Date   
Re: Peco Electrofrog - Adding Gaps

William Teeters <cozyflyr9398@...>
 

A lot of people throw the term "gap" out there with no explanation as what they mean which, leads to a lot of misunderstanding. Is the rail being cut?. or are insulators being used?. An explanation of actually what is being done would stop a lot of confusion and cost to the person who is not wise to where the rail can actually can be cut without a disaster, such as the small rail sections falling out in a persons hand when the cut is made.. Just a thought, a lot of great information on this site. Bill Teeters Chicago,Peoria and Western RR. As seen on the RockRail.org site, Located Rockford, Ill.



From: Scott H. Haycock
To: WiringForDCC@...
Sent: Monday, March 10, 2014 8:53 AM
Subject: Re: [WiringForDCC] Peco Electrofrog - Adding Gaps

 
 

CZ wrote:
Stub ended sidings where you're feeding power from the switch point end will not require that gapping.

If the siding is only a single industry, where no locomotives will be operating, you are correct. But if it is  situation where a locomotive will be spotting cars while the turnout is aligned the other way, as in a multi-spot industry, or a short branch into an industrial park,  a condition where both rails are the same polarity (phase, in DCC) will occur, if you don't isolate the frog.
As you noted, using the concepts of DCC friendly turnout wiring is best, even if you are not using DCC, Also, I would wire (and gap) every turnout to these standards, whether necessary or not. When it comes to model railroad wiring, standardization,  consistency, and documentation  in you wiring practices will benefit you down the road, when you find yourself troubleshooting a problem!__




Scott Haycock
Modeling Tarheel country in the Land of Enchantm
ent



Re: Hot Snubber

Blayne & Anne
 

I would have unsoldered one of the cool ones a long time ago and moved it to this location. 

Re: Hot Snubber

redking56@...
 

Could it be the specific location of that particular snubber?
Rich

Re: Hot Snubber

Bob H <rehandjr@...>
 

Rich,

Sounds like something in that district is drawing current from 1 rail throught the resister to the other rail.  I would lift connections until I found which device is drawing the current.  

bob


>Since a pair of resistors came in the package, I decided to first replace the 1/2 watt resistor with a 1 >watt resistor while keeping the original capacitor.  Result: the 1 watt resistor was red hot.

Re: Hot Snubber

Flash Gordon
 

Sounds like you had a bad capacitor.... throw it and the red hot resistor away.

If you do not like the resistors being warm swap a warm pair with a cool pair and see if the heat goes with the warm pair. If it does scrap the warm pair and replace them. I have suggested this before. It is the only way to see if the warm pair are defective or you have some other problem.

Personally I do not like warm components, that is a loss/waste of current turning to heat.

Ed S

At 03:14 PM 3/14/2014, you wrote:


I made my way over to my local Radio Shack today and picked up a capacitor, 0.1 uF,250 WVDC (272-10530 and a pair of resistors, 100 ohm, 1 Watt (271-152).

Since a pair of resistors came in the package, I decided to first replace the 1/2 watt resistor with a 1 watt resistor while keeping the original capacitor. Result: the 1 watt resistor was red hot.

So, I soldered the other 1 watt resistor to the new capacitor and soldered it in place of the older assembly. The resistor was very warm but not hot so that I could hold onto it between my fingers.

In both cases, the capacitor was cool to the touch.

I went along my layout and examined the other snubbers. All of the capacitors were cool. Some of the resistors were cool, some were warm, none was hot.

Thoughts?

Rich

Re: Hot Snubber

Charlie Sleep <csleep@...>
 


I am the last person to ask regarding anything electronic. Having said that, it seems to me that a resistor would have to be conducting current to get warm and a capacitor is supposed to block DC current. Is the snubber actually passing enough AC through the network to produce current fluctuations strong enough to heat the resistor?
 
Thanks for clarifying my ignorance.
 
Charlie Sleep

Re: Hot Snubber

redking56@...
 

I made my way over to my local Radio Shack today and picked up a capacitor, 0.1 uF,250 WVDC (272-10530 and a pair of resistors, 100 ohm, 1 Watt (271-152).

Since a pair of resistors came in the package, I decided to first replace the 1/2 watt resistor with a 1 watt resistor while keeping the original capacitor.  Result: the 1 watt resistor was red hot.

So, I soldered the other 1 watt resistor to the new capacitor and soldered it in place of the older assembly. The resistor was very warm but not hot so that I could hold onto it between my fingers.

In both cases, the capacitor was cool to the touch.

I went along my layout and examined the other snubbers.  All of the capacitors were cool.  Some of the resistors were cool, some were warm, none was hot.

Thoughts?

Rich



Re: loading a booster for performance and thermal testing

Phil Euper <peuper@...>
 

Agree Ed.......Len, why not look at the output of the command station then put this output thru
the booster you built and look at it's output and compare the two outputs. If they
are same or close to the same you should have a successful build!

Regards

Phil Euper in SC

-----Original Message-----
From: Ed S
Sent: Wednesday, March 12, 2014 7:08 PM
To: WiringForDCC@...
Subject: Re: [WiringForDCC] loading a booster for performance and thermal testing

Len

I do not understand why you would test it with out sending DCC
packets. Isn't that the point?

Ed S

At 06:53 PM 3/12/2014, you wrote:


Thanks Mark,

MERG UK has some pretty neat stuff as kits for very reasonable cost.
Membership is needed but cheap. The boosters are $45 for a complete
kit and I've verified that NCE users have them and work well. I
haven't looked into the front end as to the driver chip and DCC
packet protocol, but it just dawned on me I can bypass that and test
the power output section. That's where the smoke and heat is.

I always look for a sanity check!

Len Jaskiewicz



------------------------------------

http://www.WiringForDCC.comYahoo Groups Links

Re: loading a booster for performance and thermal testing

Flash Gordon
 

Thanks Len..

Yep eliminate variables.... continue and report.

Ed S

At 07:50 PM 3/12/2014, you wrote:



Len

I do not understand why you would test it with out sending DCC
packets. Isn't that the point?

Ed S
Ed,

DCC packets is not the primary point of testing!

The booster is a power device. The main output is a H-bridge configuration, typical of motor controllers. It has to first be established that the power section is functioning as designed and at full power and there are no thermal issues with the switching devices. The testing should also include transient overloads to verify protection circuitry(I have over 30 yrs experience in switching power design).

Hope this helps your understanding as well as others.

Len Jaskiewicz

Re: loading a booster for performance and thermal testing

jazzmanlj
 


Len

I do not understand why you would test it with out sending DCC
packets. Isn't that the point?

Ed S
Ed,

DCC packets is not the primary point of testing!

The booster is a power device. The main output is a H-bridge configuration, typical of motor controllers. It has to first  be established that the power section is functioning as designed and at full power and there are no thermal issues with the switching devices. The testing should also include transient overloads to verify protection circuitry(I have over 30 yrs experience in switching power design).

Hope this helps your understanding as well as others.

Len Jaskiewicz

 

 

 

Re: loading a booster for performance and thermal testing

Flash Gordon
 

Len

I do not understand why you would test it with out sending DCC packets. Isn't that the point?

Ed S

At 06:53 PM 3/12/2014, you wrote:


Thanks Mark,

MERG UK has some pretty neat stuff as kits for very reasonable cost. Membership is needed but cheap. The boosters are $45 for a complete kit and I've verified that NCE users have them and work well. I haven't looked into the front end as to the driver chip and DCC packet protocol, but it just dawned on me I can bypass that and test the power output section. That's where the smoke and heat is.

I always look for a sanity check!

Len Jaskiewicz

Re: Garden layouts/Booster Protective Housing

jazzmanlj
 

Thanks Allan,

Kind of makes me wonder on some of these massive layouts out west how they approach the cooling.

I'm in Mass so it's not so bad. I'll do worst case testing before making decisions.

 

Len Jaskiewicz

Re: loading a booster for performance and thermal testing

jazzmanlj
 

Thanks Mark,

MERG UK has some pretty neat stuff as kits for very reasonable cost. Membership is needed but cheap. The boosters are $45 for a complete kit and I've verified that NCE users have them and work well. I haven't looked into the front end as to the driver chip and DCC packet protocol, but it just dawned on me I can bypass that and test the power output section. That's where the smoke and heat is.

I always look for a sanity check!

Len Jaskiewicz

Re: loading a booster for performance and thermal testing

Mark Gurries
 

On Mar 12, 2014, at 3:06 PM, <len.jask@...> <len.jask@...> wrote:

I'll be building MERG boosters soon set up as 10A units. My thought is to drive it with a 8-10kHz square wave as opposed to a command station and use pure resistive load. This way I should be able to probe around and verify most waveforms and a good balance in the output drivers.

Any thoughts or comments on this approach appreciated.

Len Jaskiewicz
That would be a good test if it worked.

I do not know anything about this MERG boosters to know if it will work or not. So Boosters might look for a DCC packet protocol. Do not know. I know no harm will come of it if you try.

Best Regards,

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

loading a booster for performance and thermal testing

jazzmanlj
 

I'll be building MERG boosters soon set up as 10A units. My thought is to drive it with a 8-10kHz square wave as opposed to a command station and use pure resistive load. This way I should be able to probe around and verify most waveforms and a good balance in the output drivers.

Any thoughts or comments on this approach appreciated.

Len Jaskiewicz

Re: Garden layouts/Booster Protective Housing

john
 

Weather proof wiring is easy but a little expensive. You can use Type UF wire and make your splices in underground, grease filled splice packs from your local electrical supply. If the distances are not too long or too many, multiple runs are better than splices. Mounting electronics out doors is tedious and expensive, while running a number of wires can be reasonable. Track connections are important out doors, I found that mechanical clamps are and excellent value.
enjoy.
john

From: "bigboy@..."
To: WiringForDCC@...
Sent: Tuesday, March 11, 2014 10:57 PM
Subject: [WiringForDCC] Re: Garden layouts/Booster Protective Housing



I debated whether to put the boosters in waterproof housings and try to run network cable through the garden or mount everything in the garage.  I opted to put everything in the garage.  As it turned out, the Texas summers are so hot, that I needed to add fans to my wall mounted boosters.  If I had tried to mount them in waterproof housings in the sun, I surely would have been in trouble. 

Allan





Re: Garden layouts/Booster Protective Housing

wirefordcc
 

I debated whether to put the boosters in waterproof housings and try to run network cable through the garden or mount everything in the garage.  I opted to put everything in the garage.  As it turned out, the Texas summers are so hot, that I needed to add fans to my wall mounted boosters.  If I had tried to mount them in waterproof housings in the sun, I surely would have been in trouble. 


Allan


Re: Hot Snubber

redking56@...
 

Will do.
My local Radio Shack has the capacitor and a 1 watt resistor.
I will report back with the results.

Re: Snubgber or Terminator or what?

Mark Gurries
 

Well I say your one if not the FIRST person I have know that have even tried a scientific method of analyzing the problem.  Clearly not anecdotal engineering.  Most people by far just say throw out the comments they have no problem without being able to refer to any test or describe what they are even looking for.

I used a DCC packet analyzer from PriCom.  Most people do not even know about this device nor understand what it doing or how to use it.


I setup various test with no locomotive running and with many running on a set path on a club size layout with 50 foot track bus run used as my test run.  I based line at the booster with a accumulative run of DCC packets error over the limit of the run of the locomotive. I repeated the test.  I then move to the end of the track bus and repeated the test.  The results were worse with locomotive running and being located at the end bus.  By using a relative measurement, I have taken the analyzer accuracy or errors out of the equation.

I then repeated the test with a RC filter installed at the end of the track bus and got better results.   I did this about 10 years ago or so when the analyzer first came out.

What got me started down this path was a weird problem I encountered with a large loop of track (60 feet or so) of a modular HO layout and the LENZ decoder which had a DCC conformance warrent. The layout wiring and track was in a closed conductive 360 loop.  No breaks in the track (no insulated rail joiners or gaps) and no breaks in the wiring.  I could run the engine around the loop without a problem in any direction.   Pick the locomotive up, rotate 180 degree put it back down on the same track and I had no control.  Flip it back and got control back.  Very consistent results.   Move this same locomotive to another part of the layout and it worked fine no matter what I did.  Went back to the physical location where I observed the problem, and the problem came back.  I remember wishing that someone from the NMRA was here to see this.   

Taking notice of where I was, the location was the farthest from the booster.  Thinking transmission lines, reflections and voltage spike chaos, I solved the problem two ways.

1) Broke the loop at this point, installed insulated rail joiners and disconnected the track bus connector that goes between module to module.

2) I experimenting with a load resistor placed where I had the problem with no changes to the original wiring.   

With one or the other solution, the locomotive now worked just fine.  This is what drove me to develop the RC filter and splitting the track bus up recommendations (no wiring loops).  

The cap simply reduced the average current to allow the resistor to run cooler but allowed the resistor to still attack any high dV/dt or noise.  In other words it attacks any noise created by the wire inductance interacting with the random wheel to rail contact (changed in current) and resulting voltage spike due to the nature of small shorts especially around turnouts.   Any oscilloscope can clearly capture this if you set it up correctly.  

We even have some photos of wire inductance effects here:


More regarding the effectiveness of the RC filter on voltage spike can be found here:


There was a test of the RC filters effectiveness in the NMRA scale rails publication too.

Clearly the decoder was sensitive to the wiring.  When I used any other engine with a different decoder, I had no problems.  So It was just happenstance that I discovered this problem.  I was not expecting any problems.

The NMRA decoder conformance test setup does not account for any wiring variable nor random noise in the form a real world wheel to rail contact when doing the conformance testing   

I recognized the decoder decoder DCC packets differently.  Decoders can be difference in both hardware (filtering) and software decoding methods or assumptions   Just like a decoder, I cannot say if Pricom method of decoding DCC packets is worse or better than anyone else's method including yours.   Clearly differently design equipment will get some variation in test results.  We would need to have a head to head comparison of the two measurement devices directly to investigate that variable.

What I do know that many people on this list over the past 10 years or so have followed these guidelines and solve problems they did not know how to solve.  I even have DCC manufactures following these recommendations and putting them in the manuals.  The results speak for themselves.




On Mar 11, 2014, at 4:15 PM, <aaronmorley@...> wrote:



Mark,

How do *I* even test for that? I built myself a packet reading device, it listens in on the control bus and the system track bus output, it then compares the information it receives at a listening input down the track bus. Every so often I shift the locations of the track and control listening points. It highlights differences between control input and system track output, and differences between the system track output and what it hears further down the track. I basically get a text file with every data transmission recorded in it and the differences are highlighted by bolded text, a typical day's operating results in thousands of commands being read, I think the record at an exhibition was 63,000+ entries in the text file, bolded lines were so negligible.

My 'anecdotal engineering' tells me that well under 2% of packets are erroneous! it's probably a whole lot less than 1%, but I am not going to claim that level of accuracy. Some of those corrupted packets are corrupt exiting the system, that is the wiring still conveys the garbage data. Corrupt packets sent on the control bus are very rare, and these are not typically sent out on the track, those that are would be rejected by good decoders anyway.

Packets that go corrupt between the system and the track are similarly rare, they could be attributable to track/wiring inductance or capacitance, external radiation etc, or even be present due to switching errors in the booster, the reality is, fitting a snubber may not even help and is certainly not necessary.

Aaron.


---In WiringForDCC@..., wrote :


On Mar 10, 2014, at 6:52 PM, <aaronmorley@...> <aaronmorley@...> wrote:


There would be less confusion surrounding snubbers if it were simply recommended that they only be used in situations where there are problems related to the DCC communication.

It not limited to just communication problems.

How do a typical person or even you go about determining that?   
 
My club's layout features multiple control bus paths one exceeding 150' several others of significant length (50'+) each with multiple star points and hence end points without a snubber in sight. No loss of control or other communication issues noted in years, not a runaway on record and 99% of the locos would not have DC operation disabled by CV 29.

Understood but these statement fall into what is called Anecdotal Engineering based on visual observation.


If you do not know exactly what your looking for, how can you say you do not have any problems?  There are many layout smaller than your that DO have problems. 

Best Regards,

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






Best Regards,

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



Re: Hot Snubber

jazzmanlj
 

Replace it.

Hot cap /cooler resistor then cooler cap/hot resistor? Not making sense so change as Mark suggests. Use a 1W resistor if possible. Then see how it runs. Process of elimination!

Keep the group posted as to results.

Len Jaskiewicz

 

Mark, the use of the word "hot" is indeed subjective. So, let me put it this way. When I touched the capacitor last week (not the legs but the body of the capacitor), I could not grasp it for more than a quick touch without risking burning my fingers. The resistor was very warm but not hot enough to burn my finger. Today, the capacitor was cool to the touch, but the resistor was as hot today as the capacitor was last week.

Rich


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

Hot is subjective.

Normally the capacitor is ALWAYS cool in the sense it does not generate any heat. The resistor is the only device that should get warm assuming there is nothing wrong with the capacitor. Given the very close proximity of the resistor to the capacitor, it will heat up the capacitor via the wire leg connection between the two. But it should always be cooler than the resistor.

If you believe the RC filter is inconsistent in performance, then simply replace it with a new one and throw the old one out. A defective capacitor is a possibility. Replacement is a very inexpensive and an excellent way to quickly address all the variables with the old filter.