Points & accessory decoder

[70s kid]

I read that the Hornby points & accessory decoder enables control of points & presumably other wired items like signals etc. on DCC. One of the youtube videos I watched had decoders being soldered to the motor from the bus wire? The motors are pricey enough but decoders surely make this too expensive to be right??

I read that the points/accessory decoder can control up to four solenoid devices (whatever a solenoid is) - but I've seen also a much higher number quoted, something like 100-plus points that can be controlled with it?

How do you remember what number for each point if they are to be controlled by their number (address) - if there are a number of interconnecting points at the one location how can you remember what number fires what point?

Apologies for the naive questions everyone & thanks for all your great advice on the GNER decoder.

Gerry

[Chrissaf]

70's,

It depends upon your DCC control system. If you have Railmaster, your points are represented graphically on a screen that mimics your layout. Thus you do not have to memorise anything. You just click the point icon on the screen of the point you want to operate (throw) and the point physically changes. This of course, requires a fair amount of software configuration effort to achieve.

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If you don't have Railmaster and you don't have a good memory. Then you could draw a representation of your layout on paper and annotate it with the point address numbers so that you can refer to it before entering the number manually into your DCC controller by pressing the buttons. This is a lot more time consuming, compared to points that are just operated manually by a bank of physical switches or other manual techniques such as 'stud and probe' etc. That is to say NOT DCC controlled, but manually controlled.

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In response to some of the other queries raised in your post.

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Each Accessory Decoder individually controls a small number of points usually four but sometimes more, six or eight for example depending upon decoder brand and model. The 100+ figure comes from the fact that you can have more than one Accessory decoder - which would of course make it expensive. For example, 25 four port decoders for 100 points.

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A point solenoid is a device that has two electrical coils around a soft iron core. Within the core is a metal bar. When coil A is electrically energised by the Accessory Decoder (or a physical manual switch) the bar moves towards the coil. When the other coil (B) is energised the bar moves the other way towards the B coil. This mechanical back and forth movement is linked physically to the point throw bar, so that energising the two coils in turn remotely switches the point from one direction to the other.

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Yes you can use Accessory decoders to control other devices like signals for example as well as points.

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[70s kid]

 

[70s kid]

That's very helpful, thanks so much for taking the time tie plain; I understand better now some of the elements of DCC and point motors/signals. 

I wouldn't be thinking of Railmastet as a possible solution as I work on computers most of the day and one of the reasons I 'm getting back into model railways is to give me some non-computer activities. I like the signpost idea and had thought I might use the distance signs to do just the job and it might come to that. 

Many thanks 

gerry