Comment on 🔌 testing an a/c adapter before use-- 12v PSU measures at 18+v, increasing. Is that a problem?
cmnybo@discuss.tchncs.de 3 days ago
Is that adapter heavy? It sounds like an unregulated transformer type power supply. It’s not unusual for those to output twice their rated voltage with no load. They will damage equipment that requires a regulated supply.
diyrebel@lemmy.dbzer0.com 2 days ago
It’s a lightweight switching power supply.
But I also wonder why you say it sounds like the linear transformer variety. My understanding is the linear transformers give a more clean and stable output. I think transformers are more robust and longer lasting. OTOH, it’s not good that they warm up and waste energy (“vampire bricks”), hog space… and not good that they are hard-wired to only handle 110v or 220v, not either/or.
Overall I prefer the small light switching PSUs, despite the fact they are often badly built and have short lifetimes.
cmnybo@discuss.tchncs.de 2 days ago
A switching power supply should be regulated. The one you have is defective. Some do have a minimum load, but I’ve never seen that on an adapter that can be unplugged from the load.
A linear power supply has a linear regulator and will supply its rated voltage with very little ripple. The unregulated power supplies are just a transformer, rectifier & capacitor. They only provide their rated voltage when they are supplying their full rated current and there will be a lot of ripple.