Re: Genossen, wir mussen alles wissen!
I have a very smart doorbell.
It only sounds for a fixed period, regardless of whether you stab the button or hold it in. It has an indicator (LED) to show it's active that goes out once you've pressed the button, and a fixed time before it will reactivate. Oh, and that fixed time starts from when you release the button.
As you can imagine, it's a very complicated controller... using two transistors and one CMOS chip.