Re: Plug in power voltage?

["Matt Blaze" matthew.blaze]

On Aug 21, 2009, at 7:07, Klas Strandberg wrote:

> Hi folks!
>
> It would help me and users if I better knew about the plug in power
> voltage that different recorders provide.
>
> This is the test:
>
> 1/ Connect a potentiometer and a mA meter in series between input
> and ground.
> 2/ Set the potentiometer so that the mA meter shows 0,5 mA.
> 3/ Measure the voltage between input and ground.
>
> For the moment I am specially interested in the voltage that Sony
> PCM-D50 provides at a given current, like 0,5 mA.
>
> Klas.
>
>
>

[Corrected -- it's the Sony D50, not the D10, of course. -matt]

OK, I just did the LS-10, too:   1.93V

To summarize (view in a monospace font):

MODEL           V (unloaded)    V @ 0.50 mA    Load (Ohms)
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D
Sony D50          2.82            0.52           1030
Zoom H4n          2.84            1.82           3606
Olympus LS10      3.02            1.93           3828


So the Sony is an outlier here.

Note that my 0.50 mA current adjustment was only approximate -- I set
the load resistor to get as close to 0.500 mA to flow as I could, but
really got only within +/- 1 % or so.  So the loaded voltage isn't
exactly R * .0005, because the current wasn't exactly 0.5000 mA.  It's
just close.  Ohm's law still applies in Philadelphia, in spite of what
the numbers above might suggest!

V measurements were done with a recently calibrated Fluke 189.
Current was measured with a Fluke 289, also recently calibrated.

-matt


mab blogs at http://www.crypto.com/blog/