Bachmann smoke generators, a question of voltage ?

[maxi-model]

I am in the process of converting my fleet of Bachmann Fn3 scale locos from track to battery powered, 6 down 5 to go. I am using 14 cell AA NiMH battery packs. I have noticed that once thought defunct smoke generators (a noted Bachmann Achilles heel) have now suddenly come to life and are producing decent levels of smoke. Happy days ! My locos include both those with the Bachmann PnP PCB and those that predate that standardized fitment.

Now the question - I have been warned that the voltage output of my standard spec' battery packs, 16.8 v fully charged, will in all likelihood burn out the generators' heating element in short order. As a result I was told I should only operate a generator once the loco has been run for a while to allow the voltage output from the batteries to subside to a more suitable levels. Old wives tale or true ? What is the ideal voltage range that these unit should operate in and are they protected by some sort of voltage regulator in a loco's circuitry ? Note - the battery conversions, as made, are delivering full battery voltage, not the ESC's variable, to such loco ancillaries as lighting and smoke generators, so they are "on" all the time the loco is switched on, or if the accessory is itself switched on separately.

Looking though all the schematics supplied with these locos there is no reference to the ideal voltage range or a description that shows a identifiable voltage regulator directly attached to the generator (as the early Climax models were fitted with). My experience tells me that somewhere on these locos circuitry there will be a voltage regulator, or multiples, to protect various devices from an over voltage. Likewise, no information pops up with an appropriate Google search. I have run my Heisler with the smoke unit switched on after an hour of running from being fully recharged. It was impressive, how I always felt a smoke generator should operate. Your thoughts please. Max

 

[JimmyB]

I recently bought a "new" Annie chassis, and though I did not have the smoke unit, the wiring was there, from the switch, and it would seem that it is track power voltage. But I could be wrong I have attached the drawing, and there is no voltage reduction that I can see.

 

[Rhinochugger]

The trouble with track power voltage with many Bachmann locos is that it is quite low if you are running at reasonable speeds.

I found that a Connie, or two double-headed Connies, were only drawing something like 10 volts (which was why I had to do something about the Mylocosound card) and the Mining Mogul, and the Centennial 4-4-0 are similar. The C-19 draws a bit more (I assume, because I push the throttle a little bit further up the slide, but it's still probably only around 12 - 14 volts.

Now, this is all well below Max's battery pack voltage

 

[Gizzy]

If you have converted to battery, then it is the current you need to be aware of, not the voltage.

Batteries can deliver much higher current than a transformer.

If the current is too high for the element in your smoke generator, then yes it might burn out, but the element should only draw what is needed unless there is a surge.

So check the current rating of your generator as well as the voltage....

 

[maxi-model]

If you have converted to battery, then it is the current you need to be aware of, not the voltage.

Batteries can deliver much higher current than a transformer.

If the current is too high for the element in your smoke generator, then yes it might burn out, but the element should only draw what is needed unless there is a surge.

So check the current rating of your generator as well as the voltage....

Thank you Gizzy & Rihno. The problem is that I do not know the current rating (draw in amps ?) of the smoke generators used. What I do remember is how uniformly feeble their performance was when used with my Train Engineer and Crest 18v/20 amp power unit. It was so bad that I just did not and bother to switch them on and use them.

Some seemed to not even work, so I dismissed that as the fabled "Ezy Blow" Bachmann problem. Admittedly I never checked the voltage at the rail head, just the TE transmitter that showed 7-8 LED's lit to show power draw. Now I have gone over to battery power these units have come to life and are producing fairly prodigious amounts of smoke when I switch them on (Well, I had to try anyway. Didn't I ?) . Nothing excessive. I had the Heisler running for quite a while and it just kept on smoking without the need for a refill.

I only mentioned voltage as this was something alluded to in George Schrayer's excellent tips pages, the one for the early model Climax. Bachmann Climax Tips.

So, are we saying that so long as the voltage available is within the normal range that could be delivered in a track powered environment it should not really matter ? Provided there isn't a fault with the smoke generator and you don't run it when dry then it will only draw the current it requires to heat the smoke fluid enough so it evaporates ? Max

 

[PhilP]

So, are we saying that so long as the voltage available is within the normal range that could be delivered in a track powered environment it should not really matter ? Provided there isn't a fault with the smoke generator and you don't run it when dry then it will only draw the current it requires to heat the smoke fluid enough so it evaporates ? Max

Basically, yes..

In an analogue environment, the smoke generator is getting (as a maximum) the voltage you are applying to the track, to make the loco run at that particular speed.

You are (I assume) feeding full battery voltage to the unit?
This will be ample for smoke production. If you feel it is too much smoke, you could always fit a 'buck' convertor voltage regulator, and turn it down a little.

PhilP.

 

[maxi-model]

Basically, yes..

In an analogue environment, the smoke generator is getting (as a maximum) the voltage you are applying to the track, to make the loco run at that particular speed.

You are (I assume) feeding full battery voltage to the unit?
This will be ample for smoke production. If you feel it is too much smoke, you could always fit a 'buck' convertor voltage regulator, and turn it down a little.

PhilP.

Thank you Phil - Yes, as per the RCS supplied conversion the smoke generator, when switched on, is receiving full battery voltage. The smoke production level is pretty much perfect - not a thin wisp as before but a not excessive healthy "plume" at a sedate speed. Of course the generator produces smoke even when the loco is at rest, if switched on. The generator starts producing smoke within a few seconds of being switched on even when well filled.

I'd be interested in knowing the type of device, a link if you have one, I could interpose between a generator and the wiring hat feeds it current if needed, Max

 

[Greg Elmassian]

You will find that extensive running at your battery voltage will melt nearby plastic, and you will need to check any wicks for burning/clogging.

These units were not designed for constant "full" voltage.

But I would suspect the extra current draw will cut your running time in half, and you will lose interest in running the smoke units full time.

Greg

 

[trammayo]

Thank you Phil - Yes, as per the RCS supplied conversion the smoke generator, when switched on, is receiving full battery voltage. The smoke production level is pretty much perfect - not a thin wisp as before but a not excessive healthy "plume" at a sedate speed. Of course the generator produces smoke even when the loco is at rest, if switched on. The generator starts producing smoke within a few seconds of being switched on even when well filled.

I'd be interested in knowing the type of device, a link if you have one, I could interpose between a generator and the wiring hat feeds it current if needed, Max

LM2596 - a kind member of this Forum showed me how to do it when the original B'mann smoke unit burnt out and I fitted a Seuth 5v one.

 

[maxi-model]

You will find that extensive running at your battery voltage will melt nearby plastic, and you will need to check any wicks for burning/clogging.

These units were not designed for constant "full" voltage.

But I would suspect the extra current draw will cut your running time in half, and you will lose interest in running the smoke units full time.

Greg

Yes, I read that these smoke generators can run at quite some temperatures. I read 900 F somewhere. I cannot help but notice some of the smoke stack options Bachmann provide have a metal pipe running their full length. Although how that would help with heat dissipation to protect surrounding plastic parts I cannot see,. It might even increase the risk as it acts a heat storage device rather than the heat being ejected upwards and out.

So, use judiciously then. But then I never used them much before. Max

 

[maxi-model]

LM2596 - a kind member of this Forum showed me how to do it when the original B'mann smoke unit burnt out and I fitted a Seuth 5v one.

Thank you Mick. LM2596 ? Might need a picture or link. I fitted a 10 mm Seuthe 6E to my battery powered GRS L&B Manning Wardel when I converted that, many years ago, to Battery/RC/sound. I will use Seuthe again on my under construction Vale of Ffestiniog and Conway Castle diesels. A little smaller unit though. Again I note that the Seuthe products are rated only by voltage.

Their 10 mm units seem to be around the £31 mark in UK outlets,. Though they are available with a much cheaper headline price if imported from the EU - But then what shipping, import and handling tariffs will one be hit with that will bump the price up ?

I have recently been quoted c £70 for a smoke unit designed specifically for a "diesel" application in large scale from one supplier in the LS market. Giving it some thought as in a loco that will cost in the region £700 when finished it does not seem that great a premium over the Seuthe units at £30 odd. Weird the logic one employs when one want's something. eh ? Max

 

[trammayo]

Thank you Mick. LM2596 ? Might need a picture or link. I fitted a 10 mm Seuthe 6E to my battery powered GRS L&B Manning Wardel when I converted that, many years ago, to Battery/RC/sound. I will use Seuthe again on my under construction Vale of Ffestiniog and Conway Castle diesels. A little smaller unit though. Again I note that the Seuthe products are rated only by voltage.

Their 10 mm units seem to be around the £31 mark in UK outlets,. Though they are available with a much cheaper headline price if imported from the EU - But then what shipping, import and handling tariffs will one be hit with that will bump the price up ?

I have recently been quoted c £70 for a smoke unit designed specifically for a "diesel" application in large scale from one supplier in the LS market. Giving it some thought as in a loco that will cost in the region £700 when finished it does not seem that great a premium over the Seuthe units at £30 odd. Weird the logic one employs when one want's something. eh ? Max

10 PCS LM2596 DC-DC buck adjustable step-down Power Supply Converter module | eBay

<li> Brand new. Conversion efficiency,Up to 92%. Module property:Non-isolation buck. Output current:Rated current is 2A,maximum 3A(Additional heatsink is required). Highest Conversion efficiency:92%. Switching frequency:65KHz. Output ripple:30mV( maximum). Voltage regulation:± 2.5%. Load...

www.ebay.co.uk

As this goes back a few years, I think it was Neil Robinson but I offer my apologies in advance if I have named the wrong person.

As you say Seuth are sold on voltage. Maximum track voltage for me is generally around 16volts.

 

[maxi-model]

10 PCS LM2596 DC-DC buck adjustable step-down Power Supply Converter module | eBay

<li> Brand new. Conversion efficiency,Up to 92%. Module property:Non-isolation buck. Output current:Rated current is 2A,maximum 3A(Additional heatsink is required). Highest Conversion efficiency:92%. Switching frequency:65KHz. Output ripple:30mV( maximum). Voltage regulation:± 2.5%. Load...

www.ebay.co.uk

View attachment 285635
View attachment 285636View attachment 285637View attachment 285638

As this goes back a few years, I think it was Neil Robinson but I offer my apologies in advance if I have named the wrong person.

As you say Seuth are sold on voltage. Maximum track voltage for me is generally around 16volts.

Edit - What is the round black cylindrical object with 4 legs. I have seen them somewhere before, I think when I was doing my Accucraft conversion and one was attached to a voltage regulator board made most generously by John Scanlon for me.



Thank you Mick. Bookmarked and in the tech tips folder for future perusal. At that price I might get in a stock for future use. Max

 

[The Shed]

Indeed, formed a 'building block' for many an installation, small footprint and functional.

 

[JimmyB]

Edit - What is the round black cylindrical object with 4 legs.

I think you will find it is a bridge rectifier, so that it does not matter which way the power comes in i.e., loco forward or reverse.

 

[PhilP]

I think you will find it is a bridge rectifier, so that it does not matter which way the power comes in i.e., loco forward or reverse.

Correct.
But if you are coming in direct from the battery (via a switch, fuse is a good idea) then the polarity will be a constant, anyway.

PhilP

 

[JimmyB]

Correct.
But if you are coming in direct from the battery (via a switch, fuse is a good idea) then the polarity will be a constant, anyway.

PhilP

Yes, should have mentioned track power

 

[maxi-model]

So we have identified it as a bridge rectifier. But as I am supplying battery power it seems I may not need it. Yes/No.. If I do need it what would I have to order, or what is the spec' of this item ? Remember I am a total noncomp' when it comes to these things. Max

 

[PhilP]

So we have identified it as a bridge rectifier. But as I am supplying battery power it seems I may not need it. Yes/No.. If I do need it what would I have to order, or what is the spec' of this item ? Remember I am a total noncomp' when it comes to these things. Max

I refer the Hon. Gentleman to post #16..

No, you do not need the bridge rectifier..

PhilP

 

[maxi-model]

OK, another silly question. The blurb says they are adjustable. How is this done and what is ther voltage range ? Might it have something to do with that little blue box with the brass slotted screw on the top ? If so would these items come with an instruction sheet or where would I find one ? Max

Edit - I have found a video that seems to nail it, even looks the same device as in the Ebay listing.

So final question, what would be a safe voltage to select for the Bachman smoke generators to avoid a "melt down", or is this an overstatement ? The Seuthe ones seem self evident. Many thanks to all, off to Ebay now to order a pack of 10. I dare say I will find other uses for these. I live and I learn as my late departed father always told me. But the again a little knowledge can ba a dangerous thing. Max