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!

A LION with a GREMLIN (not the car)

491 views
7 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    July 2006
  • From: North Dakota
  • 8,460 posts
A LION with a GREMLIN (not the car)
Posted by BroadwayLion on Monday, February 10, 2020 10:40 AM

LION  went up to train room.

Him had to chase an electric gremlin.

There is a short between the +16v dc circuit (signals and relays) and the +~v dc Third Rail circuit (Track Power)

I have unplugged the 16v transformer and I tested between ground and the 16v bus.

Test 1 Yes voltage was present.

Test 2 20' down the bus, I cut the bus wire, 0v to the left 12v to the right, I repaired the cut

Test 3 andother 20 feet down the bus. Same result

Test 4 another 10' down the bus bus ends and is jummpped over to the second table. Table 1 = 0v; Table 2 = 12 v

At this point work stopped: it was time to go to vespers. I will need a mirror to look behing the facias to see what is there before I move to table 2 to continue my search.

 

Well at least I do not have to search wire by wire for the issue.

ROAR

PS: Make special note to the LION: tip of soldering iron is grounded. Using it on live circuits is a good way to blow out fuses.

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

  • Member since
    January 2004
  • From: Canada, eh?
  • 10,201 posts
Posted by doctorwayne on Monday, February 10, 2020 1:20 PM

BroadwayLion
PS: Make special note to the LION: tip of soldering iron is grounded. Using it on live circuits is a good way to blow out fuses.

Did discovering this fact give you pause?  Or did it singe your paws?

Wayne

  • Member since
    July 2006
  • From: North Dakota
  • 8,460 posts
Posted by BroadwayLion on Monday, February 10, 2020 1:31 PM

I *knew* this but forgot about it. I kept hearing a little snick as I touched the wire, and then the currants all dribbled away. : )

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

  • Member since
    February 2002
  • From: Reading, PA
  • 27,321 posts
Posted by rrinker on Monday, February 10, 2020 1:42 PM

 Faster way to divide and conquer, since electrons are not like wildebeests and there won't be a slow one trailing the herd to make an easy grab for the lion:

 First cut in the middle. Now you know which half of the layout has the short. Second cut, midway between the first cut and whichever end showed the short. Now you know which quarter of the layout has the short. Next one in the midpoint of that section, until you have a managable section left.

Beats starting at one end and working along. You can still switch to this - since you know everything is good up to the last point you checked, now you can check midway between the end and the last point you tested. ANd if the issue is one wire from bus A touching a wire from bus B that it shouldn't, you can keep the power off and just test with continuity mode. Paws off the third rail.

                                  --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
    June 2014
  • From: East Central Florida
  • 448 posts
Posted by Onewolf on Wednesday, February 12, 2020 7:15 AM

rrinker

 Faster way to divide and conquer, since electrons are not like wildebeests and there won't be a slow one trailing the herd to make an easy grab for the lion:

 First cut in the middle. Now you know which half of the layout has the short. Second cut, midway between the first cut and whichever end showed the short. Now you know which quarter of the layout has the short. Next one in the midpoint of that section, until you have a managable section left.

Beats starting at one end and working along. You can still switch to this - since you know everything is good up to the last point you checked, now you can check midway between the end and the last point you tested. ANd if the issue is one wire from bus A touching a wire from bus B that it shouldn't, you can keep the power off and just test with continuity mode. Paws off the third rail.

                                  --Randy

 

Ah, the old bisection method of short discovery (or root finding)....

Modeling an HO gauge freelance version of the Union Pacific Oregon Short Line and the Utah Railway around 1957 in a world where Pirates from the Great Salt Lake founded Ogden, UT.

- Photo album of layout construction -

  • Member since
    May 2010
  • 6,389 posts
Posted by mbinsewi on Wednesday, February 12, 2020 8:00 AM

I don't think Julius Cesar had a model railroad, but if he did, and an electrical problem accured, I'm sure he would resort to his "divide and conquer" approach.

Mike.

  • Member since
    February 2008
  • 6,828 posts
Posted by maxman on Wednesday, February 12, 2020 9:14 AM

mbinsewi

I don't think Julius Cesar had a model railroad, but if he did, and an electrical problem accured, I'm sure he would resort to his "divide and conquer" approach.

Mike.

If ole Julius had a problem he’d probably just throw it to the lions.  Oh, wait a minute, that’s where all this started.

  • Member since
    July 2006
  • From: west coast
  • 4,895 posts
Posted by rrebell on Wednesday, February 12, 2020 10:31 AM

I have found that if you look for the stupitest thing you could have done, that is ussually where thebproblem lies.

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!