Monday, November 29, 2010

Wots up 'err then?

The weekends job continued on the Sabbath (I can't remember seeing anything about model railways in teh bible, so it must be OK). I did a final check on one of the sections just to make sure if I had gaped everything before the paint went on. Everything checked out except one of the brass sleepers between modules, and it was not a full short, just a partial one(ie the meter doesn't flick all the way over). I managed to isolate the piece of track. still there. I re cut the slit in the middle of the brass sleeper. Shorts still there, but a bit less. widen the gaps in all the PCB sleepers. short almost gone but I'm still getting a tweak in the needle. OK, cut a bigger gap out of the brass bar.
Needle still giving a tiny tweak. Bugger

At this point I decided to connect up the DCC box, and check out if there actually is a short, or is it just my imagination. OK, so it makes a funny sound when I short it out no purpose,. Now connect it to the track and.....its fine.
Must be time for a beer. And maybe I should consider investing in a new meter?


'It must be OK, its official and everything!'

2 comments:

Anonymous said...

Love the Avo Minor meter..it would be worth a bit now on TradeMe to a collector of old electrical items!

What ohm range did you have the meter on? If on "high ohms", I would expect there to be leakage (thousands of ohms) if there were a lot of PCB sleepers (with gaps) used. This would be the leakage across the cut gap in the PCB insulating material (usually a phenolic or bakelite compound)
However, the "Low ohms" range should show an open circuit or infinite ohms.

Am Fet said...

See? It wasnt a cheap birthday present after all....

"Soaksi" (Spanish): "Yes Sir, you are definitely wet..."