Fixed DCC sound, i.e decoder not in the loco. Will this work?

[Ruston]

A friend and I were discussing the tiny 009 Bachmann Quarry Hunslets and we came to the conclusion that if not impossible, it would certainly be very difficult, and beyond our abilities, to fit sound into the cabless version.

 

We were wondering if it is possible to run a normal, unaltered, DC loco on DCC by having a decoder and speaker in a fixed location, say inside a building on the layout. The wires from the DCC base station going to the red and black wires on the decoder, the purple ones from decoder to the speaker, all in the usual way, BUT, the grey and orange going to the track. The rails and the loco's pickups and wires acting as the wires to the motor.

 

Will this work? I don't see why it won't but is there some sort of feedback relationship between the decoder and the motor that tells the decoder what sound signal it should be putting out regarding the speed/chuff rate? If the loco suddenly lost pickup for any reason, perhaps a bad track joint or a frog on a point, the loco would stop and I can't imagine it would harm the loco, but would this damage the decoder?

 

Has anyone ever actually running a loco like this?

[pauliebanger]

Hi Dave,

 

Yes, that's possible, but the decoder's DC output to the track will leave it very vulnerable.

 

An alternative which would be less risky, perhaps, would be a non-sound decoder in the loco and the sound decoder located remotely with a speaker. Use the same address on each decoder and run in consist. Saves the DC switch/power sections issue, engine sounds can follow the road speed more closely and the layout can be DCC so other DCC locos can be run together as usual.

 

The If you use a ZIMO sound decoder it could even have several different loco types (selectable) in the project, to make this prospect a little more affordable. 

 

I've supplied a few special projects for this type of operation over the years. At least one was discussed here on RMweb, but I can' recall the layout's or title of the thread, but it was a club exhibition layout, quite successful,  so maybe someone remembers it?

 

Best regards,

 

Paul

[Nigelcliffe]

People have done it before, many times. 

 

The BIG risk is if you derail the train and short out the motor wires.  With some decoders that is "bang, one dead decoder" as they have no overload protection on the motor outputs.  With others they might withstand it, but its way outside their intended design robustness against short circuiting. 

If there were some current limiting in the circuit, so that the short could never exceed the current loading on the decoder, then it may be less likely to destroy decoders.  

 

There are many other ways to generate sounds and control locos, those alternatives may give better results.   

 

- Nigel

 

[long island jack]

 i copied this, it work well https://lancemindheim.com/about-us/wireless-headphone-sound/

[WIMorrison]

You could put the sound decoder in a carriage (or wagon) behind the loco with a load on the decoder to simulate the motor load, and then the sound will come from the same place as the loco. 

[Ruston]

22 hours ago, pauliebanger said:

An alternative which would be less risky, perhaps, would be a non-sound decoder in the loco and the sound decoder located remotely with a speaker. Use the same address on each decoder and run in consist. Saves the DC switch/power sections issue, engine sounds can follow the road speed more closely and the layout can be DCC so other DCC locos can be run together as usual.

I don't know that it will work with my controller. It can't run actual sound-fitted locos together properly as it is. It does do consisting, and two locos can be driven together, but when it comes to stopping, the F2 brake function only applies to the lead loco. The other one wants to keep going. I don't know if this is just my system (PIKO Smartcontrol lite), or if they are all like this.

 

19 hours ago, WIMorrison said:

You could put the sound decoder in a carriage (or wagon) behind the loco with a load on the decoder to simulate the motor load, and then the sound will come from the same place as the loco. 

These things can take a sound decoder - I've seen it done with the cabbed version - but the problem with the cabless versions is the speaker. Perhaps the decoder in the engine and a speaker disguised as a load on a flat wagon? Only two wires to connect and can be done via a plug. Speakers are cheap enough to have one in the lead wagon in different trains.

[Steven B]

27 minutes ago, Ruston said:

I don't know that it will work with my controller. It can't run actual sound-fitted locos together properly as it is. It does do consisting, and two locos can be driven together, but when it comes to stopping, the F2 brake function only applies to the lead loco. The other one wants to keep going. I don't know if this is just my system (PIKO Smartcontrol lite), or if they are all like this.

 

That's probably due to how the decoder is programmed to respond to functions when in a consist.

Refer to the decoder manual, or as I tend to do - reach for a PC with JMRI installed!

 

Steven B.

[WIMorrison]

If you go for the speaker in a wagon, I suggest these connectors are what you would want

 

Wired 2 Pin Male and Female Micro JST Plugs and Sockets White | Railwayscenics

 

 

[Nigelcliffe]

1 hour ago, Ruston said:

I don't know that it will work with my controller. It can't run actual sound-fitted locos together properly as it is. It does do consisting, and two locos can be driven together, but when it comes to stopping, the F2 brake function only applies to the lead loco. The other one wants to keep going. I don't know if this is just my system (PIKO Smartcontrol lite), or if they are all like this.

 

 

Its a setting in the decoder(s) and how the DCC system does consisting.  I can't remember how the DaisyII (Piko Smartcontrol Lite) does consists. 
You always have the option to manually create/end advanced consists by setting CV19 with ops-mode programming. 

 

If using advanced consists (CV19), then CV's 21 and 22 determine whether functions are controlled by the Consist address or the Locomotive address.  They can be set for each individual function so things can be controlled in whatever way you would wish. 

 

 

Or, if you always consist the same pair of locos, then the Zimo feature for allocating a function key to cause loco to join a consist could be used.   This is by far the easiest way of controlling things *if* it is always the same pair.  

 

 

 

[samfieldhouse]

I have a decoder wired to the track to run my OO9 'mine' track on my layout.

Use a good quality decoder with overload protection - I use a guagemaster DCC94.

Works for me; plus I can swap the locos between the DCC powered 'mine' and the DC shuttle powered quayside.

[WIMorrison]

Quote

Use a good quality decoder with overload protection - I use a guagemaster DCC94.

 

Hmmm - not sure if I would agree with the Gaugemaster part of that statement 😉

 

[5BarVT]

On 19/12/2022 at 13:28, pauliebanger said:

I've supplied a few special projects for this type of operation over the years. At least one was discussed here on RMweb, but I can' recall the layout's or title of the thread, but it was a club exhibition layout, quite successful,  so maybe someone remembers it?

Rockvilla Goods by 12AD MRG. Their website still has a page describing it.

Paul.