MTH PS2 smoke unit operating voltages?

 there are 3 different voltages on the ps 2 boards that the remote controls. low medium and high setting depending what level of smoke you want! don't remember what  the voltages are maybe 6 or 8 but  I'm  sure a asc tech on here will chime in soon ! is is either a voltage issue or you need to replace the wick and maybe even the heater resister!

The wick indeed is captured between the resistors in a standard PS/2 smoke unit.  You want about 6-7 watts in the smoke unit for good smoke, for conventional operation you'll have difficulty getting that with variable voltage on the track.  When I bench test them, I find that 6 volts DC on the smoke resistors smokes pretty well with those units.  Note that you need a MAXIMUM of 5V on the smoke fan motor, running above that will greatly shorten it's life.

I doubt the board is useful to anyone, that's the old 5V board, and if it's blowing fuses on power-up, it's very unlikely it can be fixed for any reasonable price.

Can't help on the voltage but in answer to your other question, MTH smoke units come stock with part of the rope wicking looped up between the pair of resistors. I am sure they are designed to work that way. 

Heater power (Watts) = Voltage x Voltage / Resistance.  So doing the math, if an 8 Ohms heater, and want 6-7 Watts as GRJ suggests, Voltage = 6.9-7.5 Volts.

The PS2 electronics came in 2 versions.  As GRJ says you have so-called 5V version which used a 9V-size battery.  The electronics was in effect an integral single-piece unit and difficult to troubleshoot-repair.  The later PS2 version (so-called 3V version) could be separated into two boards.  IF you had this version, there might be some "scrap" value as this version was easier to work with.  This might be where you picked up the idea that just the "sound" board (vs. "power" board) has residual value.

It’s water under the bridge at this point but did you put a new charged battery in the engine before you ran it on the track? 

Be advised your link is to a "boost" regulator as opposed to a 'true' buck-boost regulator.  I hesitate to make hand-waving generalities, but if you apply say, 12V to a typical "boost" regulator set to 7V output, you will get an output closer to 12V than 7V.  A boost-only regulator does not have to ability to regulate the output voltage when the incoming voltage is greater than the target.

Another observation.  I can't quite tell the size of your smoke on-off slide switch.  But those "micro" slide switches don't have much current-carrying capacity (typically much less than an Amp).  In the MTH PS2/3 engines those switches carry only mA of current because this switch is only talks to the microprocessor to tell it to turn the smoke on/off - hence negligible current flow through the switch.  But as I understand your implementation, you're running all the smoke circuit power thru that switch (?) in which case it might be carrying over an Amp of current.  

banjoflyer posted:

Chris Lonero posted:

It’s water under the bridge at this point but did you put a new charged battery in the engine before you ran it on the track? 

Well not knowing any better when I first put it on the track I powered it up and waited about 30 seconds to press the DIR  button on my TMCC Cab1. It took a few tries but it eventually did run. Then I posted that scenario on the forum and found out about the "white battery of death". I replaced it with a BCR. Then all ran fine. For a few days.  Then it went kaput. Bad luck? Probably.

Maybe the white battery starts killed it. Maybe not. Like you said, "It’s water under the bridge".

mark

It did happen to me once! Any MTH engine especially PS-1 or PS-2 with a 5 volt board needs to have a new charged green battery or a new BCR before putting any voltage to it. The engine was new but unfortunately the battery was 16 years old.    Live and learn. 

The 5V boards just had a propensity to die when powered up from a long sleep, or for that matter, most anytime.  The 3V boards were much more robust, and also much easier to repair.

Mark, remember you need a MAXIMUM of 5V on the smoke unit fan, keep that in mind.

Let me know if you want to consider a cheap horn/bell board, I might be able to fix you up.

banjoflyer posted:

 

...Hopefully a unit like this will start putting out the 7VDC for the heater at low track AC voltage. 

Another observation about the latest buck-boost module.  Under Precautions, it says:

6. The module has input undervoltage protection function, the default is about 4.2V, below this value, it will automatically disconnect the output, to re-power the module can be restored (note that the module port voltage, when the input current is relatively large , Do not ignore the input voltage on the wire).

Like most DC-DC converter modules on eBay, this one has what appears to be a relatively small onboard input capacitor...it is expecting "smooth" DC from a battery or whatever.  But in this case you have AC thru a bridge.  The point being there will be ripple on your DC input to the converter and if it dips below the ~4.2V UVP threshold, the converter might essentially shut down up to 120 times per sec at low track AC voltage. Converters like this generally have a start-up sequence that can confound matters.  In other words even if you measure 5V DC (average) with a meter at the input, with the ripple from AC-to-DC conversion you might be starving the converter.

You may already have a large filter capacitor which will help low-voltage performance.  But if performance is flakey, try adding capacitance on the input - I'm talking hundreds (plural) of uF.

OR... You can by the PS-1 Version of the smoke unit and pop that top on.  It is fully regulated to run in conventional.  Add wire to the existing smoke switch as an AC on off to smoke and your set.  G

I just bought 40 of these buck's at .37 cents each 

What I do when using these for a smoke unit is wire in a small potentiometer so I can adjust the fan speed/ voltage.

Buck

The buck/boost regulators normally have two inductors.  When I look up the XL6009 data sheet, they're pretty slippery as to if that circuit will really do the wide range buck/boost.

XL6009 Data Sheet

eBay: 142513059285 looks to be one that truly clearly states it's capabilities, and it also has two inductors, one of the key indicators that I've seen for working buck/boost designs.

banjoflyer posted:

 

...Also my buddy appreciated Stan's observation about the slide switch carrying excessive current. He is going to change the set-up so that the slide switch only turns on/off an added relay or (mosfet?)  that will control the flow of power to the smoke unit. 

In general, most of these DC-DC converters have a magic regulator IC chip.  If you use one based on the XL6009 note that one of its 5 pins is "ENABLE".  This allows on/off control with a low-current control signal.  So you should not need an external added relay or transistor.  Obviously you'd need to tack in a wire.

If the spec's can be believed, it should do fine.  I actually have a very similar module, looks to be the same layout with slightly different inductors.  When I bench tested these, they did indeed to the buck/boost over a wide range. 

Note that you need a DC source, so a bridge and probably additional capacitance will be needed, I'd start with at least an extra 470uf, and preferably around 1,000uf at 35V.

@gunrunnerjohn posted:

Let me know if you want to consider a cheap horn/bell board, I might be able to fix you up.

Hi John -- I know I'm 2 years late to the party....

I have 2 requests for you:

1. Do you still have these cheap sound (whistle/bell) boards? If so, what would be the price mailed to 43068?

2. In other threads you said that you had upgraded couplers on many K-Line locos over the years, and had stock couplers. I have a K-2200-8 S2 switcher. Do you have the coupler for that? If so, what is the price?

Thanks.

Bill