Showing posts with label reverse loop. Show all posts
Showing posts with label reverse loop. Show all posts

Monday, June 02, 2008

Progress Report 13 - Digital developments

When the railway was first constructed, I relied initially on the 1 amp power supply that came with the original starter set. This proved more than adequate for controlling the line's only loco. After I'd constructed the control panel, I bought another 1/2 amp power supply in case I ever needed to run two locos independently. This set-up proved adequate in the early stages of the line.
After a while, the tedium of having to dash in and out of the outhouse every time I wanted to adjust speed or to stop a train became too much to bear and so I invested in an Aristocraft Train Engineer remote control device and handset. Although I was using only a 1 amp transformer, I went for the 10 amp version as I intended (and still do when I can find the funds) to buy a track cleaning loco.

This clever little unit has done sterling service for nearly two years. Acceleration deceleration is programmable so that locos slow down and speed up realistically. Even the emergency stop and reverse buttons include smooth deceleration. What's impressive is that packed into this little unit is a wealth of expansion potential. For example, you can run up to ten transmitters through the one receiver (not that I have ten rail-keen friends or relatives). Also, it is possible to put receivers in each loco and have them independently controlled. However, all I wanted was the most straightforward and simple control - a remote radio-controlled replacement to the standard controller. All I had to do was attach two wires, insert the batteries into the handset and away I went!
Eventually, I invested in a 10 amp transformer / power supply which was quite expensive (c £60.00) but well worth the investment as it meant I'd have plenty of expansion potential for that day when the track cleaning loco or even the double Fairlie arrived!

I was also considering buying the additional switch controller, which would have enabled me to switch between various sections of track and hence run more than one train at the same time. However, some unexpected back-pay was ploughed into buying a secondhand parallel MTS Central Station, transformer and handset at a very reasonable price from Garden Railway Centres. I'm not convinced the price of these products is realistic, the prices do seem overly inflated given the cost of consumer electronics these days, but it does provide me with a lot more flexibility in terms of expanding the system. Although fiddly, I found the fitting of of the decoders (£50-60 each!) quite straightforward (see How I fitted the loco decoders). In addition, I purchased a reverse loop module which detects the short-circuit created when a loco runs into or out of a loop and automatically reverses the current. Again, this was extremely straightforward to add into the wiring as I had already run the wiring from the loop back into the outhouse to the a DPDT reversing switch in the control box. Although now no longer necessary, I am keeping the control box and the electrical sections as I will still want to run unchipped locos from time to time. For example, I have a gandy dancer which I'm not going to bother to chip for those occasions when my young nephew visits.

I was quite impressed with the system - for a while! Despite adding an extension cable to the Loco Remote (the Hornby Trains DCC cable uses the same connectors), the inconvenience of once again being tied by the cable length to the outhouse became too frustrating, particularly when I added the extension to the line. So, although I had severely overspent this year's budget, I splashed out on a wireless transmitter and receiver (which was not far short of the cost of the entire Aristo Train Engineer!).

Although I am still a novice when it comes to DCC, I am already finding the benefits to be tremendous. Being able to independently control my four locos without having to substantially reorganise the wiring or change the pointwork opens all sorts of possibilities for operation.

However, were it not for my back-pay, I would have been more than happy to have continued with the Train Engineer, which to my mind is a far more cost effective way of getting wireless control and - had I gone down further down the route, would have provided me with almost as much flexibility.

[Update November 2013 - After dabbling with battery power and radio control, I have now abandoned track power completely and sold all my DCC equipment. I have no regrets. I find battery power far more reliable than using track power - no more track cleaning - no more tracking down electrical faults - no more faltering locos]

[Update May 2017 - I decided to make a video explaining my reasons for moving over from track power to battery power ]


<< Go to Progress Report 12

Sunday, June 18, 2006

How did I make the control panel

I decided from the start I would keep the control panel as simple as possible. I considered arranging the switches on a layout diagram but, as at some point in the future, I will probably extend the line, it seemed more sensible to have a bank of switches which could be re-assigned as needs arise.

Materials
A trip to my local electronics store (Maplin) provided me with the following:

1 x ABS project box (191mm x 110mm x 57mm) @ £3.79
5 x ON-OFF-ON DPDT subminiature toggle switches @ £1.94 ea
1 x ON-ON DPDT subminiature toggle switch @ £1.96
9 x (ON)-OFF-(ON) DPDT subminiature toggle switches @ £1.94 ea

Section switches
The ON-OFF-ON switches were wired up to control the sections. Flicking the switch to the right enables the right hand controller to power the section and vice versa. The ON-ON switch has been wired into the circuit for the reversing loop (track section A) to enable the polarity to be switched independently of the rest of the layout, thereby enabling reverse running over this section without short circuit.



NOTE: ON-OFF-ON switches can be switched to one of three positions left, right or centre (off)(upright).

Points switches
The (ON)-OFF-(ON) points switches were wired up us reversing switches, with a 16v DC transformer (purchased for £1.00 from a swapmeet), providing the power source:
NOTE: (ON)-OFF-(ON) means that the switch biased to remain in the centre 'off' position. After switching either way it springs back to the centre off position. This makes it ideal for point switching as the point motor needs only a momentary pulse of electricity to operate.

Finishing off
Although the the result looks like a knitting basket, it does the job:


As can be seen from the above photo, the wires from the control panel are connected to the heavier weight wiring used in the garden via connection blocks. These are hidden beneath the work-surface to provide a reasonably tidy finish.


The control box has been tested and functions well. The finishing touch will be the addition of a second transformer/controller. These seem to come up on eBay regularly for quite reasonable prices. Though, as indicated above, until I have at least one more loco, a second controller is not needed.

Monday, May 01, 2006

How did I do the electrics?

Sections
I have tried to keep the wiring as simple as possible, having only four sections:





  • The reverse loop and through station
  • The upper line from the crossover to the patio bridge
  • The lower line from the crossover to the patio bridge - also includes the terminus station
  • The storage yard
I will probably operate a simple service - no more than one or two locos 'in steam', hence having the option of being able to isolate one train while running another.
I thought long and hard about the reverse loop but decided it would be worth including it in the plan. I will thus be able to operate the layout as:
  • continuous loop
  • out-and-back (via the reverse loop)
  • and end-to end - using the through station as a terminus
The reverse loop will have a separate DPDT reverse switch to enable a train to run across the cross-over without causing a short circuit. However, this 'reversed' train will have to stop at the through station to have the polarity un-reversed.
I did contemplate using a diode bridge in the loop but as I will want trains to run in both directions around the loop had to reject it. For those who are unfamiliar with the diode bridge - four diodes are linked together:

This means that regardless of the polarity of the input from the controller, the output will remain unchanged. Thus, once the train is on the loop, the controller can be reversed and the train will continue in the same direction. If the controller is reversed quickly or via a reversing switch, the train will not appear to stop - though may hesitate slightly. As indicated above, because the polarity of the supply to the loop is fixed, dertermined by the diodes, trains can only travel in one direction around the loop.
Wiring
I have used domestic 1.5mm T/E (twin and earth) cable for the wiring. Once it situ, the cable will not be moved a great deal and hence does not need to be flexible. I also wanted something that would not lose to much voltage over the long runs in the garden. T/E cable has a single solid copper core rather than being multistranded; I felt solid cable would be less likely to deteriorate than multistrand over time.
Pointwork
I have opted for electrically operated points throughout. Initially, this decision was made for me as the LGB R3 points are only available as electrically operated versions. However, I decided that the extra wiring involved would ultimately be worthwhile as it will mean all points will be able to be operated centrally.

Where possible points are electrically linked. Hence, the two cross-over points are wired together so they will change simultaneously. This not only helps to prevent accidents, it saves on wiring - only one cable needs to be run from the control panel to the crossover.
Bonding
All rail-joints are bonded with soldered jumper leads.

A few years ago I invested in a 75 watt soldering iron and am very grateful for this decision. Once the iron has reached its operating temperature it is very easy to heat the rail to the right temperature. I intend to varnish all the soldered joints to prevent oxidisation.
From experience, I have two pieces of advice:
  • 1. Remember where you place the iron and try not to rest your hand on it!
  • 2. Make sure you pick up the iron by the handle !
I can testify (and show the scars) as to what happens if you ignore this guidance!
Control panel
The control panel has yet to be constructed - at present all wires end in an interesting cat's cradle in the lean-to. The intention is to create a switch-box which will control the four sections and the pointwork.

Wednesday, April 19, 2006

Progress report 2 - Track laying 2


A couple of half days without rain have enabled me to install some wiring and to lay a little more track. Nearly half the track is now down and a test train has been run successfully.


To fix the track in place, holes were drilled in the concrete 'breeze' blocks and rawlplugs inserted. Brass or zinc plated screws have been used to secure the track. This gives me the option to remove or re-site track if the need arises. Ultimately, the track will be ballasted - but not until it has been thoroughly tested.

The stream needs to be cleared of dead leaves as does the 'sump' into which it flows (see How I constructed the stream). For now, track-laying takes precedence.

As can be seen, I laid the cross-over which will form the link for the reverse loop. The wiring for the loop has been installed. As I will want trains to run in both directions around the loop, trains to be reversed will have to stop at the through station (as yet unnamed) while the polarity of the loop is reversed.

The track for the through station has yet to be laid, but the track-bed is in place. The wiring will be buried, once it has been soldered to the track and tested.


The terminus (again unnamed as yet) is nearly complete. The sidings need to be added - but for now I have run out of track. A trip to Bay Models (Carnforth) is scheduled for next weekend. My wife is researching her family history and is keen to visit Grange-over-Sands to see if the house in which one of her ancestors lived is still standing. Not sure yet how I will manage to fit twenty 3m lengths of rail in the car - let's hope the weather will be warm enough for the sun roof to be open!!

The link between the terminus station and the the storage area has now also been completed, together with the combined train/cat flap - a hinge needs to be added to the top of the train-flap, however! The cat-flap mechanism has been butchered from a redundant cat-flap and has been duly inspected and tested by the animal in question. This is the prototype - I will probably make a more elegant version when time permits!

While the rain fell, I completed the baseboard for storage tracks in the lean-to. I'm on more familiar ground here - 2"x1" framing with 1/2" chipboard. All I need now are some tracks - and a few more locos - and more stock.............

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