Grandpa kid proofing speed control

Which new transformers?  I have a new ZW and an old postwar ZW.  Both are fastened down such that the handles can only travel so far forward before they hit a board in front of them.  This lets me ensure they are 18 volts or less, and I think if you move them closer or put blocks in front of the handles you could be significantly more limiting.  Other types of transformers might work in a similar fashion, but many don't have any handle "overhang" so this method wouldn't work.

For "manual" conventional operation (not using a fixed 18 VAC), speed limit methods have included putting a 1 ohm, 5 watt resistor (or a 2 ohm, 10 watt) in series with the voltage to the center rail, or a series of bridge rectifiers that would reduce the voltage. In both cases, the components will get warm/hot and should be kept away from little hands. These methods have been discussed in some other threads. Here is one example (see drummer3, Dennis LaGrua posts):

https://ogrforum.com/...70#77734316074624270

There are other more complex solutions like using Zener diodes and SCR's, but the above suggestions should suffice.

I have a Williams GP38 and 6 cars set up on the floor under my layout. I wired the motors in series, and it stays on the track at full throttle with a KW. Visiting kids love it. I have trucks and cars, buildings, and lots of figures, and I let them have at it. Works for everyone.

You need to.elaborate on what "new transformers with manual operation" means.

I used the original MTH Z-4000 and was able to teach my daughter when she was still little (OMG, she 32 now) that she should look at the transformer's voltmeter BEFORE looking at the train. Worked for us and would give you the opportunity of teaching him his numbers and helping to get a jump on reading at an early age.

At the risk of going in a different direction, something I have not tried to see if it works.

On MTH PS2 and PS3 DCS controlled engines, you can set a maximum scale MPH speed. Now, the million dollar question is that stored as a setting parameter in the engine and, does that then invoke that maximum speed under conventional control?

Use a Variac-type transformer (such as this) between the house power and your train transformer to trim the voltage down to a suitable max speed.

@Vernon Barry posted:

At the risk of going in a different direction, something I have not tried to see if it works.

On MTH PS2 and PS3 DCS controlled engines, you can set a maximum scale MPH speed. Now, the million dollar question is that stored as a setting parameter in the engine and, does that then invoke that maximum speed under conventional control?

ALL of my PS2 engines have been set to max of 60MPH to help prevent runaways! Don't ask why I learned to do that. And....it is stored in each remote, so I can't say if it travels with the engine if you run it with conv trans or if the Z4K can store that max for you. I just know that with the DCS, the max, the acc rate and the dec rate can be stored. Very handy feature.

But, as soon as the engine goes on the inactive list, all those settings disappear.

On my Christmas layout, I wired in a few of the old Lionel rheostats. This way I could adjust the transformer output depending on the engine.

Car Guy Mike: Perfect!

@John H posted:

But, as soon as the engine goes on the inactive list, all those settings disappear.

That is not correct, according to the version I am using. Ever since this answer appeared, I have experimented with the DCS, and the speed is set - period. Even the MUs' speed goes from list to list. The only thing I found was with 2 hand helds on the TIU, each one can carry a Max speed, so you have to set it to be the same on each one to be safe. I set my engines to a max of 50 mph....I don't trust myself, or the grandkids, or someone else running an engine.....or even the electronics. Just thought I would verify my memory before I posted this. I do NOT run the latest version of DCS, so I can't speak to that one. Greg