Date   

Re: snubbers for 3-wire bus

Vollrath, Don <dvollrath@...>
 

That’s right. A to B and A to C. Nothing between B & C.

DonV

 

From: WiringForDCC@... [mailto:WiringForDCC@...] On Behalf Of snboy2001@...
Sent: Wednesday, April 23, 2014 4:46 PM
To: WiringForDCC@...
Subject: [WiringForDCC] snubbers for 3-wire bus

 



My layout is wired for alternate 2-rail or trolley operation, using a toggle switch to change modes. So I have a 3-wire bus.  Call them wires A (for inside rail), B (outside rail), and C (trolley wire). I am converting to DCC.

In 2-rail mode, A is the common, B is hot, C is off.

In trolley mode, A and B are the  common, C is hot.

I am guessing that there should be two snubbers -- a snubber between A & B, and another between A & C. But NOT one between B & C.

Can anyone tell me if I have guessed right?

Thanks,
John Bishop



snubbers for 3-wire bus

John Bishop
 

My layout is wired for alternate 2-rail or trolley operation, using a toggle switch to change modes. So I have a 3-wire bus.  Call them wires A (for inside rail), B (outside rail), and C (trolley wire). I am converting to DCC.

In 2-rail mode, A is the common, B is hot, C is off.

In trolley mode, A and B are the  common, C is hot.

I am guessing that there should be two snubbers -- a snubber between A & B, and another between A & C. But NOT one between B & C.

Can anyone tell me if I have guessed right?

Thanks,
John Bishop


Re: RC snubbing in a DCCOD occupation block

Vollrath, Don <dvollrath@...>
 

To compensate for twisted pair wiring capacitance AFTER a block detector see http://www.wiringfordcc.com/blockdet.htm#a13.

DonV

 

From: WiringForDCC@... [mailto:WiringForDCC@...] On Behalf Of SBB_BLS_Bahnen@...
Sent: Tuesday, April 22, 2014 3:16 PM
To: WiringForDCC@...
Subject: [WiringForDCC] RC snubbing in a DCCOD occupation block

 



I was installing some RC snubbers on the remaining track buses yesterday, and by chance installed one on a bus that feeds power to an occupancy detection block that is monitored by one of Bruce Chubb's DCCOD circuits. As soon as I powered on to test that everything was still working properly, I noticed that the DCCOD LED connected to its output was lit even though no train was in the block. I knew this would happen but wasn't thinking when I installed that snubber. When I removed the snubber, the LED went off as expected.

The track bus that feeds this occupancy block is a branch from the a main track bus connected about 10 feet from the open end of that main bus. The main bus at the open end is terminated with its own snubber. My question is whether that snubber should be sufficient for even the branch bus that feeds this occupancy block. I don't have access to an oscilloscope, so I can't verify the DCC waveform on that branch bus.

For reference, info on the DCCOD can be found here: http://www.jlcenterprises.net/Files/DCCOD%20Information.pdf

 

Thanks,

 

-- 
Tim
Timothy A Johnson, Tucson, AZ (www.sbb-bls-bahnen.com)
European Train Enthusiasts, Central Arizona Chapter (www.ete.org)





Re: Throttle Pockets for Digitrax UT4 Throttles

Carl
 

Hello Doc Colin:

The time temperature varies with the material thickness. This last run was up to 0.130" thick and I used 350° F for 5 minutes. When I think it is ready I reach in with gloves and try to bend it. If it feels like thick leather it is ready. I have also used plastic as thin as 0.095". If you leave it in too long the plastic starts to bubble and look bad.

I thought of doubling production by using a second fry pan, but cooling in the mold needs 5 minutes too.

I also have a line heater for straight bends, much harder to avoid overheating and melting.

Carl.


Re: Digitrax DCC Track Polarity Reversal

Mark Gurries
 

The problem is not all DB150's have the same default DCC polarity on the track terminals.   It depends on the age of the DB150.  A internal design spin of the PCB ended up flipping the two track connections.  The only solution is to swap the two track connections at the Booster.


On Apr 23, 2014, at 7:23 AM, Vollrath, Don wrote:

If it works ok with the red and black wires reversed at booster 3 the red and black connections to track must be reversed somehow under the layout. You can disconnect wires from the booster and use an ohmmeter to prove what wire is connected to which rail. Or, if it works after swapping the wires at the booster ... Don't mess with it.

DonV


On Apr 23, 2014, at 8:15 AM, "richard@...<mailto:richard@...>" mailto:richard@...>> wrote:




We have a large n-scale club layout with Digitrax DCC ... we use the DCS100 as the command station, and 3 DB150s in booster only mode (with jumper wire) to provide track power to 3 districts (the DCS100 does not provide track power).



Each district is divided into 4 sub-districts using PSX-4 circuit breakers. and each sub-district is divided into 4 occupancy blocks using the BDL168.



Each sub-district has a track bus (R/B) with feeders to the rail every 2-3 feet (each piece of track has a set of feeders). The Red bus wire is connected to Rail B and the Black bus wire is connected to Rail A on the DB150s.



Now the problem ... districts 1 & 2 behave perfectly, however, when a loco passes over the double rail gap between district 2 & 3, a short occurs. We have temporarily solved the problem by reversing the track bus wires (R/B) at the offending DB150.



We have traced all the bus wiring and track feeders in the district to make sure all is well there ... it is. We have reset the DB150 to factory settings to make sure it is not acting as a reverser, and we have made sure our LocoNet wiring is solid and has no issues.



Any ideas on how this problem may be addressed?


Thanks,


Richard





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




Re: Digitrax DCC Track Polarity Reversal

Vollrath, Don <dvollrath@...>
 

If it works ok with the red and black wires reversed at booster 3 the red and black connections to track must be reversed somehow under the layout. You can disconnect wires from the booster and use an ohmmeter to prove what wire is connected to which rail. Or, if it works after swapping the wires at the booster ... Don't mess with it.

DonV

On Apr 23, 2014, at 8:15 AM, "richard@sauerbrun.com<mailto:richard@sauerbrun.com>" <richard@sauerbrun.com<mailto:richard@sauerbrun.com>> wrote:




We have a large n-scale club layout with Digitrax DCC ... we use the DCS100 as the command station, and 3 DB150s in booster only mode (with jumper wire) to provide track power to 3 districts (the DCS100 does not provide track power).



Each district is divided into 4 sub-districts using PSX-4 circuit breakers. and each sub-district is divided into 4 occupancy blocks using the BDL168.



Each sub-district has a track bus (R/B) with feeders to the rail every 2-3 feet (each piece of track has a set of feeders). The Red bus wire is connected to Rail B and the Black bus wire is connected to Rail A on the DB150s.



Now the problem ... districts 1 & 2 behave perfectly, however, when a loco passes over the double rail gap between district 2 & 3, a short occurs. We have temporarily solved the problem by reversing the track bus wires (R/B) at the offending DB150.



We have traced all the bus wiring and track feeders in the district to make sure all is well there ... it is. We have reset the DB150 to factory settings to make sure it is not acting as a reverser, and we have made sure our LocoNet wiring is solid and has no issues.



Any ideas on how this problem may be addressed?


Thanks,


Richard


Digitrax DCC Track Polarity Reversal

rsauerbrun
 

We have a large n-scale club layout with Digitrax DCC ... we use the DCS100 as the command station, and 3 DB150s in booster only mode (with jumper wire) to provide track power to 3 districts (the DCS100 does not provide track power).



Each district is divided into 4 sub-districts using PSX-4 circuit breakers. and each sub-district is divided into 4 occupancy blocks using the BDL168.



Each sub-district has a track bus (R/B) with feeders to the rail every 2-3 feet (each piece of track has a set of feeders). The Red bus wire is connected to Rail B and the Black bus wire is connected to Rail A on the DB150s.



Now the problem ... districts 1 & 2 behave perfectly, however, when a loco passes over the double rail gap between district 2 & 3, a short occurs. We have temporarily solved the problem by reversing the track bus wires (R/B) at the offending DB150.



We have traced all the bus wiring and track feeders in the district to make sure all is well there ... it is. We have reset the DB150 to factory settings to make sure it is not acting as a reverser, and we have made sure our LocoNet wiring is solid and has no issues.



Any ideas on how this problem may be addressed?


Thanks,


Richard


Re: Throttle Pockets for Digitrax UT4 Throttles

Phil Euper <peuper@...>
 

Carl
If no one speaks up, I’m sure we can find find use for
it at the club.
 
Regards
 
Phil Euper
 
 

From: Carl
Sent: Tuesday, April 22, 2014 8:43 PM
Subject: [WiringForDCC] Throttle Pockets for Digitrax UT4 Throttles
 


Hi Gang:

Just finished a run of Throttle Pockets for Digitrax UT-4:

https://groups.yahoo.com/neo/groups/WiringForDCC/photos/albums/1229122851

I don't think I'll ever need to make more if someone wants the tooling?

Carl.


Re: Throttle Pockets for Digitrax UT4 Throttles

Doc Colin <colinseggie@...>
 

Hi Carl, Very ingenious. What sort of temperature/ what signs do you get/read, that lets you know the plexiglass is ready to mold, and not "under/over" done as it were? Do you warm up the mold first?
Doc Colin

----- Original Message -----
From: Carl
Sent: Wednesday, April 23, 2014 2:43 AM
Subject: [WiringForDCC] Throttle Pockets for Digitrax UT4 Throttles

 

Hi Gang:

Just finished a run of Throttle Pockets for Digitrax UT-4:

https://groups.yahoo.com/neo/groups/WiringForDCC/photos/albums/1229122851

I don't think I'll ever need to make more if someone wants the tooling?

Carl.


Throttle Pockets for Digitrax UT4 Throttles

Carl
 

Hi Gang:

Just finished a run of Throttle Pockets for Digitrax UT-4:

https://groups.yahoo.com/neo/groups/WiringForDCC/photos/albums/1229122851

I don't think I'll ever need to make more if someone wants the tooling?

Carl.


Re: RC snubbing in a DCCOD occupation block

jazzmanlj
 

Tim,

You could try cutting the snubber cap to .047uF. Another approach would be using tranzorbs as they only conduct during voltage spikes. The further away a transient protective network/device is from the transient occurence, the less effective it is.

 

Len Jaskiewicz


RC snubbing in a DCCOD occupation block

Tim Johnson
 

I was installing some RC snubbers on the remaining track buses yesterday, and by chance installed one on a bus that feeds power to an occupancy detection block that is monitored by one of Bruce Chubb's DCCOD circuits. As soon as I powered on to test that everything was still working properly, I noticed that the DCCOD LED connected to its output was lit even though no train was in the block. I knew this would happen but wasn't thinking when I installed that snubber. When I removed the snubber, the LED went off as expected.

The track bus that feeds this occupancy block is a branch from the a main track bus connected about 10 feet from the open end of that main bus. The main bus at the open end is terminated with its own snubber. My question is whether that snubber should be sufficient for even the branch bus that feeds this occupancy block. I don't have access to an oscilloscope, so I can't verify the DCC waveform on that branch bus.

For reference, info on the DCCOD can be found here: http://www.jlcenterprises.net/Files/DCCOD%20Information.pdf


Thanks,


-- 
Tim
Timothy A Johnson, Tucson, AZ (www.sbb-bls-bahnen.com)
European Train Enthusiasts, Central Arizona Chapter (www.ete.org)


Re: Proximity of Sub Bus Wires to Main Bus Wires

Vollrath, Don <dvollrath@...>
 

The only advantages are to reduce the size of the wiring bundle, the total number of wiring feet under the layout and shorten the distance from the breakers to actual track connections. May not apply in every situation.

DonV

 

From: WiringForDCC@... [mailto:WiringForDCC@...] On Behalf Of redking56@...
Sent: Tuesday, April 22, 2014 7:51 AM
To: WiringForDCC@...
Subject: RE: [WiringForDCC] Proximity of Sub Bus Wires to Main Bus Wires

 



Don, 

 

Thanks for that information.   

 

What exactly is the advantage of keeping the local district circuit breakers near the center of the individual districts as opposed to grouping the circuit breakers near the booster and running pairs of sub bus wires out to the local power districts?

 

Rich



---In WiringForDCC@..., <dvollrath@...> wrote :

Rich, There will be no interference caused by running the separate busses alongside each other. But a better plan might be to run the main booster bus out on the layout and put the local district circuit breakers near the center of the individual districts.

DonV

 

From: WiringForDCC@... [mailto:WiringForDCC@...] On Behalf Of redking56@...
Sent: Tuesday, April 22, 2014 6:23 AM
To: WiringForDCC@...
Subject: [WiringForDCC] Proximity of Sub Bus Wires to Main Bus Wires

 



I am in the process of dividing my layout into a series of separate power districts, and I will be stringing a pair of sub bus wires for each separate power district.

 

Is there any concern about installing pairs of sub bus wires in close proximity to one another or in close proximity to the main bus wires?

 

Thanks.

 

Rich







Re: Proximity of Sub Bus Wires to Main Bus Wires

redking56@...
 

Don, 

Thanks for that information.   

What exactly is the advantage of keeping the local district circuit breakers near the center of the individual districts as opposed to grouping the circuit breakers near the booster and running pairs of sub bus wires out to the local power districts?

Rich


---In WiringForDCC@..., <dvollrath@...> wrote :

Rich, There will be no interference caused by running the separate busses alongside each other. But a better plan might be to run the main booster bus out on the layout and put the local district circuit breakers near the center of the individual districts.

DonV

 

From: WiringForDCC@... [mailto:WiringForDCC@...] On Behalf Of redking56@...
Sent: Tuesday, April 22, 2014 6:23 AM
To: WiringForDCC@...
Subject: [WiringForDCC] Proximity of Sub Bus Wires to Main Bus Wires

 




I am in the process of dividing my layout into a series of separate power districts, and I will be stringing a pair of sub bus wires for each separate power district.

 

Is there any concern about installing pairs of sub bus wires in close proximity to one another or in close proximity to the main bus wires?

 

Thanks.

 

Rich





Re: Proximity of Sub Bus Wires to Main Bus Wires

Vollrath, Don <dvollrath@...>
 

Rich, There will be no interference caused by running the separate busses alongside each other. But a better plan might be to run the main booster bus out on the layout and put the local district circuit breakers near the center of the individual districts.

DonV

 

From: WiringForDCC@... [mailto:WiringForDCC@...] On Behalf Of redking56@...
Sent: Tuesday, April 22, 2014 6:23 AM
To: WiringForDCC@...
Subject: [WiringForDCC] Proximity of Sub Bus Wires to Main Bus Wires

 




I am in the process of dividing my layout into a series of separate power districts, and I will be stringing a pair of sub bus wires for each separate power district.

 

Is there any concern about installing pairs of sub bus wires in close proximity to one another or in close proximity to the main bus wires?

 

Thanks.

 

Rich





Proximity of Sub Bus Wires to Main Bus Wires

redking56@...
 

I am in the process of dividing my layout into a series of separate power districts, and I will be stringing a pair of sub bus wires for each separate power district.


Is there any concern about installing pairs of sub bus wires in close proximity to one another or in close proximity to the main bus wires?


Thanks.


Rich


Re: Common Metric Wire Sizes

jazzmanlj
 

Hi Allan,

Just a comment about your comparison of solid vs. stranded wire; skin effect and AC resistance.

In general for frequencies under 100kHz, skin effect should be negated as it's so miniscule. Stranded wire does not really reduce scin effect as the conductors are uninsulated, so the model is that of a solid conductor. Litz wire does reduce skin effect as it's multiple strands of insulated magnet wire twisted. The size of the strands are optimized for frequency ranges, generally starting near 1MHz and above.

AC resistance is another subject that does get quite technical. It comes into play in 'high power' high frequency systems.  Under 100kHz it should not even be mentioned to the general modeler.

Regards,

Len Jaskiewicz


Re: Common Metric Wire Sizes

Vollrath, Don <dvollrath@...>
 

The table additions are great. Although the big one is a little over the top even for the rivet counters.

DonV

On Apr 19, 2014, at 2:08 PM, "bigboy@WiringForDCC.com<mailto:bigboy@WiringForDCC.com>" <bigboy@WiringForDCC.com<mailto:bigboy@WiringForDCC.com>> wrote:




This is for modelers needing metric wire sizes. I have revamped the charts for metric wires.

For feeders, go to: http://www.wiringfordcc.com/track_2.htm#a14

For bus wires, go to:: http://www.wiringfordcc.com/track_2.htm#a26

if you want a detailed chart of US and metric wires for general use, go to: http://www.wiringfordcc.com/wire_sizes.pdf


This is for those that have been involved with the recent discussions of metric wire. After our discussions earlier in the week, I continued to surf the web and think about how to present information on US and metric wire that was simple. I didn't want the typical non-US modeler to have buy a wire gauge or a caliper to measure wire. I wanted something just as simple for the non-US modeler as it is for the US modeler. The complicating factor is that there is not a one-for-one metric equivalent to US wire sizes. It took me a week, but I think I achieved my goal. The end result is that it is so subtle, the casual reader won't notice I made a change. Any new modeler visiting my site won't know notice there was ever a problem and will know which wire they need to buy.


Enjoy!


Allan Gartner

Wiring For DCC


Re: Common Metric Wire Sizes

Doc Colin <colinseggie@...>
 


 Hi Allan,
 Very good and succinct. No short term headaches/expense there!
Well done!
 Doc Colin

----- Original Message -----
From: bigboy@...
Sent: Saturday, April 19, 2014 9:07 PM
Subject: Re: [WiringForDCC] Re: Common Metric Wire Sizes

 

This is for modelers needing metric wire sizes.  I have revamped the charts for metric wires.

 For feeders, go to:  http://www.wiringfordcc.com/track_2.htm#a14

For bus wires, go to::  http://www.wiringfordcc.com/track_2.htm#a26

if you want a detailed chart of US and metric wires for general use, go to:  http://www.wiringfordcc.com/wire_sizes.pdf


This is for those that have been involved with the recent discussions of metric wire.  After our discussions earlier in the week, I continued to surf the web and think about how to present information on US and metric wire that was simple.  I didn't want the typical non-US modeler to have buy a wire gauge or a caliper to measure wire. I wanted something just as simple for the non-US modeler as it is for the US modeler.  The complicating factor is that there is not a one-for-one metric equivalent to US wire sizes.  It took me a week, but I think I achieved my goal.  The end result is that it is so subtle, the casual reader won't notice I made a change.  Any new modeler visiting my site won't know notice there was ever a problem and will know which wire they need to buy.


Enjoy!


Allan Gartner

Wiring For DCC


Re: Common Metric Wire Sizes

wirefordcc
 

This is for modelers needing metric wire sizes.  I have revamped the charts for metric wires.

 For feeders, go to:  http://www.wiringfordcc.com/track_2.htm#a14

For bus wires, go to::  http://www.wiringfordcc.com/track_2.htm#a26

if you want a detailed chart of US and metric wires for general use, go to:  http://www.wiringfordcc.com/wire_sizes.pdf


This is for those that have been involved with the recent discussions of metric wire.  After our discussions earlier in the week, I continued to surf the web and think about how to present information on US and metric wire that was simple.  I didn't want the typical non-US modeler to have buy a wire gauge or a caliper to measure wire. I wanted something just as simple for the non-US modeler as it is for the US modeler.  The complicating factor is that there is not a one-for-one metric equivalent to US wire sizes.  It took me a week, but I think I achieved my goal.  The end result is that it is so subtle, the casual reader won't notice I made a change.  Any new modeler visiting my site won't know notice there was ever a problem and will know which wire they need to buy.


Enjoy!


Allan Gartner

Wiring For DCC

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