# Harbor models smoke generator & dcc



## Nono (Jun 15, 2020)

Hi there, I am trying to retrofit a USA Trains Je1 Hudson with a Harbor Models smoke generator. My railroad works on DCC, with 22 V on the track. Harbor Models smoke generator works on 12 V DC and can draw up to 2 Amps. I found no DCC decoder with a function output handling up to 2 Amps. I purchased a DC/DC converter to reduce voltage to 12 V but it does not work (short, putting my Lenz DCC central station out). Any idea or advice you could give me ? Thanks !


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## Greg Elmassian (Jan 3, 2008)

yes, get another DC to DC converter.... obviously your failed.


run a relay from your decoder output, use the relay to switch the smoke unit.


After you get that working, you can attack synchronizing the fan with the chuffs.


Greg


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## Dan Pierce (Jan 2, 2008)

Was a diode bridge used to feed the DC to DC converter and is the converter rated for 2 amp output or more? Some heater elements draw more current when cold and draw less once warmed up and current will drop to a lower value, so what are the real ratings of the harbor unit?


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## Greg Elmassian (Jan 3, 2008)

https://www.harbormodels.com/smokegenerator.html


that is the new one, but current draw same... old ones would melt if run without fluid


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## Nono (Jun 15, 2020)

Hi Dan, I didn't use a diode and connected the DC/DC converter directly to the Lenz central station. Which type of diode should I use, connected to + or - ? Thank you for your guidance.


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## Nono (Jun 15, 2020)

The DC/DC converter is rated for 3 Amps. The smoke generator would not draw more than 1.5 and would burn at 2 Amps


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## Greg Elmassian (Jan 3, 2008)

OK, some screwy stuff here.

Hi there, I am trying to retrofit a USA Trains Je1 Hudson with a Harbor Models smoke generator. My railroad works on DCC, with 22 V on the track. Harbor Models smoke generator works on 12 V DC and can draw up to 2 Amps. I found no DCC decoder with a function output handling up to 2 Amps. I purchased a DC/DC converter to reduce voltage to 12 V but it does not work (*short, putting my Lenz DCC central station out*). Any idea or advice you could give me ? Thanks ! 



How could the DC/DC converter short the central station? Did you connect a device with a DC input to the AC signal on the tracks?


Hi Dan, I didn't use a diode and connected the DC/DC converter directly to the Lenz central station. Which type of diode should I use, connected to + or - ? Thank you for your guidance. 



OK, I guess you did. Wow. You have a DC to DC converter and you connected it to AC... didn't that sound wrong? Like hooking a car battery to your wall outlet?


OK you need a FULL WAVE BRIDGE, which is really 4 diodes in a single package. It has 2 inputs for AC (connect those to the rails, no polarity)... it has 2 outputs for DC (marked + and -) connect those to the + and - inputs on the smoke generator.


Greg


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## Nono (Jun 15, 2020)

Hi Greg,
Thank you for your reply. Not sure I understand the point about AC. I thought DCC was DC, is it AC instead ?


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## Greg Elmassian (Jan 3, 2008)

DCC is alternating current, AC.
DCC stands for Digital Command Control.... nothing to do with Direct Current 



The waveform is square wave, as opposed the sine wave in your home outlets.


But the point is that it is alternating polarity... you never feed AC into something that requires DC, you let out the magic smoke.


This page describes a full wave bridge rectifier


https://elmassian.com/index.php/lar...e/dcc-battery-rc-electronics/misc-electronics


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