TIU Power Source

It's an excellent choice!

The PH180 is an excellent transformer. LOTS of folks use it. It has a great circuit breaker. The question is how many TIU channels are you planning to use? Point being, you may want more than one.

My layout is 14x39. I use all four TIU channels. Each are fed by their own transformer. When it comes to powering the TIU itself, I use a Z500. It plugs right into the auxiliary power input port on the TIU.

I am starting with a small layout and one will suffice for now. By the way, I have an original version G Tiu. Do you know if these have TVS protection on the channels? I've read that later ones do but didn't know if this one did.

Thanks

Mark

Mark,

The early TIU's do not have TVS protection. TVS protection is dirt cheap and also easy to add.

Also, the version G TIU does not have internal fuses. If you are using an older ZW right now, I'd recommend that you add external circuit protection (Fast blow fuse or circuit breaker) between the ZW and the TIU.

Thank you that is good to know. I will wait until I get the powerhouse before using again. I do power the TIU with a radio shack power supply.

H1000,

The early TIU's do not have TVS protection. TVS protection is dirt cheap and also easy to add.

I beg to differ, however, my understanding is that every TIU ever produced has built-in TVS circuitry.

Also, the version G TIU does not have internal fuses.

That's correct.

Regardless, the Rev. G TIU is best avoided. Every other TIU since the Rev. G is superior in multiple ways.

Barry,

I think you are correct, please disregard my previous statement.

I was recalling the recent long technical post about the REV. L TIU. Remembering back, that had more to do with where the TVS Diodes were placed within the circuitry of the unit, rather than that being the first TIU with TVS installed.  Either way, TVS diodes are a cheap and easy add to any layout with or without a TIU.

One problem with the Rev. G, (probably not the only one) is the power carrying traces are too small, and they're buried in an inner layer of the PCB.  With no fuses, the trace ends up acting as a fuse when you pull excessive current through the TIU channel.  I've had several that had a channel toasted, and there's no way to repair it, it's just gone. 

What size circuit breaker would you recommend using on this. The unit is working fine as of now.

Mark,

What size circuit breaker would you recommend using on this.

That would depend upon your maximum amperage required for the trains running on each TIU channel. There are, however, two very important guidelines:

• The circuit breaker must be fast-acting, i.e., it trips as soon as the maximum load is exceeded.
• The maximum rating must be no greater than 10 amps per channel, unless operating in Passive TIU mode.

This and a whole lot more about DCS is all in MTH’s “The DCS Companion 3rd Edition!" This book is available from many fine OGR advertisers and forum sponsors, or as an eBook or a printed book at MTH's web store!

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Hello Barry I do have the first edition of your book. Regarding the TIU power source it does state in the book that it should be 22v for optimum conventional operation. I think the Lionel powerhouse puts out 19v. Does this make that much difference?

Thanks

Mark

Mark,

Regarding the TIU power source it does state in the book that it should be 22v for optimum conventional operation. I think the Lionel powerhouse puts out 19v. Does this make that much difference?

I believe that the book states that the 22 volt reference is for use with a variable channel, operating in variable mode, since the variable channel expects an input voltage of 22 volts in order to accurately display the channel's adjusted voltage. It would be quite rare, I believe, to actually need 22 volts at the tracks during conventional operation.

If an 18 volt power source is used with a variable channel, in variable mode for conventional operation, the only drawback would be that the voltage displayed on the DCS Remote (or the DCS App) would be slightly higher (about .18 volts) than the power actually sent to the tracks.

Regardless, if using a fixed channel, or a variable channel in fixed mode, 18 volts is actually the preferred input voltage. Further, the Lionel 180 watt Brick is also a fine power source for any TIU channel.

I do have the first edition of your book.

FYI, at 242 pages, the 3rd edition of The DCS Companion has a lot more information that the 1st or 2nd editions.