Alternatives to model train transformers

Sounds good! I would also like to hear some input from the forum electrical gurus.

What would concern me about having so much power is the amp rating and if I would have to change the circuit breaker in my panel box or add new wiring from my breaker box for such a large transformer. I was an electrician's helper for a few years and went to vo-tech school for electrical work. The room I have for my trains only has a 15 amp breaker. I am using several MTH Z-1000's that I have, got them at a great price train shows.

Lee Fritz

For the record, in case there was any question, all of the Lionel PowerHouse bricks are pure sine wave power supplies as well, but with better overload protection sized more in line with the needs of the application(s) they were designed for.

I see that these transformers have dual primary windings.
This is the first time I've seen a transformer with two primary coils.
How are they wired / used?

phillyreading posted:

What would concern me about having so much power is the amp rating and if I would have to change the circuit breaker in my panel box or add new wiring from my breaker box for such a large transformer. I was an electrician's helper for a few years and went to vo-tech school for electrical work. The room I have for my trains only has a 15 amp breaker. I am using several MTH Z-1000's that I have, got them at a great price train shows.

You do not have the change ANYTHING! You are confusing the amp rating on the 18-volt SECONDARY with the current draw on the 110-volt PRIMARY. If the SECONDARY side of the transformer is delivering 18 amps of current at 18 volts, that's only 324 watts. 324 watts is about 3 amps of current at 110 volts.

To put it another way, if you had FOUR of these things all delivering their maximum of 324 watts, the TOTAL current draw at your breaker box would be right around 12 amps. There is no need to change any breakers or house wiring.

C W Burfle posted:

I see that these transformers have dual primary windings. This is the first time I've seen a transformer with two primary coils. How are they wired / used?

The dual primary windings enable this transformer to be used on either 110 volts or 220 volts on the primary side.

Using transformers like this is an excellent idea. They are much more cost effective and provide more watts per dollar. Just be sure to put the correct fuses/circuit breakers into the circuit to limit the maximum current draw to the track at around 10 amps and you're all set.

Rich, Anthony, (Signal tech) did tell me if I was pulling a lot of amps it would be cheaper to run the transformers on 220v house current (rather than 110v) if I have it (which I do).   But I doubt I'll ever need to go 220v.

BTW;  thanks for responding.  I thought this set-up would work, and getting the stamp of approval from someone who knows boosts my confidence.

I see that these transformers have dual primary windings. This is the first time I've seen a transformer with two primary coils. How are they wired / used?

The dual primary windings enable this transformer to be used on either 110 volts or 220 volts on the primary side.

Thanks!
I've seen drawing of transformers that had multi-taped primary windings for various input voltages. Had not seen one represented as having two separate windings as this company does.

Waddy posted:

Rich, Anthony, (Signal tech) did tell me if I was pulling a lot of amps it would be cheaper to run the transformers on 220v house current (rather than 110v) if I have it (which I do).   But I doubt I'll ever need to go 220v.

That's not correct. You pay for power by the watt-hour. You will use the same amount of power whether you use the 110 or 220 volt setup. There will be no cost difference between using 110 and 220.

Put a standard line cord on it and plug it in. DONE.

Voltage and current (amps) are  inversely  proportional 

12 volts X 2 amps = 24 watts

2 volts x 12 amps = 24 watts

the higher the   Ampcapity the larger the wire.  The larger the wire the the bigger the conduit needs to be driving up the cost of the infrastructure.  It  becomes  a scale of  economy when your building a  factory.  Not  applicable  when building a model rail road.  Power is what you buy from your  utility provider   Measured in watts and as you can see from the above math it does not change by  simply   Increasing voltage.   Simply stated 240volt  appliances are not cheaper to operate they simply require smaller wire . ��

I think you might have mentioned this setup in some posts on the WB forum on one of my train threads--if you're that Waddy. This system sounds like a great solution!

Jeff C

Several years ago I bought 2 Hammond transformers. They are 18 volts at 10 amps each. If memory serves they were about $65 dollars each. Provide more power than I will ever use. Considerably less $$ than the ones above.

I've been using non-traditional power supplies to run my trains for years, and love them.

There are three 20A supplies on this panel. Each transformer is 6.3V. Gang three together in series, and you get 18.9V. One neat side effect of doing it this way, is all the taps you can take out between min and max voltage. The taps are brought out to the terminal strips just to the right of the transformers. At one point I decided to limit the max voltage to the track, and it was a simple matter of moving a jumper down a notch. To the right of the tap breakout terminals, are the over current protection and distribution system. Those yellowish things are 6A Polyfuses, one per power district on the layout. There is a second panel just like this on the other side of the room.

This is a great thread. Has anyone used one of these sources with a variable output voltage for conventional control, or strictly for constant voltage situations?

I hooked up my MTH z500 controller (throttle, horn and bell, reverse) to the MPI 650-36 so I could run an older conventional Lionel locomotive and it ran that just fine.  I don't know how many amps that little controller can handle, but I had a 3 amp fuse between the transformer and controller so I knew I wouldn't overload it.

trainman129 posted:

Several years ago I bought 2 Hammond transformers. They are 18 volts at 10 amps each. If memory serves they were about $65 dollars each. Provide more power than I will ever use. Considerably less $$ than the ones above.

I'm sure we both now have transformers with more power than we'll ever need.

But you paid about $6.50 ($65/10 amps)per amp while the ones I bought on ebay cost me about a dollar per amp ($40/36 amps).  Of course, if a person couldn't wait until one was offered on ebay, and paid the full list $175 for the MPI 650-36 online, that would be about $4.86 per amp ($175/36 amps). So while the Hammond transformers are cheap compared to model railroad transformers, they aren't really cheaper than other alternatives measured on cost per amp.  I'll bet there are other suitable transformers out there cheaper than either of the ones we bought.  I suspect the ones Elliot uses are pretty cost effective.  He has a great looking set-up.

No matter how you slice and dice it these transformers cost way less than ones designed specifically for model railroads.

jhz563 posted:

This is a great thread. Has anyone used one of these sources with a variable output voltage for conventional control, or strictly for constant voltage situations?

I use a 1000 watt Variac {tm} on the input side to vary the voltage on my 500 watt transformers. This one was built to run trains that draw over ten amps in command mode. It does not have a reversing switch (momentary for E units) or whistle and bell buttons. You would want these features if you intended to run conventional trains. By the time you add these features you would be better off just getting a Post War ZW.

These fixed voltage transformers are better suited for those who run command.

Like Waddy's these have dual coils. Unlike Waddy's the cost was $0.00/amp as they (4) were rescued from a dumpster.

Pete

Nothing wrong with using a non-toy train 18v transformer as long as it is an isolation transformer - i.e. the secondary coil is not electrically connected to the primary.  The MPI transformer datasheet shows it is an isolation transformer.  Many of the transformers I have tried to salvage from power supplies are autotransformers where the primary and secondary share the same wire (different taps from the coil provides voltage reduction).  This is a safety issue as it ties the track to the house wiring.

I use variable transformers (Variac is the trade name) ahead of the 18v transformer to adjust the output voltage.  Note that all the variable transformers I have found are autotransformers so never connect one directly to the track.

My 18v power transformers are Hammond 165 series "filament" transformers.  Available in 10, 15, and 20 amp output at 18v, part numbers 165S18, 165U18, and 165V18 respectively.  Considering today's pricing and the need for additional parts (breakers, enclosures, etc.) to incorporate these into a layout, the PH180s may be more cost effective.

My circuit breakers are 10A instant trip. 

Waddy posted:

I suspect the ones Elliot uses are pretty cost effective.  He has a great looking set-up.

No matter how you slice and dice it these transformers cost way less than ones designed specifically for model railroads.

I sort of cheated on mine. Those are leftover from my Mall of America set up, and were designed and built by an electrical engineer I used to know. They were also originally supplying DC, but I removed the rectifiers to use them for my all TMCC layout. From a cost perspective, they originally cost me quite a lot when they were built. Twenty five years later, it's like they are free.