Timer Running Output

A pretty common thing people want to do is to have a signal run for a certain amount of time. For example, open a door for 3 seconds. The most intuitive gadget to reach for is the timer and set it to 3 seconds. But right now, it's pretty tricky to get a setup that can give you such a signal using the timer. It often requires more gadgets, and a deeper understanding of how the timer works etc.

The alternative is fairly simple: use a timeline, and add a switch inside it for the length of time you need. Set the timeline to "once" mode so it runs the full time. And use the switch's signal. But again, that requires more knowledge of a different gadget and how "once" playback mode works. This also means the time it runs is not as easily customisable by wire--for example a value slider as a setting in a contraption. And it uses 2 gadgets.

An even more esoteric method would be to use an instrument with a note lasting the required amount of time, in "once" playback mode, with its volume reduced to 0, modes off, and slices deleted. Then use its "is playing" output. This would do the job, and for only 1 gadget, but this requires even deeper knowledge of the engine, and is reaching even further away from what is intuitive, and easy to understand at a glance.

A simple "timer running" output from the timer would do exactly what we need, and be very obvious to newcomers how to use it, and need no extra gadgets.