Yes Leo you are correct. That's the problem with composing msg.s late at night.
I tried Stan's circuit using just the digital pin (for input), and there is no delay on the decay as observed on the arduino output to the relay. When I measure just w-meter at the trigger output of the circuit , the decay to almost zero takes several sec--which is what I want. I guess maybe the digital pins toggle on transition? So now I will use my meter measurements & analog pin to toggle on levels and see how that works.
