Smoke generator conundrum

QUOTE (neil_s_wood @ 14 Apr 2008, 06:24) <{POST_SNAPBACK}>A couple of weeks ago I discovered the smoke unit in my Brawa BR 19 wasn't working so I installed a brand new one. It worked perfectly as you can see from the photo below. At the weekend we were having a bit of running session round at my mates house so I took it along to show the guys as they hadn't seen as smoke unit before. My mate has a NCE powercab system and the loco seemed to function fine sound, motion and light wise although when I pressed f4 for the smoke generator to work nothing happened. I spent some time faffing around with it and notice when I injected the smoke fluid in there would be a very tiny whisp of smoke but not the continuous stream of thick smoke that I normally get when I use it on my ECoS system.

I thought maybe a connection had come loose so when I got back home I was ready to take it apart to check and see what needed to be done. I fired up my ECoS first to check that it wasn't working on my system too and lo and behold it worked perfectly straight away.

Does anyone have any ideas why a smoke generator would work on an ECoS powered system and not on an NCE powercab? I'm baffled. My best guess is that the voltage on the Powercab maybe too low at 15v but this is just my speculation. I am interested as I can't see why it would work on one system and not another.

***Hello Neil

The problem isn't with PowerCab.

If the smoke unit is installed to directly replace an ex factory fitted it will probably use half wave power - ie 1 function lead with the chassis as earth. This is a common Mfr fudge - it lowers the current load on the decoder so protects it from the high current need of the smoke unit and lowers the available voltage to protect the smoke unit from early burnout via the overly high voltages of most EU made DCC systems.

So... the cause is not low voltage at the PowerCab. Exactly the opposite really. Brings us back to the NMRA standards and DCC standards interpretation.... guess which brand DOES meet the standards

so...

This half-wave power is OK with the "actually too high" rail voltages of ECOS but not with the correct "NMRA recommended rail voltage for HO" of the NCE PowerCab.

If you want to have lots of smoke on another system, change the smoke unit to one with two wires, and wire via blue and function wire, not chassis and function wire.

At the same time, look carefully at the Seuthe range - there are a couple of voltage ranges available.... The problem you face is if it will work fine at correct rail voltages you will have to be very sure you never let it run dry on the ECOS - or you risk a burn out.

Richard
DCCconcepts

QUOTE (Richard Johnson @ 14 Apr 2008, 14:15) <{POST_SNAPBACK}>***Hello Neil

The problem isn't with PowerCab.

If the smoke unit is installed to directly replace an ex factory fitted it will probably use half wave power - ie 1 function lead with the chassis as earth. This is a common Mfr fudge - it lowers the current load on the decoder so protects it from the high current need of the smoke unit and lowers the available voltage to protect the smoke unit from early burnout via the overly high voltages of most EU made DCC systems.

So... the cause is not low voltage at the PowerCab. Exactly the opposite really. Brings us back to the NMRA standards and DCC standards interpretation.... guess which brand DOES meet the standards

surprise me NCE?

so...

This half-wave power is OK with the "actually too high" rail voltages of ECOS but not with the correct "NMRA recommended rail voltage for HO" of the NCE PowerCab.

So would this mean that all American DCC systems are likely to have the same issue?

If you want to have lots of smoke on another system, change the smoke unit to one with two wires, and wire via blue and function wire, not chassis and function wire.

The Brawa one is different to most others in that it is directly soldered to two wires, whereas most others are slotted in and touch two electrical. I did not trace these wires back to see what they were connected to. Most other locos with smoke units I have Liliput, Trix, Roco are as you describe where they slot into the chassis.

At the same time, look carefully at the Seuthe range - there are a couple of voltage ranges available.... The problem you face is if it will work fine at correct rail voltages you will have to be very sure you never let it run dry on the ECOS - or you risk a burn out.

Richard
DCCconcepts

Thanks Richard This explains a lot. The problem I have is that the Roco locos with smoke generators have the smoke activated when the lights are on. The Trix Big Boy has the smoke on all the time, there is no off switch. At least with the Brawa ones I can switch it off digitally.

Would using a lower voltage smoke generator enable it to work with Powercab?

QUOTE (neil_s_wood @ 14 Apr 2008, 12:55) <{POST_SNAPBACK}>Thanks Richard This explains a lot. The problem I have is that the Roco locos with smoke generators have the smoke activated when the lights are on. The Trix Big Boy has the smoke on all the time, there is no off switch. At least with the Brawa ones I can switch it off digitally.

Would using a lower voltage smoke generator enable it to work with Powercab?

**Yes - It'l lallow them wot work with every brand.

reading the above, they can probably be re-mapped to operate separately no problem.. and the trix can be moved to a fn with a wee bit of work.

We use the #22 a lot and just finished testing 20 loc's we've fitted with them for a client. We use a powercab for testing. lots of smoke.

Richard

QUOTE (john woodall @ 14 Apr 2008, 14:58) <{POST_SNAPBACK}>Hi Richard,

My perception would be that more European locomotives have smoke units so that if the NMRA standard was to actually reflect commercial reality then surely it should have taken the European manufacturers norm rather than a best practice approach?

It's a shame that the European manufactures do not follow the NMRA standards, but given the size of the market, and the concentration of a specific German manufacturer it is not surprising that ESU went in the direction that they did.

Interesting about expectations with smoke. Personally, although Brawa locomotives come with them preinstalled, I never use them. Now if they came with a big reservoir that would allow 30 minutes of smoking then I would be keen.

John,

John, the standard does reflect the proper rail voltage for a model railway locomotive. Smoke unit should be made to that voltage, as should EU DCC systems.

the high voltage comes from the wish to make ONE system for every gauge. Sane DCC manufacturers have adjustable track voltages. Its a big omission by ESU, as most quality brands provide for it one way or another.

remember too - it affects coach bulbs and I've seen a coach with factory lighting MELT because the rail voltage was too high. Ask and retailer who sells EU rolling stock - they all hate selling the coach lighting as its a real problem

So... its the EU manufacturers of DCC wo need to get their act together.

BTW - Roco is or perhaps was the worst - I've measured up to 22 volts at the rails with the original Maus!!!

Richard
DCCconcepts

Hi

I have an NCE power cab and run smoke generators, with no problem. I use no 22's which I got from Richard. Ideal for DCC and I think the results speak for themselves.

NCE Controller, TCS T6, Decoder and 2 x No22's





martin

QUOTE (neil_s_wood @ 14 Apr 2008, 13:20) <{POST_SNAPBACK}>Ah ha the ones I use are number 11 16-22v

The 22 is for 10 to 16 v.

If you were to use the 22 on ECoS what is likely to happen if it overheats?

***Hi Neil

the decoder will regulate it to a degree - and you can adjust the level of the output on any function if U like. However if you have added that voltage dropper I sent you for the Ecos Power Supply and you make sure its off when empty, I don't think it is an issue / problem.

as MMAD said in his post though - remember ALL smoke units get hot so short bursts is always a good diea in anything other than metal bodied loco's.

Richard

The above explains a few things. Mine was the layout Neil referred to in the first place. I have a 15V power supply to the NCE Power Pro.Since my layout was originally wired for DC cab control, I have a reasonable number of feeds but still need to strengthen some areas. With that in mind, where Neil was putting the smoke oil in to the locomotve was close to a feed so it was probably close to the full 15 Volts and we saw a small puff of smoke - probably just enough voltage to heat the element but losing just enough after the cold oil hit it to produce that puff and no more! Further round the layout the voltage was probably even lower so we never actually got enough to work the smoke generator rated as 16V and above.

From all of that, the Number 22 sounds like it would do the job but, as Neil has indicated, might have problems with the higher voltage of his own ESU control unit. Are there any smoke units that are rated in between - say 14 to 18 Volts? A compromise to keep all systems happy!

Even if/when I strengthen the power supplies to the tracks (more wire, I say, MORE WIRE, Igor ... ) I still won't have more than the nominal 15V but at least I'll have more consistency around the layout.

QUOTE (SRman @ 15 Apr 2008, 15:02) <{POST_SNAPBACK}>The above explains a few things. Mine was the layout Neil referred to in the first place. I have a 15V power supply to the NCE Power Pro.Since my layout was originally wired for DC cab control, I have a reasonable number of feeds but still need to strengthen some areas. With that in mind, where Neil was putting the smoke oil in to the locomotve was close to a feed so it was probably close to the full 15 Volts and we saw a small puff of smoke - probably just enough voltage to heat the element but losing just enough after the cold oil hit it to produce that puff and no more! Further round the layout the voltage was probably even lower so we never actually got enough to work the smoke generator rated as 16V and above.

From all of that, the Number 22 sounds like it would do the job but, as Neil has indicated, might have problems with the higher voltage of his own ESU control unit. Are there any smoke units that are rated in between - say 14 to 18 Volts? A compromise to keep all systems happy!

Even if/when I strengthen the power supplies to the tracks (more wire, I say, MORE WIRE, Igor ... ) I still won't have more than the nominal 15V but at least I'll have more consistency around the layout.

**The #22 will work fine with most of your loco's Jeff

Richard