You can determine your NUC;'s family from your Serial Number. The third and fourth characters in the Serial Number indicate the family of the NUC. This, it identifies that you have a BN NUC.
The BN NUCs ship with a 65W power supply. There are *many* compatible power supplies available through Amazon and most are in the US$12 - US$20 price range..
The 7th gen series use a standard 19V 65W power supply with a 5.5mm x 2.5mm barrel connector.
While there are plenty of compatible power supplies available on Amazon or eBay cheaply, the important things to watch for are:
- Voltage: must be 19V
- Wattage: must be equal or greater than 65W (or amperage equal or greater than 3.42A, because volts * amps = watts)
- Connector must be 5.5mm x 2.5mm -- this is important, as there are a fair number of supplies with 5.5x2.1 connectors but those won't fit
Honestly you can just omit the wattage or amperage in the search, and try just "19V 5.5 2.5", the relevance of those results is pretty spot on -- just double check the wattage/amperage in the description (there are lots of 90W supplies, those will work perfectly fine too) and make sure the description also mentions something like "Connector tip: 5.5/2.5mm" (might also be listed like "5.5x2.5" which is why I just suggest searching the raw numbers).