AC to DC Wall Adapter:Vout 12Vdc Measured 19.5V?

[david90]

On the adapter, Vout is 12Vdc but when I measured it with a voltmeter it shows 19.5V. Is there a typo or does the voltage somehow drops down to 12V when in use with a load?

 

[dduardo]

Are you sure you not measuring RMS value?

Vrms = Vo/sqrt(2)

 

[david90]

Are you sure you not measuring RMS value?

Vrms = Vo/sqrt(2)

RMS?? The output is DC.

 

[dlgoff]

The output probably has a lot of ripple. Your measuring meter is probably is seeing it.
If your meter can measure AC try it an see how much.

 

[Paulanddiw]

I've seen this a lot of times. I think there must be a lot of "droop" in the converter's output. At rated load it's probably at stated voltage, but open circuit, it's high. I think if you should use these converters at their rated load. Load too high -- burn them out; load too low -- maybe damage your load.

 

[mezarashi]

I agree. Most voltage values given are rated values at full load (i.e. rated current).