Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Light Bulb Short circuit protection for a Digitrax Zephyr Help!

6811 views
12 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    December 2008
  • 22 posts
Light Bulb Short circuit protection for a Digitrax Zephyr Help!
Posted by Thunder Wolf on Wednesday, June 15, 2011 9:18 AM

I Want to setup a cheap way to provide a way to see were the shorts are with light bulbs and switches (the switches are for turning the sections with the short off).  But I can't find a good light bulb that will work for a Digitrax Zephyr DCS50 HO scale layout (the system is the 2.5 amp. version) that lets me run 3 or more sound locomotives.  I tried the 1156 light bulbs and the DCS50 still sees a short; so does any one know what light bulb will work for me?

 

Thanks!!

  • Member since
    January 2008
  • From: Central Georgia
  • 921 posts
Posted by Johnnny_reb on Wednesday, June 15, 2011 10:09 AM

The light bulb circuit does not stop the short. It's showing you that the circuit is drawing enough amps to make the light glow when you run the Loco's with sound. Try running a non-sound Loco. The light circuit is meant to be used to show you what section is drawing too much power or current. If the system safety is not tripping you should be fine. Again the 1156 bulb circuit is only used to show which section is drawing enough power or current to make it glow it does not stop or prevent shorts. It only show when the power draw is high or you have a short. But in your case it's the sound Loco's drawing more power.

Try running a logo around at very low speed. Does the bulb glow at all? Now turn up the power. You should see the bulb start to glow. Sound Loco's draw a little more power in order for the sound to work. There is nothing wrong with the bulb or your system other then sound Loco's draw a little more power.

Johnnny_reb Once a word is spoken it can not be unspoken!

My Train Page   My Photobucket Page   My YouTube Channel

  • Member since
    February 2008
  • 8,878 posts
Posted by maxman on Wednesday, June 15, 2011 10:35 AM

Thunder Wolf

I Want to setup a cheap way to provide a way to see were the shorts are with light bulbs and switches (the switches are for turning the sections with the short off).  But I can't find a good light bulb that will work for a Digitrax Zephyr DCS50 HO scale layout (the system is the 2.5 amp. version) that lets me run 3 or more sound locomotives.  I tried the 1156 light bulbs and the DCS50 still sees a short; so does any one know what light bulb will work for me?

 

Tried the bulb thing and didn't like it.

But take a look at the following link: http://siskiyou-railfan.net/e107_plugins/forum/forum_viewtopic.php?3026

I would think that the internal breaker of the Zepher would be set at a value a little lower than 2.5 amps.  According to the link the 1156 bulb will limit current to 2.1 amps.  This might be high than the Zepher breaker.  The next bulb up the list is an 1142 with a 1.5 amp limit.  Maybe this would work.

What I don't like about the bulb idea is that there is always current going through the bulb even though there might not be enough to cause the filimant to glow.  So, if you were to maybe consist your three locos and run them through the section "protected" by the bulb, there might be enough current to light the bulb, which means that there will be that much less current available to power the locos, which means that you will see a speed drop.  My opinion is that the bulbs might have been a good idea up until the point where they invented the appropriate breakers.

But read over the link info, try the 1142 bulb, and let us know what happens.

Regards 

  • Member since
    January 2007
  • From: Eastern Shore Virginia
  • 3,290 posts
Posted by gandydancer19 on Wednesday, June 15, 2011 10:37 AM

Are you sure you have it wired the correct way?  The bulb should be wired in series with the track, and not across it.  (Between one rail's output connection from the booster / command station, and the rail of the track.)

Elmer.

The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.

(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Wednesday, June 15, 2011 5:24 PM

 And now you see why I DON'T like bulbs. The 1156 bulb allows about 2.1 amps to flow. Plus whatever's in the short if it's not a dead short, like a clip lead across the rails. The bulb also reacts slower than the circuit breaker in the Zephyr. So the Zephyr will still see a short. NCE has a 'breaker' using lower current light bulbs that works with the PowerCab, this will work with the Zephyr as well. The problem with breaking up an already low power output into even lesser power sections is that these sections will now handle no more than 1, maybe 2 locos, depending on if they have sound or not.

Better: fix the problems that cause the shorts, and you won't have to worry about one person with a train over in the industrial area stopping the one running out on the main.

               --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    December 2001
  • 1,932 posts
Posted by Stevert on Thursday, June 16, 2011 2:03 PM

rrinker
And now you see why I DON'T like bulbs. The 1156 bulb allows about 2.1 amps to flow. Plus whatever's in the short if it's not a dead short, like a clip lead across the rails.

I agree with Randy's line of thinking on this.  2.1 amps @ 12v is about 25 watts of power that's going to be dissipated.  I use a 15 watt pencil to solder decoders, and that's more than enough to melt a truck frame or loco shell, so you know 25 watts can melt something.

rrinker
Better: fix the problems that cause the shorts, and you won't have to worry about one person with a train over in the industrial area stopping the one running out on the main.

Right!  Fix the real problem, don't just put a band-aid on it.

  • Member since
    January 2001
  • From: SE Minnesota
  • 6,847 posts
Posted by jrbernier on Thursday, June 16, 2011 3:46 PM

  This problem happens with most of the small DCC systems.  The 2+ amps it takes to 'light' the bulb takes some time - and the Systems circuit breaker is much faster at detecting the short.  The small bulb may help, but the system may still shut down faster than the bulb can heat up and limit the current draw.

  What you need is a fast acting 'solid state' solution that will trip immediately at lower current values.  Some of these solutions can be set to trip at current drain lower than the Zephyr's 2.5 amp capacity.  You also can set a CV in the command station to trip at a 'slower' rate, IIRC.  At our club we are using Digitrax PM42 power district units.  We have them set to be very  sensitive and trip at the fastest setting.  We have the DCS200/DB200 units set to trip at the slowest settings - This combination gives us the best protection.  The power district  that the engine terminal is in was always tripping as there were so many sound /DCC engines parked there - we had to split up the tracks and separate the yard from the engine terminal!

Jim

Modeling BNSF  and Milwaukee Road in SW Wisconsin

  • Member since
    January 2008
  • From: Central Georgia
  • 921 posts
Posted by Johnnny_reb on Monday, June 20, 2011 9:11 PM

It does sound like you may need to up your system amperage a little. Sound locomotives draw more amperage then no-sound units do. Or just run 1 or 2 instead of 3 sound Locos.

When I do go to DCC I plan to install fuses in-line on the main power feed from the control unit. A glass fuse just below the trip amperage of the control unit should do it. If needed a fast acting fuse can be used.

If I remember right, the 1156 bulb was used to spot the zone that had the short. NOT protection from having one. (It's like your little brother telling on you. Here he is, he did it.) With a LARGE (club) layout some people like to run multiple power districts 10, 20 or more power zones. So with a few 100 feet of track to trouble shot. It makes it easier to be able to tell the zone you need to check rather then to have to check the whole layout. And in an operating session with 5 to 10 operators using the system at the same time, the 1156 bulb gives the power going to the short something to do other then burn something up. It lights the bulb showing you the zone that is having the problem. Letting you turn off that zone while the rest of the layout goes on as nothing has happened.

So as my layout will be on the smallish side (under 100sq. ft.), I think I'll just add a glass fuse in-line with the main power feed from the control center to the power hub. Before it goes out to the power feeds (1 to 5 power zones) and be done with it.

For a system with a trip of 2.5 amps, I would start off with a 2.0 amp fuse. If that does not stand up to the normal power usage. Try a 3.0 amp fuse. If the system trips before the fuse blows, check to see what is drawing that much power that you are normally running on your system. You may need to bump up the power on your system. But a fuse 1/2 amp over the system trip point should protect the system allowing the circuit breaker to work to do it's job. But act as a safety if it does not.

NOTE: A slow acting fuse may be needed. As a fast acting fuse may be to fast for your needs. But I will use some kind of short detection. Even if I never have a basement full of trains.

Johnnny_reb Once a word is spoken it can not be unspoken!

My Train Page   My Photobucket Page   My YouTube Channel

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Monday, June 20, 2011 9:50 PM

 DOn;t use fuses, it'sa huge pain in the rear end when one blows. Use a self-resetting electronic circuit breaker, there are many. Or check this much better light bulb alternative from Dick Bronson:

http://www.rr-cirkits.com/Notebook/short.html

This still will not work with a 2.5 amp system, for for a 5 or more amp system it will work and limits constant current throught he short to about .4 amps after the PTC opens. And it's only slightly more expensive thant he light bulbs themselves - those PTC's are super cheap.

I still say use a proper electronic circuit breaker for best results. Dick's method for a cheaper alternative, just light bulbs with nothing extra - just say no.

                       --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    December 2008
  • 22 posts
Posted by Thunder Wolf on Wednesday, July 20, 2011 10:19 PM

I found that the 1156 light bulbs that I was using were not normal 1156 light bulbs.  I found some normal 1156 bulbs and they work very well!

 

Thanks everyone!!

  • Member since
    July 2006
  • From: Pittsburgh, PA
  • 1,796 posts
Posted by JoeinPA on Thursday, July 21, 2011 9:25 AM

I thought that all 1156 bulbs were the same. What's the difference?

Joe

  • Member since
    June 2004
  • From: Orig: Tyler Texas. Lived in seven countries, now live in Sundown, Louisiana
  • 25,640 posts
Posted by jeffrey-wimberly on Thursday, July 21, 2011 10:54 AM

JoeinPA

I thought that all 1156 bulbs were the same. What's the difference?

Joe

Please enlighten us poor unworthy unknowledgeable ones.Clown

Running Bear, Sundown, Louisiana
          Joined June, 2004

Dr. Frankendiesel aka Scott Running Bear
Space Mouse for president!
15 year veteran fire fighter
Collector of Apple //e's
Running Bear Enterprises
History Channel Club life member.
beatus homo qui invenit sapientiam


  • Member since
    December 2008
  • 22 posts
Posted by Thunder Wolf on Thursday, August 4, 2011 5:06 PM

The light Bulbs That I was using they were not normal 1156 light bulbs. I took a closer look at the packaging; one says it is a heavy duty 1156 light bulb and the other says it is a 1156Lr light bulb.  The new ones I have just say 1156 light bulb.

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Users Online

There are no community member online

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!