Problem with Dallee Trak-dt occupancy detectors

[B&Mbarn]

 

I've installed 4 Dallee Trak-dt occupancy detectors over the last several months. After initially working fine for a couple of weeks, two have developed the problem of not clearing when a train leaves the controlled section. Removing the track power supply wire from the sensor still does not result in the signaled section becoming deactivated.  The only way I can clear the detector is to cut power to the detector for at least 10 seconds.  When power is restored the detector deactivates and the signal clears.  I have tested both problem detectors on a 3' section of track mounted on a board to eliminate any possible  problems generated by the layout.  They still fail to clear.  Anyone else had this problem with Dallee detectors?  The other 2 detectors have continued to work fine.

[MisterBeasley]

Have you tried contacting Dallee on this?  It sounds like you've got a problem with the circuit.  It's not likely to be the detector.

[retsignalmtr]

i don't have my instructions for the dallee detectors handy but i remember reading about a trim potentiometer that adjusts the units sensitivity. you may have to adjust it to desensitize it a little. i've got three detectors in use for about 8 months now and they work good. very sensitive for n scale as they trip as soon as one wheel of a loco spans the insulated gap.  if this doesn't work call dallee. they may be under warrantee.

[B&Mbarn]

 

Thanks for your suggestions.  I have talked with Dallee a couple of times. Unfortunately, their recommended fixes have not worked.  I have rotated all 4 detectors through all four signaled sections on my layout and through the 3' test track I set up.  The "good" detectors work in all settings and the "bad" detectors work in none, which leads me to believe the circuit is not the problem.  I am getting full power (16.5v) from the AC source and full power (12V) out of the regulated DC power supply.  I think I may need to send them back and let Dallee test them.

[MisterBeasley]

Given the rotation test results, I would agree that you've got bad detectors.

Thanks for coming back to give us the update.  Keep us informed.  It's always nice to get that final data point on a problem.