopefully I can now lay the track for the fiddle yard quickly as I have built the control boards to supply all of the points - 14 or so and all of the detection sections 28 or so.

One of the reasons for my lack of updates on this blog is the update to Mac OS X 7 - my own blog writing software (written in objective-c) used older Operating Sytem calls no longer supported in OSX 7.x so I had to open up the software and fix it - a trivial job in itself but downloading the latest development environment on my slow link and educating my slow brain in the changes to the OS API was a big obstacle!

some placeholder words for the tool tip
click here to return to the blog