Droppers

Basic electrical and electronics, such as DC/Analog control.
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Tiddles
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Droppers

Post by Tiddles »

How to people contact droppers to a single point to contact to a DCC controller?

I am building a portable shunting layout with power feeds to the 5 sidings.
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Admin4
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Re: Droppers

Post by Admin4 »

normally with a 'bus wire' this is normally thicker wire then the droppers and runs the length of the layout (mine forms a loop under the baseboard).

You then connect the droppers up with the bus wire and its these wires that finally connect up to the DCC controller.

Depending on the size of your layout you could always run the dropper wires from their locations back to a single point, connecting them up with terminal blocks, and then run wires from this point to your DCC controller.

edit:
https://www.brian-lambert.co.uk/DCC.html has some good information on DDC bus
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End2end
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Re: Droppers

Post by End2end »

alex3410 wrote:normally with a 'bus wire' this is normally thicker wire than the droppers and runs the length of the layout
My DCC bus runs on 32/0.2mm with 16/0.2mm droppers from bus to track.
I also use 16/0.2mm power bus to point motors .
Hope it helps.
Thanks
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abenn
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Re: Droppers

Post by abenn »

I use the individual wires stripped out of twin-and-earth 15A electric cable for my "ring main" feed around the layout. For support it passes through terminal blocks screwed to the underside of the table, and I cut gaps in the insulation wherever I want to solder a dropper wire to it.
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Tiddles
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Re: Droppers

Post by Tiddles »

I was considering soldering them to a copper clad strip screwed to the underside of the board.

This would then be covered in insulation tape.
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Re: Droppers

Post by TimberSurf »

Nowt wrong with veroboard if your confidant with soldering!
Just be aware that if you get problems, its not so easy to diagnose if the connections are not easily disconnectable. If it's a fixed layout, not a good idea, but if the layout can be "turned over" to do the soldering, then it becomes a good "reliable connection" solution.
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Admin4
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Re: Droppers

Post by Admin4 »

So long as you can turn it upside down to do the soldering! :lol:

i did a video last year on a few different options for connecting droppers up to a bus wire which might be useful, some of which can be disconnected for testing if needed
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Re: Droppers

Post by Flashbang »

Tiddles wrote:How to people contact droppers to a single point to contact to a DCC controller?
<Snip>
'Droppers' are the smaller sized wires that connect the rails to the DCC bus wire or other rail feeding wires.
A DCC 'Bus' is normally the pair of thicker wires that runs around under the layout fed from the DCC systems 'Track' output. Onto the bus usually many droppers connect. It can of course also have droppers leading off to accessory decoders too.
To note:- Equally the word 'Bus' can be just one wire. An example would be a single thickish common retrun wire used for all solinoid point motor returns going back to the supply or CDU negative etc.

Droppers are generally soldered to the rails outer web or for invisible wiring to the rails underside before track laying. They connect onto the main bus at their other end. Dropper wire length rail to bus should be kept to as much of a minimum as possible. How the connection to the bus wire is made is up to the individual.... Soldering is the very best. But the use of terminal block connectors or so called suitcase connectors (Scotchlok) are also used. Some have even used Wago (Trade name) types of connectors.

The minimum wiring size I recommend for Droppers - 16/0.2mm equipment wire or similar wire. For the DCC Bus pair - 1.5mm2 solid or 32/0.2mm equipment wire.

Wiring droppers to a point is easy. Solder them to the outer stock rails of the point. Or to the stock rails underside if the point has yet to be laid.

I don't recommend the use of metal fishplates (Rail joiners) as the place to connect droppers onto. Reason is that the fishplate is the most likely place where a high resistance joint will occur. The idea of installing multiple droppers is to remove reliance on these fishplate for power and data transfer rail to rail. So using them for power and date connection is really defeatng the whole idea of multiple droppers! The fishplate should really only align the two abutting rails.
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