How to connect a 5v smoke unit to track power, what resistor?

stevedenver

stevedenver

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I have 3 german made porters, circa 2000, with decoders.
i run analog

i suspect the decoder board to the 5v smoke unit in each was ‘set’ to receive 24 v track voltage , from the factory, instead of 6 or whatever lgb normally used.

i have used 2 of my porters, holding 1 in reserve to date.

When new, both smoked unusually profusely at very slow speeds, “how cool” i thought, , then burned out.

i dont know how to, nor wish to, reprogram the board.

fwiw, i also have a german ‘otto’, non decoder, into which i installed an 18v unit. Direct track voltage. Unfortunately, these mechanisms (they are the same in otto and porters) run waaay too fast before the 18v smoke unit smokes. so, that was a failed experiment.

i would like to know,
1 can i simply put a resistor in line with a lead from the smoke unit to prevent burnout?
2 if so, please tell me exactly what i need.

3 if not, should i look for a variable in line step down voltage converter, say on amazon, 24-6v, and try to stuff it in the loco?
(the ones i know are about 1”x1”x2” plastic boxes with input and output leads.

its been years since I disassembled a porter, but i recall the boiler shell as being small, due to the large lead weight.
Thanks
 
How long before they burnt out?

The decoder will (should) be set to limit the output to the smoke unit, so the 'simplest' would be to just replace the smoke units. - Of course, by default, the decoder outputs would be 'full track voltage', so it might be worth your while finding someone local who can check the decoder output for the smoke unit has been reduced.

If you pull the smoke unit up out of the stack, you should be able to tell the colour of the leads. This will indicate what voltage smoke unit is fitted.

PhilP
 
PhilP said:
How long before they burnt out?

The decoder will (should) be set to limit the output to the smoke unit, so the 'simplest' would be to just replace the smoke units. - Of course, by default, the decoder outputs would be 'full track voltage', so it might be worth your while finding someone local who can check the decoder output for the smoke unit has been reduced.

If you pull the smoke unit up out of the stack, you should be able to tell the colour of the leads. This will indicate what voltage smoke unit is fitted.

PhilP
Click to expand...
Very quickly. Like an hour of running, 3-9 v.
the leads are b and w, ie 5v.

i have replaced one unit once, same quick failure.

as i wrote, im pretty sure the out put is set to 24v. No i havent tested. But i could, i guess, with a voltmeter.
never had 5v units burn so hot, and then fail so quickly.

the locos would smoke while having such low voltage that while the headlight was very dim, the smoker operated as if at 7+ volts, in every case the track voltage was so low, the loco didnt move, yet the smoke billowed. I own many lgb locos with 5v smokers…typically, no smoke until the voltage is sufficient to move the loco, and fully light the headlights.

so back to the query:
can i use an inline resistor to prevent the burn out?
 
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Theoretically, yes..
In practice, this is not the way to do it. - Say you have 20V on the track, and want 5V across the smoker. So the resistor has to drop 15V.

A Seuthe No. 5 specification says 260mA so the power being dissipated in the resistor is 15x0.26=3.9W.

This is a lot of heat! You would need a 5W resistor. It will be bulky, and would need LOTS of air flow to keep it cool.

You either need to find someone who can alter the CV for you, or use a small 'buck' converter.
Massoth do a 6V regulator module (if still available) which just sits across the track connections, but it is bulkier than a buck converter.

PhilP
 
Excellent thank you.
again for those who dont appear to have read the entire thread,

I run analog track power, no digital

so...lets assume, most of the time i run my trains at 4-12 volts

is an in line resistor still out of the question?

(simply,
again,
i dont know how, nor care to, reprogram the smoke output voltage of the board....i am simply too ignorant, and, more to the point, fearful of making an operating loco a mess because of something i do.

fwiw this happened before when using my old MTS3. i unknowingly toggled between series and parallel..)
 
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The voltage for the smoke unit can be adjusted by a CV in most LGB engines. Lgb powers the '5' volt smoke unit with at least 6 volts. Seuthe spec is 4 to 6 volts. More volts is more smoke, too much voltage melts the plastic around the smoke unit and the melted plastic acts like glue.
 
I use 18 volt smoke generators with DCC sound decoder installations and leave the terminal at full track power. If you're running 20 volts DCC to the track, the voltage drop through the decoder is usually 1 volt or so, which will output 18 - 19 volts to the smoker, which is spot on. I've generally found the 18 volt smokers output better smoke than the 5 volt units.
 
The simplest way to operate a 5v smoke unit on analogue is to fit a 6v fixed output unit, you can connect it to the same output on your loco for the smoke unit, it will not matter what voltage is put in, obviously above 6v and your smoke unit will function adequately on 6v. I agree space MAY be a problem. Massoth 8242052 - 6V Fixed voltage.
 
Dan said:
The voltage for the smoke unit can be adjusted by a CV in most LGB engines. Lgb powers the '5' volt smoke unit with at least 6 volts. Seuthe spec is 4 to 6 volts. More volts is more smoke, too much voltage melts the plastic around the smoke unit and the melted plastic acts like glue.
Click to expand...
Do you know what that CV might be on a DCC Mogul? I can’t find it in my documentation.
 
MarcOpperman said:
Do you know what that CV might be on a DCC Mogul? I can’t find it in my documentation.
Click to expand...
It's always best to provide a LGB locomotive model number when asking a questions...........the former LGB made about 25 - 30 different models of Moguls, and Marklin has produced five since they assumed the LGB helm. Your question seems to be asking about Moguls with a factory-installed Onboard DCC decoder. Massoth made the decoders for Moguls until 2014 when Marklin started installing their own decoders, the MSD3 mfx/dcc/dc. Provide the LGB model number so we can help answer your question.
 
Cranford said:
The simplest way to operate a 5v smoke unit on analogue is to fit a 6v fixed output unit, you can connect it to the same output on your loco for the smoke unit, it will not matter what voltage is put in, obviously above 6v and your smoke unit will function adequately on 6v. I agree space MAY be a problem. Massoth 8242052 - 6V Fixed voltage.
Click to expand...

MarcOpperman said:
Thanks, Thomas. I admit that was vague and I know better. In fact, my recent posting related to this was hyper-specific, and got no responses. LGB 23194 Smoke Unit under DCC not working.

And here on MyLargeScale… Smoke function on LGB 23194 Mogul
Click to expand...
I sent you a response last night to your other posting under the DCC topic for fixing your smoker issue but it's not showning up yet........maybe the site's monitors must review and approve it first?
 
This has been covered by others but to reiterate what others have said and to give input from my experience. I have replaced smoke units in a few of my locos. Some DC and some DCC. In the DC locos, I went with 5v Smoke units so as to get decent output from slow speeds as I never liked getting only moderately decent smoke volume at medium to high speeds. In the DCC locos I'm using the decoder to manage the voltage. In the DC locos I installed the 5v Voltage Regulator from Piko.

36143 Voltage Regulator 5V (G-Scale)

It is probably way overpriced for what it is. A quick search shows many options for significantly less money on Amazon and other sources. It works well though. At the time I went with the Piko unit just in an attempt to keep money in the industry as well as a lack of electronics understanding. But now, as money gets tighter, I'd probably find another option for much less elsewhere. If/when I can though, I like supporting the companies making products for the hobby.

It is pretty small and incredibly simple to install.
 
There are several different size of buck converters, which will be your cheapest option. Provide input voltage to it above its low input rating and then set the output voltage to what you want, in this case 6-6.5V for a 5V smoke unit. In a porter the fit might be tight, which is why you need to look at the various size options of the step-down buck converters and find the one that works. There are 2 main sizes - the LM2596 (full size) and Mini 360 (as the name implies). The mini 360 is much less sensitive to adjustment and can be tough for LEDs. I've used mini 360 for a 5V Seuthe smoke unit connected to a Soundtraxx Tsunami 4400, and it works well. Input voltage is 22V. Like others have said it generates a lot of heat at that amount so many sure it has adequate airflow.
 
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