hornby select

[tony173]

Hi, I have a select which on power up goes 15-30-03, I guess the 15 is firmware 1.5.  When connected to my bus wire im only getting 0.14 voltage showing on my multmeter on the 00 gauge track. When I put the wires to the aux output I get 15+ . I have a 0-4-0 which runs but has no power am wired up wrong via the a-b outputs or something more ?

[Howbi]

You cannot reliably measure the output voltage from the Select or any DCC controller with an ordinary multimeter..........the track voltage is a square wave form of AC and usually shows as about 17 volts measured using the AC section of the MM.........this carries the DCC signal which is converted into DC by the decoder..........you can only connect the twin wire track feed to the A-B track output on the Select.........how your loco runs can be affected by many other issues such as secure connections from the bus, track cleanliness, condition of the motor and drive train etc...HB

[Chrissaf]

When measuring DCC Track voltage, the meter needs to be on the AC Voltage range. The DCC track signal is a 'bi-polar square wave' which means that the voltage swings both positively and negatively around a zero volt condition (indicated by the A> line in the image below). Square ,because the waveform is square in shape. See this scope image of a DCC signal.

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The AUX output is 15 volts DC. The DCC Track output will measure anything between 13 and 16 volts AC depending upon the quality of your meter. The multimeter on AC range will only be indicative of the DCC track voltage as cheaper (non true RMS) meters are calibrated to measure pure sine wave AC and not square waves, but 'even so' you should still get a reading in the indicated 13 to 16 volt range.

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I assume that when you wrote:

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I have a 0-4-0 which runs but has no power.

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You mean you can control it using DCC commands. That is to say it has a DCC decoder fitted and you are NOT using Address Zero on the Select, and that it does not seem to have enough power to pull a rake of wagons, but does move back and forth on the track under DCC controller control.

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Is everything in this statement correct? Particular the comment about having a DCC decoder fitted.

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Can you be more specific and describe what you mean about "has no power"?

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PS - Yes the 15 indicates the firmware is version 1.5

[tony173]

Hi Chris,

 

Thanks for the AC tip now reading 15.8 from the Select .  0-4-0  was non DCC ready so following  you tube I have installed a GMaster chip. When I first set up  under DC this little train could shift around subject to a clean track. It would start to move at about 35% on a controller. Now Im at 50% before movment with very little difference at between start and top speed ( not a high top speed).  So what with putting in drop wires the Select and a new chip it is a process of elimination.

 

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[96RAF]

I have no idea wha is original text and what is new text due to use of the reply button and typing in the yellow box.

Sorry cant help until the fog clears.

[Chrissaf]

Tony173,

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Can I humbly suggest that next time you do not use the blue button. This is not a 'Reply to this post' button. It is best if you write your reply in the 'Reply to this post' text box at the bottom of the page and click the green 'Reply' button. Using the blue button has just duplicated my long reply unnecessarily (which I have now removed). Not only that, but because my post that you duplicated had an image in it, your reply would have been held back for authorisation by the forum Admin.

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Not having a go, using the blue button is something all relative newbies on the forum seem to do for some reason. I blame the forum SW developers for putting it there, just where a 'Reply' button is expected to be.

[Chrissaf]

DCC control works completely differently to DC control. In DC, you get an instant reaction from the loco as you turn up the controller. In DCC there is usually a lag, this is perfectly normal. The decoder will typically be configured with 128 speed steps. This means that each speed step has a time gap between them as the loco speed slowly increases. This means that the loco starts to move slowly at first, then builds up speed gradually to the speed set on the DCC controller (this may take up to 10 or 20 seconds).  When users are used to the way that a DC loco reacts to controller knob position, then they invariably think that the DCC loco is not responding and turn the controller knob higher. This gives the impression that the controller knob has to be turned up higher before the loco starts to move. It is also normal for a loco that has been fitted with a decoder to be a little more sedate than when it was a DC controlled loco.

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Loco speed is subjective. What might be slow to you, might look perfectly normal to us,

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With the Select, the rate that the controller knob is turned also has an impact on loco control. If you turn the controller knob slowly, nothing happens. The faster you turn the knob, the more reactive the controller becomes to a change of speed. This is different on a DC controller where the loco speed is directly proportional to the controller knob position.

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The characteristics of the motor speed algorithms can (subject to decoder brand model) be fine tuned by changing CV values in the decoder. For example there are settings for 'start voltage' and other motor related settings. Unfortunately the basic Select controller can not currently make these CV changes.

[Howbi]

@tony173..........the disadvantage of the Select controller is that it is very limited in being able to look at and alter the various CVs which control the decoder, particularly CV29 which, had it been available to you, may have solved the loco poor performance.......unless you know someone with an Elite or RailMaster to help........HB

[96RAF]

The Select speed knob is direct acting with finite stops at both ends oftje range. it is the Elite knobs that are rate dependant encoders with no end stops. As Chris has said these types of  limitless speed control require you to twiddle the knob faster or slower to get the response you need.

Rob

[Chrissaf]

I stand corrected. I have an Elite and not a Select and assumed (incorrectly) that Hornby employed some consistency to their product designs.

[Fishmanoz]

Chris, now you understand more of why mine’s in the bottom drawer.  That difference in throttle knob operation is pretty much the last straw for me.