Model Railway Forum

Hi,
wouldn't mind some answers to a proposed track please.

I have a basic Hornby DCC controller.
I plan to run the Seep motors from a separate 16v PSU.
All points are insulfrog.
All tracks 009 and 00 will be DCC.
I plan to fit droppers every 2 or 3 ft to the track and onto 1mm DCC bus wires.
Questions..
Will there be enough power in the controller for that much track? there will probably be only 3 locos running at any one time.
I was thinking that the reverse loop would be a good way to turn locos around ,would it have to have a reverse loop module?
Would a fiddle yard be a good idea on that reverse loop? I could easily set a wifi cam to monitor that area as it is in the other part of the attic.

Apologies for the crappy Microsoft Paint image
Cheers Glynn

Hi

I'll try and answer your question in the same order as you have asked them. But firstly....
Powering your Seep PM1 motors from a separate 16v power supply is fine. By this I'm guessing you will not be using the Hornby Select to operate these points? If so, I would urge you to consider adding a CDU (Capacitor Discharge Unit) to the feed from the power supply. Seeps are very power hungry and a CDU will benefit their operation. Only one CDU is normally needed for the whole layout. Next comes the choice of how you actually operate these Seep motors - Point lever of the momentary style, Sprung to centre Off toggle switch's often referenced as (On)-Off-(On) type, 2 x non locking push to make press buttons per point direction or Stud and Probe. If you opt for point levers I would avoid the Hornby R044 Black lever as these do not work well with a CDU The Peco PL26 though is fine. Finally as mentioned Seeps are quite power hungry, so use at least 16/0.2mm equipment wire for all wiring.
If you did want the Select to operate your point motors, then you will need to add an Accessory Decoder which provides a brief Pulse output, as an interface between the DCC system and the motor(s). The Hornby Accessory Decoder takes all its power from the DCC system but there are ones available that can have an separate power supply to feed the motors and then only uses the DCC for data commands.

The amount of power from a DCC system is not layout size dependent. Its all about how many locos you have moving plus all those that are stationary as all draw power (current) from the system. Typically a modern loco without sound will consume around 200-250milliamps(ma). Add sound and that rises to 350ma. Older locos will consume more power. The basic Select comes with a 1.0Amp power supply. This will power at least three running locos of modern design. (3 x 250ma = 750ma or 3/4 Amp) So there is a small headway in power. The good news is that the Hornby Select can have an up graded power supply safely used with it, and that provided 4Amps (4000ma). Hornby P9300 is the one to use.

A Reverse loop means that where the rails return back to the main line again the right hand rail abuts the left hand rail. Result is a full short circuit. You will need to install Insulated Rail Joiners (IRJs) at each end of the loop (2 IRJs fitted opposite each other at each end). The rails inside the now isolated sections called the Reverse Loop can be feed from the output of a Reverse Loop Module The RLM will automatically flip the loops rail polarity over to match the incoming or exiting out of phase rails polarity as required. This is done seamlessly and normally unnoticed. There are are other means of doing this reverse loops rails polarity swap, but IMO on a DCC layout using a RLM is the simplest. You can have whatever you like inside the reverse loop - Sidings etc so long as they are all feed from the RLMs output no other rail feeds are permitted in the isolated loop. You can even have more than one entrance or exit track coming into or leaving the loop, but all such must have a pair of IRJs fitted to isolate the loops rails from the rest of the layout. Note the overall length of a Reverse Loop between any entrance and any exit IRJs MUST BE GREATER that the longest ever train to travel over that loop. i.e. the whole train - loco and all carriages or wagons must fit inside the loops IRJS. It also important and especially on large Reverse Loop to ensure that only one train can ever enter or leave the loop at any one time. Any number of locos can sit inside the loops or be moved inside the loop, up to the current (Amp) limit of the RLMs output of course. Input to the RLM is form the main DCC system that's feeding the main lines.

Hi,
thanks for your reply,
when searching for the Hornby P9300 a post came up on the Hornby forum stating it would be acceptable to use one of these...
https://www.ebay.co.uk/sch/i.html?_from ... A&_sacat=0
A Toshiba power supply with the same jack size as the Hornby power supply 15v 5amp. A lot cheaper than the Hornby P9300! However I do understand if one buys cheap they may buy twice.
Bus wires...
I have read various pages on this subject on your esteemed website. Would I be correct in installing bus wires forming a T shape with wire from the PSU
supply connecting to the branch of the T and both legs of the T section left and right being equal lengths.
Is it good practice to connect into the bus wires leading from the PSU to the branch of the T? or are they best left with no connections on to them?
Once again thanks for your help.
Cheers Glynn

Hi
Your problem with all those laptop PSUs is the size of the moulded DC plug. They won't fit the Select power input connector. Hornby use a very large DC plug/socket Its 6.3mm x 3.1mm.

I'm not really understanding your question re power supplies? The power supply for the Select is not connected to a Bus at anytime - It plugs directly into the DC input socket on the Select.
The DCC output from the 'two Track' terminals on the Select can be taken out to the layout and made into a Tee shape where these two wires connect onto the Bus pair. In that the bus wires can run from this connection point out to the left and the right. Do try and arrange this so as each direction is roughly equal in overall length from the connection place, but don't get to hung up on these lengths being exact. A Mtr or so extra one way than the other wont hurt.

Hi,thanks for the reply you summed up perfectly what I was trying to say.
"Two people separated by a common language" as they say

Cheers Glynn