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Discussion Starter · #1 ·
I have been trying to determine the compatibility of the Digitrax DH123D decoder with the LGB MTS System when using the LGB 50111 AC Transformer to power a LGB Central Station 1, 2 or 3.

It would not be much help to know the maximum voltage of the Digitrax DH123D decoder if I do not also know the DCC track voltage that is put out by the LGB MTS System (to know if it exceeds the voltage limit of the Digitrax DH123D decoder).

Can anyone tell me what the actual LGB MTS track voltage is?

Thanks,

Jerry
 

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Discussion Starter · #3 ·
Hi BulletBob,

With a name like Bullet Bob I knew I could count on you for straight shooting. :D

With a NMRA standard of 27 volts and a LGB MTS output of 24 volts combined with the fact that the DH123D decoder seems to be working fine with no overheating, it seems that the components I am working with will most likely prove to have a long life expectancy.

Many thanks for your help,

Jerry


Posted By Road Foreman on 07/19/2008 6:33 PM
Jerry,
The MTS system has a 20 volt AC transformer for power.. To get the peak voltage you multiply 1.414 times 20 volts & get 28.28 volts.. The command station probably has a bridge rectifier input & a H bridge output.. You will loose about 2 volts per section & this will give you about 24 volts track power.. As you can see this under the 27 volts the NMRA sets for HO & larger decoders.. We all know that Soundtrax in the large scale "Shay" will not work on MTS systems unless you drop the track voltage or put bridge rectifiers in the "Shay".. I you want to be real safe you could use a 18 volt transformer.. This would give you about 21 volts track power.. As long as the transformer has the same current rating there will be no problems..
BulletBob
 

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Discussion Starter · #4 ·
Hi Bulletbob,

As I progress with my reading of my LGB Telegrams I am now up to 1996 and in the Spring 1996, Vol. 7. No. 1 (page 39) Heinz Koopmann stated that the LGB Multi-Train System always carries 24 volts.

Thanks again,

Jerry
 

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Discussion Starter · #7 ·
Hi Greg,

That is really good news to hear.

If NCE is putting out 23.4 volts and LGB claims 24 volts for MTS then that suggests to me that 24 volts is not excessive for large scale MTS/DCC.

I think this emphasizes that manufacturers should state the maximum voltage their decoders are rated for rather than the simplistic HO, O, G or whatever ratings they currently use that are (in my opinion) meaningless.

Thanks,

Jerry


Posted By Greg Elmassian on 08/06/2008 10:36 PM
I use regulated DC as a source for my NCE system, input is 27 volts, output is 23.4 or so DCC as measured by a true RMS reading voltmeter.
Regards, Greg
 

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Discussion Starter · #8 ·
Hi Greg,

Now you have brought up another matter.

I have several voltmeters that are rated for reading RMS. I have no idea what RMS is.

Your post suggests that I could use my RMS meters to measure MTS/DCC voltage. Is this correct?

**************************************************************************

Also I recently bought an Aristo-Craft CRE55468 regulated 24 volt DC power supply. Later I bought an Aristo-Craft CRE-55467 24 volt controller. I think the power supply was originally intended as a DCC power supply. I have yet to use either.

Would there be any advantage to using the CRE55468 as a power supply for a LGB MTS Central Station?

Thanks,

Jerry


Posted By Greg Elmassian on 08/06/2008 10:36 PM
as measured by a true RMS reading voltmeter.
 

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Discussion Starter · #15 ·
Hi Greg (and others),

Thanks for the explanation. It (RMS and/or DCC voltage) is not a big issue for me. I just thought that if I already had a meter that I could use that it would be nice but it is not something I would spend any money on.

I appreciate the additional information. Perhaps it will benefit someone else.

Jerry



Posted By Greg Elmassian on 08/08/2008 1:38 PM
These guys have it all correct. I should really have been more specific so I did not confuse things Jerry.
 
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