I am triggering a current source for a coil. I made a safety circuit with a bistable multivibrator, which forces the trigger sent to the hardware to have some maximum duration. This is a duty-cycle protection for the coil, to avoid it reaching high temperatures. So, even if the user leaves the trigger on HIGH for too long, the duty-cycle protection box makes sure the hardware does not stay on for that long (I also have a second multivibrator that makes sure cannot turn the coil back on before a certain set time but that's not needed here).
I would like to add a warning light to let the user know that the trigger they sent was ON for too long, and the safety box had to switch it off.
A simple way could be adding an exclusive OR gate that compares the user-trigger and the hardware-trigger, so that the output is HIGH only when the two triggers are different. This HIGH drives an LED which gives me a warning:
Problem: I am guessing the LED will be turned on even during the "propagation delay" interval shown in my first diagram, where the two triggers are different. I know it might be for a split second, but I want to add a D flip flop with a reset button to this circuit so that the LED stays on until the user notices it and pushes the reset button.
How can I only make my circuit "not care" about the difference between the triggers due to the propagation delay?