Stayin' Alive

We're still learners when it comes to this DCC malarkey, and every day is a school day.

Take my favourite loco in the Minffordd fleet, the Simplex Mary Ann for example.

When it was re-motored and chipped for its new digital life we managed to squeeze in a stay alive capacitor which was so effective the loco would continue to run for around 10 seconds after it was picked up off the track.

When he was giving the stock a once-over ready for the trip to Porthmadog last week Himself noticed the stay alive didn't appear to be functioning.

We hadn't noticed any particular problem with the loco at the show in Glasgow.

As usual it was superbly reliable and most problems seemed to be caused by route-setting errors resulting in short circuits. 

We did notice some of the other operators giving it a prod every now and then, but assumed that was just operator error.

It was after a while of puzzling that Himself discovered there is a CV setting on these chips which controls how long the stay alive supplies juice for, and adjusting that restored the function.

It was then that the penny dropped.

Towards the end of the first day at the Falkirk show last year Mary Ann developed a strange fault where all the DCC sounds played but there was no drive.

The solution was to reset the decoder - but we made a bit of a beginner's error!

We thought we had moved every other DCC loco to safety by taking them all to the upper fiddle yard and disconnecting the power supply.

We punched the buttons on the handset to reset Mary Ann and it sprung back to life!

And shortly after, every other one of our 009 steam engines began hissing in unison. 

They had all been reset, too!!

But how? We had disconnected the power supply to the fiddle yard!

It transpired that the joints between the scenic board and the yard were close enough that the rails in the yard were still getting some power.

So that was a fun 15 minutes resetting the numbers on every loco in turn....

It's only now we think back to this incident that we realise the CV to control the stay alive must have been reset to 0 in this process.

So much to learn...