AR1 failure?

[Trip]

I have an AR1 switching a reverse loop and it seems to have stopped switching. A loco entering the loop is fine but when it exits the booster detects a short and shuts down. I've had this AR1 for two years and it's worked fine until yesterday.

 

Power is still being supplied to the loop. Is it possible for a AR1 to fail this way? 

 

I have a single DB210 booster set to 5A.

[HLT 0109]

Steve,

 

I have no experience of the AR1 or the DB210 but I have several reversing loops in my layout (which is powered by NCE Procab with SB3a 5amp booster) and I did have troubles from time to time with one of my longer reversing loops.  In my case, although power was being supplied to the loop, there was a break in the supply part way round the loop - ie a bad solder joint or dirty rail joiner.  Sorting out those defects cured the problem.  A question though - you say a loco is OK entering the loop - but is that always from the same end, or does it enter satisfactorily in the opposite direction?  If it can enter the loop from either direction, then the power must be switching - suggesting the problem is not with the AR1.

 

Harold.

[Phil S]

Check both visually and with a multimeter that both rails at each end are still gapped.  Also - check that the supplies to the adjacent (non reversing) tracks at entry and exit are both still of low resistance and passed to the AR1 for comparison  (ie it may not be a fault with the AR1 itself, but one of the signals it is using to detect the need to change).

It can be easy when faultfinding a 'closed loop servo system' of some kind to only consider the basic signal path, and not all the supporting parts -such as power supplies and sensors (/timing devices where applicable) which are just as important to the correct functioning.

 

I assume you have not changed the main controller - that may have changed its cutout time which might affect an auto reverser. 

 

There are now alternatives to the 'detect a short' type of auto reverser - Massoth in G Scale (primarily) offer one to avoid a 10A short circuit current !! - but LDT do a kit for a much lower price (and current) - in which very-short sensor sections are used between the standard 3 sections - and this pre-changes the polarity of the reversing section ahead of the short circuit occurring (which would still take place and operate the auto reverser if for some reason the sensor failed to detect )

[Trip]

Thanks gents. After checking with a multimeter I swapped out the AR1 with another one on a less used part of the layout and it works fine. I've got a solid state dual frog juicer on the way to replace the other one. 

[njee20]

I had one AR1 dead on arrival, and another one inexplicably die like yours after 18 months light use.

 

I concluded that they’re just a bit fragile.