Dynamis and reverse loops frustration

[ALCO0001]

 Hi Everyone,
Have a New Dynamis system and it may have a problem with an over sensitive short detection issue. I have tried many reverse loop modules thinking that they were the problem .
Wile entering the loop the module senses the short and reverses polarity ,problem is that the Dynamis system being so sensitive to shorts TRIPS shuts down .I have read that people are using a 21 watt car lamp wired in series between the module and track and this works ,but also puts too much load and I can barely run 2 sound engines at once ,acts like a brown out . Too much load ,sluggish performance this is not right .Customer service is looking into it,but does not seem to have a clear answer.Does anyone know if there is a real fix for this adjustment or anything  ?
Jack

[JRG1951]

Jack,

1, You can manually reverse the loop with a DPDT switch.

2. You could use 1 light sensor to trip a reversing relay if you only enter the loop in the one direction.

Regards, John

A man oughta do what he thinks is right. <> Hondo Lane - Hondo

[bapguy]

Have you tried an electronic one? My friend had a similar problem with his MRC system. I bought him a DCC Specialties on guard  AR and it solved the problem.  Joe   

[ALCO0001]

Joe ,
,I have a mrc and a Digitrax for 2 loops that work,but if you run through the loop 2 much ,too soon seems like they heat up and trip the Dynamis breaker for shutdown .Both reverse modules work a few times LIKE they should ,but then the short effect  and shut down takes hold if they are used too much too soon .I am also powering 2 digitrax stationary decoder modules for accessory operation of for my twin coil witch machines that owers the module from the rail . Think maybe too much draw ff the rail. What Brand of reverser was that ?
Jack

[bapguy]

 I replaced my Digitrax AR1 with a DCC Specialties on guard auto reverser. I installed one on my friends N scale layout as well. In the August issue of Model Railroader, the DCC column talks about a separate booster for accessory decoders. Tam Valley is the ones used in the article.    Joe

[Joe Satnik]

Dear Jack,

Just a few passing thoughts:

Do both rails have insulated rail connectors on both ends of your reversing zones?

Is your train short enough to fully fit in every zone, normal or reversing?

Hope this helps.

Sincerely,

Joe Satnik 

[ALCO0001]

Dear Joe,
Yes indeed, insulated rail joiners,and the reverse loop sections are well long enough to hold any consist .Today my first try without the bulb it shorted and shut down .

Hooked up the bulb again and it worked flawlessly,but with the sound big boy at the same time at the other end of the layout going up the grade it was sluggish to say the least .The throttle was turned up full to just make the grade .

Normally ,not even half throttle,noticed the bulb was getting very hot to the touch. I am versed in electronics somewhat ,enough to be dangerous and it seems instead of a light bulb that really loads the system , should there not be some type of capacitor to absorb the spike of the short to maybe cut back on the shut downs and still protect the system ?

Automotive electronics use these to protect there on board sensitive pc  electronics ,but with the digitial signals coming out of the cab to the rail I am not sure that it would work at all since my earlier experience with  dcc ready sd45 that I PUT on the rail for a second on a dcc rail with out a decoder and it let the smoke out of it ,melted the shell a little and basically blew up the capacitor on the circuit board and this was a spectrum from the 90s.OOPS! LIVE AND LEARN! .
Jack

[Joe Satnik]

Dear Jack,

Try a slightly higher wattage bulb or filament. 

Reverse loop rail insulators are usually near turnouts. 

Is it possible that the wheels on your locos or other rolling stock are wide enough

to short between closure or frog (opposite polarity) rails on the turnouts?

I'm thinking that small duration wheel shorts near the frog might heat up or "pre-trip" your Dynamis circuit breakers. 

Hope this helps.

Sincerely,

Joe Satnik 

[ALCO0001]

Joe,
Yes ,this is what is going on .You nailed it Thank you!.I have a dremil tool to cut something in a switch to insulate or create a isolation point or 
Jack

[Joe Satnik]

Jack,

Hold off on doing anything major here.

I'm guessing that your wheels or track are out of spec somehow, perhaps gauge.

Get an NMRA wheel and track gauge and check them,

or use a caliper to measure and compare with the specs:

http://www.nmra.org/sites/default/files/standards/sandrp/pdf/RFC_Stds_PDF/S-3.2_rfc0707.pdf

http://www.nmra.org/sites/default/files/standards/sandrp/pdf/RFC_Stds_PDF/S-4.2_%20rfc0707.pdf

Wheel "back-to-back" (B) and wheel "thickness" (N) are the easiest to measure with a caliper.

Once we know the measurements, we'll be in better shape to recommend fixes.   

Hope this helps.

Sincerely,

Joe Satnik

[ALCO0001]

Joe ,
Thanks for the hold up, Got a little jumpy.
The short in the switch is in the throws before the frog if your running through the switch when Not thrown,the track isolators come in right after  this switch  then your in the reverse loop for about 5 feet  and then I have the isolators a little uneven at the other end on a slight curve before another switch that is on the main .
I am going to replace the shorting switch  and rework /even up the isolators on the other end since I do run metal wheels on rolling stock and I will retest and let you know.
Best Regards,
Jack

[rogertra]

Joe ,
Thanks for the hold up, Got a little jumpy.
The short in the switch is in the throws before the frog

Do you mean the "points"?

Cheers

Roger T.

[jward]

to backtrack just a bit here, i noticed in one of the posts using a capacitor for short protection...... in a word, don't........dcc is a form of square wave ac, a capacitor will pass ac, and probably give you the short you are trying to avoid. capacitors work fine as filters on dc, or in cases such as a radio receiver where you want to pass the ac from section to section, but keep the dc filtered out.

this is one of the big reasons it is recommended that when you hardwire a decoder you remove any capacitors that might already be in the locomotive.

[ALCO0001]

Joe ,
Thanks for the hold up, Got a little jumpy.
The short in the switch is in the throws before the frog

Yes Sir .Have my terms mixed up Roger Thanks!


Do you mean the "points"?

Cheers

Roger T.

[ALCO0001]

Jeffrey,
Yes your correct ,having a little memory thing going on with the capacitors since I have used them with DC .
I was trying to find more of a correct part then a bulb wired in series that seems to take away too much power.I measured the resistance in the bulb I have wired in 1.6 ohms. Compared to a 1156 automotive light bulb at .6 ohms.Well there is one problem I guess I need the .6 ohm bulb since the 1.6 is too high pulling down the system power ,but that is just  theorizing for now. Ideas?

Jack