MTH loco question

Hi Jeff I will let the MTH users answer your primary question.

I did a  train show this past weekend outside of Boston and introduced using battery wireless control in three different O scale locos.  Now is the time to look at this option before you make your investment on track power. All the control and sounds come with this system. Unfortunately there is no easy way to interface to MTH afterwards.

For more info , please contact me off line. Don

since all I have is an old fashioned 2 rail DC layout I just wanted to make sure there isn't something I haven't thought of.

Jeff

MTH factory 2 rail locomotives with Protosound 2 or Protosound 3 will run quite well when operated with conventional DC power.  As stated above you will not be able to access sound features like whistle/horn or bell that can be activated with a typical 3 rail AC transformer.  Additionally, you will need a DC power supply and layout wiring that provides the NMRA recommended 16 volts at the rail under load to have the full speed range of the locomotive available to you.  This is also typical of other brands of dual mode sound decoders. 

When run "conventionally" Proto 2 and Proto 3 use track voltage as a speed command.  Below 8 volts the locomotive will sit and idle.  From 8 to 12 volts the locomotive will operate in the 0-20 scale mile per hour range.  12 to 16 volts covers 20 to 120 scale miles per hour.  The on board electronics will try and maintain the same speed up or down grade as long as the voltage remains constant and there is sufficient amperage available to send to the motor(s).

When Proto 3 locomotives first appeared in HO it was kind of funny reading reviews in magazines.  It turns out that Proto 3 locomotives are capable of more precise measurements speed and voltage than the test equipment used by the leading HO magazine back at that time.

      Thanks everyone for the great info. Ted, I'm using an old MRC HO power pack

   that works fine since I rarely run more than one engine at a time and speeds 

   are relatively slow. The terminal on the pack shows 20 Volts for DC so it sounds

   like I have enough. 

      Do some of the engine sounds work when you increase power or does it act

   just like a 2 rail DC loco with just motion and lights. 

 I have a loop of three rail track that I put around the tree and run extra locos on. My main layout downstairs is all two rail. Just for fun I put a two rail loco on the three rail track and used AC power with a MTH Z4000. It actually was fun to run. You get the old fashioned feel of cranking up the handle and still can do things like ring the bell and sound the horn. Even more if you play with the controls per the manual.

 If you went ahead with your purchase of some MTH two rail engines, you could add an AC power pack down the road to access extra features.

I'm using an old MRC HO power pack that works fine since I rarely run more than one engine at a time and speeds are relatively slow. The terminal on the pack shows 20 Volts for DC so it sounds like I have enough.

Jeff

MRC has made quite a few different models over the last 20, 30 or 40 years.  What exactly do you have?  20 volts DC output sounds unusual for a power pack intended for HO.

Just as important as the voltage output is the amperage.  Sound and especially smoke can gobble up more amperage than the motor(s).

When ready to run 2 rail O scale locomotives with factory installed sound decoders came on the market earlier in the 2000s there were two groups of O scalers that tended to have difficulties.

One group had smaller layouts and had been running HO power supplies that were adequate for many older O scale locomotives with no power draw beyond a 12 volt DC motor and a headlight.  When they started running locomotives that were designed to use the NMRA recommended 16 volts and that drew substantially more amperage they had predictably poor results.

The other group tended to operate larger home layouts or club layouts that had higher capacity power supplies.  Many of these power supplies were home made and conformed to no particular standard.  They had worked well for years with simple DC motors run from track voltage but could be quirky when used with modern dual mode decoder equipped locomotives that sensed the quality of the track power to determine if they were in an AC, DC or command control environment.

You are in the first group. You may or may not be OK.  Remember, amperage and voltage are equally important. 

Do some of the engine sounds work when you increase power or does it act just like a 2 rail DC loco with just motion and lights.

Protosound 2 and 3 locomotives will make labored chuff or revving prime mover sounds in response to high motor loads.  However, on a flat layout with a few cars you may not load the locomotive heavily enough to trigger them.

there is a non-linear response as you advance the throttle.

Actually the throttle response is linear and proportionate to track voltage.  But there are different slopes above and below 12 volts.

       Ted, it's an MRC loco-motion 1500. It has 3 terminals, the first one which

   is wired to track power is 20VDC. The second is 17AC and the third is marked

   22VDC. I'm somewhat electrically illiterate when it comes to volts and amps

   so I appreciate the feedback. I know the newer engines have a lot more 

   going on than just wires to the lights and motor leads. The engines I normally

   run are an old Atlas F9, a Trainman GP15 and a couple of Weaver single

   motor chain drives. They all work fine with this pack although it does get

   pretty warm if I leave a train running for a while. It's sounding like I need to

   do more research before spending a bunch of money on a nice engine only

   to find out it doesn't like my layout.

Jeff,

  Regarding research:  The operating manuals are posted on MTH's website for many of their locos if it is current or recent production;  start with the page for the loco under consideration.  I'd suggest reading the "Conventional DC operation" before purchase so that some of their operating, ah, idiosyncrasies are known to you beforehand -- the control scheme, as Mr Hikel partially explained above, is absolutely unique to them [ as a consequence of being optimized for either "classic Lionel-like" toy train or command control operation, analogue DC operation being almost an afterthought ].

And thanks to the internet, the 'magic number for your 1500 is 12va -- just a little light for 0 scale, but obviously workable.  MTH locomotives are well known amp hogs.

With best regards, SZ

Jeff

You said

it's an MRC loco-motion 1500.

It should look like this.

That power pack was near the entry level of MRC's Tech II product line.  I had two Tech II 2500's on an HO layout.  They were very popular back in the 1980s.  Yikes, that was 30 years ago!

I'm somewhat electrically illiterate when it comes to volts and amps   so I appreciate the feedback.

No problem.  Welcome to the world of modern electric trains.  Our trains today can do a lot more than they used to.  For best results it helps to have at least a basic understanding of what they do.  The Tech IIs were pretty advanced in their day and some of that technology may not work as well with locomotives that now have a lot of technology on board.

To equate volts and amps to water, volts are pressure and amps are volume of flow.  Your power pack's voltage (pressure) rating is at 0 amps (no flow).  As amps (flow) goes up the peak voltage (pressure) that it can produce goes down. 

The 12VA or 12 volts at one amp output available from this power pack is very marginal for O scale trains.  In fact, you noted that...

it does get pretty warm if I leave a train running for a while.

...which indicates that you are near the edge of its capabilities already.

Your Weaver chain drive and Atlas F9 locomtives are at least 15 and 40 years old respectively.  As you know, other than a motor and a light bulb there is nothing on board to use power so you have been able to get away with using a very HO sized power supply, at least for intermittent operation.

Your Atlas GP15 is mechanically similar to MTH diesels.  I assume that it is a plain DC version with no motor control, sound, smoke  or command electronics on board.  Add those features and you are likely out of the power capabilities of your old HO sized MRC power supply regardless of who manufactured the modern, high feature O scale locomotive.

Your Tech II, which was indeed high tech back in its day, uses pulses of higher voltage at the low end to give better slow speed performance from conventional DC locomotives.  Today's dual mode decoders do this on board the locomotive.  Providing pulsed DC track power to a locomotive that does this on board might not give the best results.

the control scheme, as Mr Hikel partially explained above, is absolutely unique to them [ as a consequence of being optimized for either "classic Lionel-like" toy train or command control operation, analogue DC operation being almost an afterthought ].

Protosound 3 O scale locomotives are unique in that they operate on conventional AC, conventional DC, DCC command control and the MTH DCS command system.  But they are like other locomotives equipped with dual mode sound decoders in that additional features require additional power and that some older technology and current technology may not work well together.

MTH factory 2 rail locomotives run very well on conventional DC as long as it is pure DC of sufficient amperage and voltage.  One popular way to get an inexpensive O scale sized DC power supply is to use an O guage AC train set transformer and rectify the output to DC.  MTH also makes the DCS commander which, in addition to being a DCS command base, is an excellent conventional DC power pack.

I have used one to run MTH and other O and HO locomotives with very good results.  It also has about 8 times the power of your tech II so you would not have to worry about overheating it under continuous operation.