12VAC adapter reads aprox. 24VAC

Thread Starter

iONic

Joined Nov 16, 2007
1,654
Just had an AC adapter send to my father place to replace a bad one that runs his Christmas tree lights. the old one was spec'd at:
INPUT: 120VAC
OUTPUT: 12VAC, 1000mA

The new one, seen in the link below, is spec'd the same, but reading about 24V on his analog multi-meter.

Is this normal for one without being under load??
Should I try it or send it back?

https://www.amazon.com/gp/product/B00417WE2K/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
 

Thread Starter

iONic

Joined Nov 16, 2007
1,654
Thanks guys. The lights work (fiber-optics), but the changing colors are not working. Shouldn't be a connection to the supply. I think there is a color wheel at the base of the tree which is probably not rotating, not sure why. Will have my dad keep an eye on it.
 

AlbertHall

Joined Jun 4, 2014
11,314
No doubt a ordinary transformer, they usually rate them for the voltage at the rated load, high off load is normal.
Max.
No, it can't be just a transformer as it is specified to run from 100V or 240V input so it really must be switch mode (it is DC output). In that case I would expect the output voltage to be close.
Does the label on it say it is 12V?
 

AlbertHall

Joined Jun 4, 2014
11,314
I just spotted this line in the description:
"Output : 12V 1A Max (Compatible 0.3A-1A Power)"
This is probably saying that there is a minimum load of 0.3A so that might account for the discrepancy.
 
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