Detection Circuit WORKS!

Thanks to John from railpage.com.au, I build the circuit which detects the passing of a train turning the signal to red using a current sensing architecture! From what turned out as a dream, I cannot believe this is now reality!!

Here is a small video:

Grade gone

I built it and it took me 1 week and its gone in 5 mins....

Somehow it didn't do it for me - layout seemed more toy like - maybe because it felt like a yo-yo - up then immediately down mmm... oh well at least I gave it ago and will reconsider my options - I really want to add a trestle bridge in that area so will most likely build a small L girder benchwork or something.

Building the Grade

I decided to build an incline because my layout seemed too flat! So, using some basic calculations I build a 2% or 1 in 50 grade (to calculate this you divide 1 by 50 then multiply for 100 to give you 2%)

I see that the maximum grade or most frequently used maximum grade used by VR was a 1 in 50 so I thought this should be my maximum on the layout.

Here are some photos for the building phase.

Track Plan

Some Changes
Create another 'branch' line from Ingle to staging. I thought part of 'operation' is also controlling signals and points - so this branch line adds another dimension to the layout - also it gives at least one more operational move. Only draw back is that this branch line is a 'dead-end' where the 0-5-0 will have to play its part to move the loco the other way round -
Another draw back is that the the radius of the curve of the main track to staging had to be reduced to 20inches - quite tight - but since this is 'not visible' I think this should be OK

B Class

Received two B Classes today - B67 and B75.

Automating Signals

In preparation of buying some signals for the layout, I considered the prospect of placing a couple of Home signals on the layout. I wanted to control these signals with a button and make the signal drop to red after the train goes past it.

I saw this as two issues:

1. The ability to control the signal just like in CTC and to have the circuit detect the passing of a train to drop the signal to red.

2. The detection circuit.

Now, railpage user JLB51 has helped me tremendously. He provided me with a circuit that uses two 555 ICs. The first 555 is used to drive the RED led whilst the second is used to drive the GREEN. The first 555 is set up as a bistable circuit whilst the second as an Inverting Buffer or Schmitt trigger. Thanks to JLB51, I was able to create his circuit on a breadboard and to my delight the circuit worked! Here are some pictures

This one shows the signal set to Green.




This one shows the signal set to RED




Now, I need the detection circuit! Again, JLB51 has kindly provided me with some valuable information to get started on this.

New Track Plan

Well I have made some serious changes to the layout. When I first started, I thought running a train behind a backdrop at Stawell would be a good idea as this is some what realistic in that a train only goes pass the major station once. However, after laying out all the track and spending countless hours building the layout, I found that running a train behind the main station in a hidden fashion does not work at all!

There is much more pleasure derived seeing the train in motion. So I have done away with the crowded yard which was Stawell and gone totally fictional, but still somewhat based on VR prototype.

Here is the new plan. I think this will operate more realistically. Only problem now is that I don't have too many industries to shunt too.