Impedance Questions

[Jumijo]

My kids have a Lionel Thomas set that requires a special Fastrack terminal track with a light connected to it. I'm told the light creates needed impedance for Thomas to operate properly (Why Lionel doesn't fix the situation is beyond me).

I'm about to begin construction of a tabletop layout and want to use regular O or O27 track. How can I create impedance on Thomas' new layout loop? Would a lighted car or caboose added to the train work or do I need to connect a light directly to the track?

Jim

[eZAK]

I never heard of that.

What happens when you do not hook up a light?

If the light is needed, I don't see why a lighted car would not work.

[Jumijo]

I've heard that the Thomas engine will buck, suddenly stop and then reverse on its own if the lighted track isn't used(?). I've never run Thomas without the lighted track, but when I bought the set, I was handed a separately boxed terminal track (labeled Thomas Terminal Track) with the light built in and told to make sure I use it. The story I was told was that it created a needed impedance. All my other trains run fine on that track, as I was assured they would.

Jim

[Roger Bielen]

I guess I was lucky I bought one of the early sets without an e-unit for the GD's and installed one myself.

[waltrapp]

Jim, MTH sells a lighted lockon that works on tubular track. I have several of them that I use on my O27 Christmas layout.

[wrmcclellan]

I have the Thomas engine and it is quite eratic on my 031 tubular rail layout, so I have to lock it in forward.

Thomas has an extremely poor roller pickup arrangement and is not made to handle any normal center rail gaps in 031 track (I think it needs no gaps at al!).

A bulb across the power input would have a minor effect of dampening some of the voltage spiking that occurs as the loco sparks its way around a layout, although I think this would not be significant enough to calm a nervous electronic e-unit.

Interesting. I have never heard this before. I wonder if Lionel is going to send me nice lighted terminal track?

Regards,
Roy

[Anonymous]

The need for a lighted lockon is due to a design flaw in the CW80 transformer. When you hit the reverse button, there is a bit of leakage on the transformer output. This is sufficient to prevent the cycling of the E-unit on some trains. Adding a load such as a lighted lockon bleeds off the leakage current.

Daniel Lang

[Jumijo]

Thanks for the info, guys. I appreciate it.

I assumed that a lighted lockon would be the way to go, but the person at the hobby store where I purchased Thomas said it wouldn't work. He said either use the lighted track or a lighted car. To me, a light is a light, no matter where it is, as long as it's drwing track power, right?

Jim

[Anonymous]

Jim,

You are right.

Dan