Accessory decoder, do I need one with the Select DCC controller?

[annagr]

I am thinking of getting surface mounted DCC point motors for 4 point on my DCC layout. I have the Select controller, which is supposed to be able to operate points according to what I understand from the description (I may be wrong here). Does the Select controller need the separate accessory decoder as well or does it control point motors without it?

[jane1707819582]

Yes you will need an accessory decoder to work your points.The select addresses start at 61 to 99.

[96RAF]

Even if you are controlling the track on DCC you can choose to control your point by DCC from your Select or manually using switches just like a DC track.

[Chrissaf]

In terms of the description that you have read (unless you can quote exactly word for word what it said and state where you read it) probably meant to say that you can use the Select to operate points, but would need an Accessory Decoder to do so.

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The Select does have an AUX output on it that theoretically could be used to operate points in DC Analogue mode without the use of an Accessory Decoder. The issue with that is that point motors require a lot of current to operate robustly, and the Select standard supply is only 1 amp. So if you used the Select AUX output to operate point motors you would likely experience issues of points not operating correctly AND/OR loco control being affected because every time you operated a point the DCC side of the Select controller would be starved of power (this very issue has been reported before on the forum).

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There is a 'workaround' to this lack of current (power) issue, and that is to connect the Select AUX output to the input of a CDU (Capacitor Discharge Unit) then use the output of the CDU to operate the points. Hornby do not make or sell CDUs, but they are 'cheap as chips' and available from all good model railway retailers.

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But in all honesty I would reserve all the current (power) of the limited Select 1 amp supply for operating locomotives and trains, unless an Accessory Decoder is used.

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Never ever use the DCC track output of a DCC controller to operate points directly UNLESS you include an Accessory Decoder to interface the two (points & controller).