Re: SAMRA Show Jan. 27th-28th

[ed.weltens@sbcglobal.net]

I think the proposal was to make it either TMCC or DCS so the switch would go between the transformer and the power controller. 

This would disable th Halt feature as you previously mentioned. 


Sent from my BlackBerry® wireless handheld  

-----Original Message-----
From: "Ira Schneider" <ira_schneider@Iname.com>
Date: Sun, 04 Feb 2007 00:45:19 
To:"ttat-members@aoot.com" <ttat-members@aoot.com>
Subject: Re: SAMRA Show Jan. 27th-28th

Scott,

I don't understand your proposal.

A DPDT switch has one set of inputs and two outputs.  If the input of the swith is connected
to the output of the TPC, where do the two outputs go?  It appears that one goes to the TIU
and the other to the track.  If that is true, where does the TIU output go?  You can't
connect both the TIU and the TPC (via the switch) to the track.

Your last paragraph talks about connecting a second track to the TIU.  Track 3
is already connected through the TIU.  It is connected to one of the Fixed Voltage
sections of the TIU.  The TIU strictly passes the input voltage through this section
to the track, superimposing the DCS signal on the power.  If you are using either
TMCC or conventional mode, the TIU is totally transparent.  (In fact, it even works
correctly if the TIU is powered off.)  If you want to run a ProtoSound 2.0 engine
on track 3, you just have to set the voltage to maximum using a CAB-1, then
use the MTH handheld to address the engine.  If you are not running a ProtoSound 2.0
engine on track 3, you would not even know the TIU is in the circuit.  This is why we
have two MTH handhelds.

By the way, this is not an acceptible solution for track 2, since the original idea was
to have track 2 completely controllable using the MTH handheld (i.e. for both
DCS and conventional mode) and only use the CAB-1 for TMCC control.  Also, we
originally had track 4 connected through the second Fixed Voltage section of the TIU.
We disconnected this on advice from an MTH engineer when we were having
complete failures of the DCS system and never reconnected it.

Ira

================================================================

On Thu, 1 Feb 2007 22:45:39 -0600, Scott A Smiley wrote:

>I  am still thinking that the switch would be right after the
>transformer.  The switch would send power to either the TIU of the TPC. 
>I realize that we would loose the ability of a halt command from stopping
>a track on the TIU as you pointed out.  This is a point that must be
>considered.  fortunately we have not used the halt button often but when
>you need it there is nothing else that would work for a track on the TIU.

>So a deviation of this idea would be to put the switch after the TPC and
>have the option of going through the TIU or not.  This would keep the
>halt command functional.  A switch would not be added after the TIU.  One
>side of the  switch  would go to the track connections and the other to
>the input side of the TIU and then the out put to the track.  To run on
>TMCC, you would only need the CAB1 and to run on MTH, you would still
>need to power up the track with the CAB1 and then the TIU.  Maybe a
>compromise????

> I would think that another track could also be done the same way so that
>we could have two tracks using the TIU if we wanted.  

>Scott





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TTAT members reflector.