Measuring AC voltage

TheRAV

I bought a ds203, hardware version 2.81, ds203 Mini DSO SYS Ver 1.64 DS203 Mini DSO APP (Plus A1) Ver 1.13

Constant voltage is measured correctly. Measured 12.23volt.
AC voltage measuring incorrectly overstates approximately 2.9 times.

See screenshots

sagittarius

Test AC signal to select AC gear

TheRAV

Is anybody here?

TheRAV

I did it.


The voltage is the same. Delta V +29.2V

AC DC No difference.

http://www.hobbyprojects.com/osc ... tical_controls.html
Hardware or software error?
You can test on another device?

sagittarius

TheRAV 发表于 2015-11-2 18:52
I did it.

Are you sure you 10.9 volt AC signal?You can take other test machine, compare the results.See if the signal itself.

TheRAV

Yes. I'm sure.
I measured two multimeters, that I trust.

TheRAV

Yes. I'm sure.
I measured two multimeters, that I trust.

sagittarius

TheRAV 发表于 2015-11-9 16:04
Yes. I'm sure.
I measured two multimeters, that I trust.

Ac signal measured with a multimeter test not fully, sometimes you can use other oscilloscope tests, the comparison results.

TheRAV

This is an ordinary 9V power supply.
Need another oscilloscope?
What are you talking about?
))))
Good.
I can make measurements on the another oscilloscope  tomorrow and take a photo.

btidey

The 29.2 DeltaV is a peak to peak measurement of the AC signal. A multimeter will normally give the RMS of the AC signal (which gives the equivalent average 'power' of the AC signal. For a sinusoidal waveform peak to peak AC is 2 * Root(2) of the rms value (2.82). So for a multimeter rms reading of 10.9V then I would expect a peak to peak signal of 30.82V which is not far from what you see.