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Discussion Starter · #1 ·
To clean up my signal on my MTH, TIU?

Fixed amperage, 24 volt?

And how many on the layout. 1 on the output of the TIU, any other locations?


Regards,

gg
 

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Looked it up, 28v 40 milliamps, and of course less current at the voltages most people run. 272-1119

John, what input voltage do you typically run, and what type of supply? Switching, regulated, plain transformer?

Regards, Greg
 

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Discussion Starter · #5 ·
Merci beaucoup

1x 28 volter... coming ...

gg
 

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Outside, I use a Bridgewerks Mag 15 and a UR 15 throttle. The unloaded peak potential is close to 31v input! Of couse, under any load at all it drops to 24v or less. Your mileage will vary since you don't necessarily have the same 115 hz current I have on the outside of the house.
However that is not how I normally run the system. I use the throttle to set the track voltage to 19v. My meter confirms what the MTH remote tells me - that the track voltage is 19. Then, if no one is running a non DCS locomotive, I do not touch the throttle from that point. I just turn the whole system on from the circuit breaker. (or the wall plug depending on how lazy I am)

If the track voltage is 19v the input voltage to the TIU is about 2v higher - so 21 volts. Yes, I could run it at 24v all day long. But there is no need to do that. I like to have the track voltage at that level because it wont burn out the passenger car lights. (and they dont look too bright) At about 21v input and 19v output, the light blub seems to provide an reasonable filter level without affecting anything else. I picked this bulb on purpose for the 28v input. Runing at 21v, it will last 100s of human lifetimes. My signal strenght all around the 300 foot track it 10. So the light bulb doesn't hurt.
 

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Discussion Starter · #7 ·
John, well noted.

With all this information I'm positive that I will plug everything in and flick the switch and "go". It's like any new piece of equipment, understanding the fundamentals of setup and operation goes a long way to minimize any startup frustrations.


Thanks

gg
 

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GG,

Raymond likes the 1873 bulb, says that curent plays a part.. The 1873 has long life @ 28 volts & should go way up when used @ 24 volts or less.. The lite bulb magic # is 80% of the voltage as this will extend the life about 33 times..

BulletBob
 

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Discussion Starter · #10 ·
Guys,

I was thinking Radio Shack and an off the shelf bulb with base. 24 or 28V version. My 10 amp bridgeworks would be set at 18 volts max.

Am I "off-track"?


gg
 

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GG,

Nope -- you are right on!!
According to Raymond it will work, just not as well as the other bulb.. With 18 volts it last for ever.. Pick your posion, 6 of 1 or half dozen of the other..
Hope this helps..

BulletBob
 

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Discussion Starter · #12 ·
thanks Bob,

The triplex sheduled to show up Friday or sat .... My Hudson a week later... Flurry of activity in the livingroom after that..





gg
 

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Thanks for the reply John, I'm still collecting information on DCS, mainly to help my buddies. It really helps to have real experience and the details you provided.

Interestingly enough, an 1873 bulb draws 200 milliamps at 28 volts, the radio shack bulb draws 40 milliamps, so the "filtering function" is most likely a function of the inductance of the filament of the bulb, not it's current draw.



Regards, Greg
 

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Greg,

You are probably correct, with the higher current maybe larger wire or less turns is the magic answer.. Probably has to due with the reflected radio frequency waves or there harmonics..

BulletBob
 

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I recently acquired a nice Tektronics scope (thanks Ted!), and will take it over my buddy's house next time and look at the signals, with and without a bulb.

I'd like to learn about termination "rules" on the layout itself. This is very similar to DCC layouts, in that some people have to put a resistor and a capacitor at the end of some power districts when the feed lines are very long.

Regards, Greg
 

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Sounds like the runs are getting long enough and the transitions steep enough to turn them into transmission lines, so they need to be terminated like SCSI. Twisted pair feed wires might be a good idea, too.
 

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Discussion Starter · #18 ·
So I went to:

Radio Shack
NAPA Auto

Canadian Tire
A RV dealership


A 24V halogen lamp is available from NAPA, and no one has a standard bulb.

My last stop outside of mailorder will be CATAPILLAR here in town. I believe that heavy equipment manufacturers use 24V electrical systems.


gg
 
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