Is there a problem with the voltages being lower than 18 volts, 12-14 volts? I'am running some 12 volt lamps on the track power. It seams to work fine, but I thought I would check it out with some of you. I'am running the Coors Light train.

Could someone give me some help on this?

Last edited by MONK
Original Post

You'd probably be marginal with 12V for that train, it has lots of smoke units.   Why not just use a diode string to drop the voltage to the lights to 12 volts and keep the track voltage at 18 volts?  Of course, you could also just supply a small power supply for the 12V lights and not run them from track power as well.

gunrunnerjohn posted:

You'd probably be marginal with 12V for that train, it has lots of smoke units.   Why not just use a diode string to drop the voltage to the lights to 12 volts and keep the track voltage at 18 volts?  Of course, you could also just supply a small power supply for the 12V lights and not run them from track power as well.

John, I love how you electrically smart guys throw out stuff like "use a diode string"   It's not a criticism at all, it's just that to those of us not so educated that's a task not well understood.  I enjoy reading all of your comments though so keep them up!!

Again, in fun, not in criticism.

- walt

Walt, I figure if there's any interest, I expand the answer to give details.  Saves a lot of typing when they're not interested.

I like GRJ's approach, for there is always a reader that would like to get a bit more info.  Maybe the original poster already knows some added fact, but others welcome the new knowledge.

In that vein, I would add that for most 12-volt bulbs that would be used on a layout, there is an 18 volt replacement.

I find that below 14 volts, operation becomes somewhat iffy.

Thank you John, but I already had those same ideas. With what I'am doing the track power is the way to go. I'll let you know latter what I'am doing.

thank you MONK

Last edited by MONK

John has always come through for me with his knowledge and expertise. I've learned so much from this forum from guys like John. And all you other guys whose names I can't remember at this moment. I don't know if I could have done this hobby without this forum. Thanks, John for all you do for making guys like me to understand this wonderful hobby of trains.

What is the Amp rating for each of the four outputs?

thank you MONK

The TIU is rated for 10 amps on each channel.

Prairie Land Junction posted:

John has always come through for me with his knowledge and expertise. I've learned so much from this forum from guys like John. And all you other guys whose names I can't remember at this moment. I don't know if I could have done this hobby without this forum. Thanks, John for all you do for making guys like me to understand this wonderful hobby of trains.

You do understand that my comment was meant 100% light-hearted, right?  John and I have "known" each other for many years and I think John knows that I would NEVER be critical of him.

- walt

We OK Walt.   I took it the way you meant it.

Thank you John. I'll post some pic's later to show whats going on.

MONK posted:

Is there a problem with the voltages being lower than 18 volts, 12-14 volts? I'am running some 12 volt lamps on the track power. It seams to work fine, but I thought I would check it out with some of you. I'am running the Coors Light train.

Could someone give me some help on this?

If all's well at 12V then you're OK.  12V is plenty of voltage to drive the smoke units.  The Protosound smoke units including those in the Coors reefers simply draw more current at lower track voltages to maintain a constant-smoke volume.  That is, if you drop the voltage from 18V to 12V, the current going to the smoke unit will essentially increase by about 50% to compensate for the lower voltage.  Note that smoke current is a fraction of the overall engine current so you might not even see a 50% change on a Z4000 current readout if you happen to be using that.  This is similar to how constant-brightness lighting works in PS - you don't need the "full" 16-18V to run the lights...they will stay constant-brightness as 12V too by drawing a bit more current but again you might not even notice the increase on a meter.

You generally run into a top speed limitation when operating at 12V (rather than 16-18V).  Obviously dependent on load, climbing grades, going around curves, etc. but I'd guess that on a typical Coors consist you might only reach ~50 sMPH if "only" 12V on the track.  In other words, command 100 sMPH and you'll top out at something less.  But the constant-lighting and smoke operation will be the same as that with the "full" 16-18V on the track.