PIR Sensor analog value oscillation?

[Railroader]

@silverlock

This is another thing that I have read conflicting opinions on. In my limited experience I haven't had problems with the Arduino powering the relay board, but my experience is definitely limited. I'll re-work this.

Paul_B: Are you saying that the only acceptable ways to power an Arduino Uno are by USB or by feeding already-regulated 5VDC into the 5V pin? I don't mean to be difficult or ungrateful for the advice, but that goes against a lot of what I've read. All of the 'how to power an Uno' articles list the barrel jack and Vin as acceptable alternatives.

Almost every day some helper explains how limited the Vin to +5 onboard converter is. It's small and it has no heatsink. Many projects work for some seconds or minutes until that tiny converter is overheated and shuts down.
There's a lot of bad "advice" given by complete amateurs out there.
Rely on @Paul_B!