Basically as the title says. We have semi frequent power outages where I live. The noise machine in my daughter’s room goes out and wakes her up. If I were to buy a USB powered one, plug it into a power bank like one of those 10000ma ones you get for charging cell phones, would it have continuous power. Basically like a cheap UPS
I was gonna suggest a regular UPS (some have USB ports), but OP said it was for a noise machine/sleeping, so didn’t want to recommend something that would start beeping randomly lol.
Some you can access via the Ethernet and change the settings. Got one of those units and then see if it has the option.
Here’s just one tutorial: https://linux-tips.com/t/disabling-ups-beep-under-linux/592
There are many others. Good in places where medical equipment keeps you alive and sleeping.
Yea I’ve got some Cyberpower UPSs for bigger equipment but it seemed like overkill to add a $100 battery to a $20 noise machine. Plus they’re actually pretty noisy on battery mode (they buzz)