I am retired now and was working on some MTH TIUs but would like to get schematics. Any place I should Look?
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Most of it is just circuits straight out of the textbooks honestly. If you look at the datasheets on the key items the example circuits are what's on the TIU PCB.
If you're doing repairs the only stuff that ever breaks are the 244 drivers, the TVS clamps and very rarely the channel mux. Okay and like 1/10000 times the 7805 for the 5V. That's about it
@LSnyd0ga posted:Any place I should Look?
Adrian is right on the money here.
Unfortunately it's a likely fact that there are no easily-accessible published schematics. Any that were likely to be used in the development of the TIU (and WTIU by extension) were generated for internal use on the original development program, and most probably copyrighted. If so they are legally protected and can't be distributed without permission. Some of us may be lucky, if we're part of MTH's repair network, to have access to them.
The only real option for the rest of us is to reverse engineer the functionality. The building blocks from textbooks and other sources that Adrian mentions are the starting point.
Over the years several OGR forumites have done this with other assemblies and products and had some success. A good example is this one, of the first version of the Lionel CW-80 transformer, from the late Dale Manquen:
It appears that if you want schematics for the TIU you'll have to generate them yourselves. Perhaps with the help of the rest of us?
Mike
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All the TIU building blocks and functionality are well described in the various MTH patents (e.g. 7210656, etc.) that are available online through the patent office. They are under the title "Control, sound, and operating system for model trains." Unlike the Z4000 patent which actually shows pieces of the detailed circuitry, the TIU-related ones do not and thus have very limited value.
If one does does an extensive OGR search on "TIU Schematics", "TIU Repairs" etc, it would be conceivable for some adventurous soul to put together a compendium of the fixes and repairs for the most common, recurring TIU problems even without having the detailed schematics.
@LSnyd0ga posted:I am retired now and was working on some MTH TIUs but would like to get schematics. Any place I should Look?
From your lips to God's ears! 
There's a lot of the electronics in model trains that it would be really useful to have schematics for.
