Date   
Re: Couple of questions

Mark Gurries
 

On Mar 10, 2015, at 6:15 PM, asychis@... [WiringForDCC] <WiringForDCC@...> wrote:
I understand that if you use a voltmeter to read AC voltage on the tracks with DCC, it is not an accurate reading, but just what is being measured? 

1) The DCC voltage plus voltage noise.  The noise is "voltage ringing which confuses the meter to read a voltage higher than it really is.  It is created by the track bus wiring physical properties interacting with DCC’s special form of AC power.

2) The DCC AC waveform is very different than what most AC volt meter are not designed to read.  Most volt meters are designed on the assumption it will only be used for he common 50/60Hz sinewave AC power we find in our power outlets.  The causes the meter to makes reading errors.  When you assume something…..

On our layout it reads about 15 volts.  I take it if nothing else, it is a relative measurement among different power districts.

Correct.

Best Regards,

Mark Gurries
Electrical Engineer
DCC Website & NMRA DCC Clinics: www.markgurries.com



Couple of questions

asychis@...
 

I understand that if you use a voltmeter to read AC voltage on the tracks with DCC, it is not an accurate reading, but just what is being measured?  On our layout it reads about 15 volts.  I take it if nothing else, it is a relative measurement among different power districts.
 
We just enabled Decoder Pro 3 using the Locobuffer usb connection and our members love it.  We also want to set up a Digitrax PR3.  Would it be best to use different tracks for Decoder Pro and PR3, or would it be ok to have them both connected to the same programming track as long as they are not used at the same time.  I expect a rotary switch would work too in order to switch from mainline power to programming using Decoder Pro3 or using the PR3.
 
Suggestions or comments?
 
Jerry Michels
Amarillo railroad Museum

Re: SE8C Momentary Switch Button "Commons"

John Fornasar
 

Thanks, Doug. Makes sense. Don't want to be the first one to fry two SE8C's to save one wire, especially considering the gazillion wires under the board for detection, signals and switches.

Re: Auto Reversing circuit rail gaps

John White
 

I just finished hooking up my reverse "Y" and turntable. The insulated gaps in my rail, from a suggestion on here, are roughly six inches away from my "Y" switch. From the "Y" switch you can enter the Turntable in about 10 inches. They both work well. Also I have them both tied into the same AR-1 and it works perfect. My rail gaps are across from each other, so I don't know  if it matters or not, but mine works.

Re: SE8C Momentary Switch Button "Commons"

dstuard@...
 

The safest approach would be for each SE8C to use its own sensor sensor common, although using  the sensor common from just one board to for all sensor switches will likely work also.  Connecting the sensor commons from two or more boards together could put some internal circuitry in parallel to the detriment of all boards concerned (i.e., don't  do it!).

Doug Stuard

SE8C Momentary Switch Button "Commons"

John Fornasar
 

I'm using two SE8C boards for signaling and turnout operation.

I will also use several momentary switch buttons to operate several of the tortoises.

On my first SE8C, I have a +VE sensor common bus running the length of the layout, and each button wired to the SW0x, and the other leg wired to the common.

Question - when wiring SE8C board #2 momentary switches, can I bridge both +VE sensor commons at the SE8C's and use the same bus, or should I use a separate bus for the second SE8C?

I don't want to risk a "smoke test" by bridging them to "experiment".


Thanks for any help!

Re: Auto Reversing circuit rail gaps

Douglas Krahn
 

I believe I read somewhere that the two gaps should be staggered by 1/8 inch..

Doug


On Tuesday, March 3, 2015 9:13 AM, "lee.hanna60@... [WiringForDCC]"


 
This may have been addressed before, so please forgive me if it has.  Do the rail gaps that separate a section controlled by an auto reverse circuit have to be opposite each other, or can they be offset?

Thanks much in advance.

Lee


Re: Auto Reversing circuit rail gaps

Vollrath, Don <dvollrath@...>
 

The insulating gaps can be directly opposite or offset. It doesn’t make any difference. If the polarity needs correcting, the short circuit created on either rail, or even both rails simultaneously, will be detected and trigger the A-R unit to fix the rail polarity problem… on both rails. After it is corrected, there will be no problem at the location of a later spaced gap crossing at the same end of the A-R section.

 

DonV

 

From: WiringForDCC@... [mailto:WiringForDCC@...]
Sent: Monday, March 02, 2015 8:58 PM
To: WiringForDCC@...
Subject: [WiringForDCC] Auto Reversing circuit rail gaps

 




This may have been addressed before, so please forgive me if it has.  Do the rail gaps that separate a section controlled by an auto reverse circuit have to be opposite each other, or can they be offset?

 

Thanks much in advance.


Lee




Re: Auto Reversing circuit rail gaps

Ross Kudlick
 

Lee,

 

I suggest checking the instructions for the specific auto-reverser you are using.

 

I am partial to the DCC Specialties PSX-AR; the instruction manual (page 9) says:

“When setting up gaps for reverse sections, we recommended that the gaps be staggered about 1/8 “. Perfectly aligned gaps may reduce the current needed for PSX-AR to reverse properly.”

We have installed them where “directly opposite” gaps pre-existed without difficulty; where new gaps were required we have off-set them.

 

http://www.dccspecialties.com/products/pdf/man_psxar.pdf

 

YMMV

Regards,

Ross Kudlick

 

From: WiringForDCC@... [mailto:WiringForDCC@...]
Sent: Monday, March 02, 2015 9:58 PM
To: WiringForDCC@...
Subject: [WiringForDCC] Auto Reversing circuit rail gaps

 

 

This may have been addressed before, so please forgive me if it has.  Do the rail gaps that separate a section controlled by an auto reverse circuit have to be opposite each other, or can they be offset?

 

Thanks much in advance.


Lee

Re: Auto Reversing circuit rail gaps

Dale Gloer
 

Bruce Petrarca, who has a lot of DCC experience, recommends that the gaps be offset by a small amount, maybe 2 or 3 tie spaces.  This is to prevent the auto reverser from being confused by nearly simultaneous inputs if the gaps are exactly opposite each other.

Dale Gloer

Auto Reversing circuit rail gaps

Lee Hanna
 

This may have been addressed before, so please forgive me if it has.  Do the rail gaps that separate a section controlled by an auto reverse circuit have to be opposite each other, or can they be offset?


Thanks much in advance.


Lee

Re: Separation Between Reverse Loop and HARE "Trigger Rails"

dvollrath@...
 

Oops... After reading the diagram again, the official answer is that you need a small section of fixed polarity track to separate the trigger rails of the Hare from the auto-reversing section.

But I wonder if that can be circumvented by powering the Hare from the A-R tracks instead of fixed polarity mains. Might be worth a try. I don't have any of these gadgets to play with.

DonV

  • 0 Attachment




    Re: DCC Interior Coach Lighting - Need A SIMPLE Circuit

    wirefordcc
     


    Here is a "simplist of circuits" for constant lighting.  It contains the LM317 that Len mentions.  There are several circuits shown.  You will need to scroll down to the fourth circuit using LEDs.


    http://www.wiringfordcc.com/gorhlite.htm#a17


    Allan Gartner

    Wiring For DCC


    Re: DCC Interior Coach Lighting - Need A SIMPLE Circuit

    jazzmanlj
     

    Some diodes such as UF4001 for rectifiers and 3 terminal regulator with input and output caps. My preference is the LM317 which is adjustable for output.


    Len Jaskiewicz

    Re: DCC Interior Coach Lighting - Need A SIMPLE Circuit

    george hohon3
     

    Very detailed and well presented, thanks.

    Hoot


    On Feb 28, 2015, at 8:20 PM, "Thomas Stephens deerpen4@... [WiringForDCC]" <WiringForDCC@...> wrote:

     

    Hoot
    Here is one solution:
    Tom



    From: "george hohon3 hohon3@... [WiringForDCC]" <WiringForDCC@...>
    To: "WiringForDCC@..." <wiringfordcc@...>
    Sent: Saturday, February 28, 2015 5:22 PM
    Subject: [WiringForDCC] DCC Interior Coach Lighting - Need A SIMPLE Circuit

     
    Can anyone provide suggestions, recommendations or links to the simplest of circuits for providing a "flicker-free" lighting circuit for LEDs for the purpose of lighting interior coach spaces, made from readily available parts, from an easy to reach supplier?  A definitive parts list would also be appreciated.  Thanks in advance.

    Hoot Gibson


    Re: DCC Peak Voltages and TVS Diodes

    mikea442
     

    The most notable decoders that fail on me are older TCS T1's. I also have many NCE D13SR's with no issues. I do not notice after a short, but I do notice the problem happens more when I start up system for running. What worked yesterday, doesn't work today.

    Mike

    Re: DCC Peak Voltages and TVS Diodes

    mikea442
     

    I do not have any sound decoders, but I do have older TCS T1's which as I mentioned are the most frequent culprits. Also have numerous NCE D13SR's with no problems.

    Mike

    Re: DCC Interior Coach Lighting - Need A SIMPLE Circuit

    Thomas
     

    Hoot
    Here is one solution:
    Tom



    From: "george hohon3 hohon3@... [WiringForDCC]"
    To: "WiringForDCC@..."
    Sent: Saturday, February 28, 2015 5:22 PM
    Subject: [WiringForDCC] DCC Interior Coach Lighting - Need A SIMPLE Circuit

     
    Can anyone provide suggestions, recommendations or links to the simplest of circuits for providing a "flicker-free" lighting circuit for LEDs for the purpose of lighting interior coach spaces, made from readily available parts, from an easy to reach supplier?  A definitive parts list would also be appreciated.  Thanks in advance.

    Hoot Gibson


    DCC Interior Coach Lighting - Need A SIMPLE Circuit

    george hohon3
     

    Can anyone provide suggestions, recommendations or links to the simplest of circuits for providing a "flicker-free" lighting circuit for LEDs for the purpose of lighting interior coach spaces, made from readily available parts, from an easy to reach supplier?  A definitive parts list would also be appreciated.  Thanks in advance.

    Hoot Gibson

    Re: Separation Between Reverse Loop and HARE "Trigger Rails"

    dvollrath@...
     

    Yes, the trigger rails can be adjacent to the auto-reverse loop tracks . See http://dccspecialties.com/products/pdf/man-hareng.pdf page 6

    DonV