When a command block outputs true it remain true until it is activated again and doesn't meet the requirements

I attached a comparator to a command block and set the command "scoreboard players remove @p[score_Gold_min=20] Gold 20", obviously if it meets the requirements it will output a signal strength of 1. The problem is it will stay so until I activate it again when I don't meet the requirements, so then it can turn off.

I'm not sure if it is a bug, but I wish it would output a signal for a short while so you can reactivate it with a button. I want to be told though if it is a bug or intended feature for now.