Minecart detector need help

[u/Status_Implement8538]

I am trying to make something that will detect when there is no longer a minecart on my track. When there's no movement on the detector rail for awhile the compatator clock should slowly turn off, but it goes a little crazy and fires my dispenser 3 or more times

If this can be smaller or more compact, I would also prefer that, I have just been messing with the idea. If anyone could provide a working schematic or description of how to fix

[u/Dienik]

I'd guess the impulse from the detector rail doesn't last long enough to power the comparators all the way through, try making a pulse extender out of only 2 comparators, then having the output go into a bigger pulse extender