Hey Jason-
Thanks for the reply. I have inquired with the manufacturer regarding the
USB compliance. We are likely to now supply 5V to the spectrometer externally.
I agree with you that we might overheat it in that way, so we will put this 5V
under digital control of the TS-7260. We will only turn on the spectrometer
after the USB comes fully functional. In that way, I hope we can prevent the
overheating you describe.
Thanks for the help.
Bill
--- In Jason Stahls <> wrote:
>
> charliem_1216 wrote:
> > --- In "wrsimpson.alaska" <wrsimpson.alaska@>
> > wrote:
> >
> >> Hey Charliem_1216-
> >>
> >> Thanks for the information. I'm using the 2.4 kernel, so I don't know
> >> the overcurrent condition in the syslog.
> >>
> >> Regarding one or two ports, I see that the USB power on the TS-7260
> >> schematic is just wired to both of the 5V power pins on the connector, so
> >> I don't think I get any more power by using two connectors.
> >>
> >
> > OK, I thought the MIC2026 chip was doing the current limiting for two
> > channels.
> >
> > AFAIK, there are low power devices (never draw more than 100 mA) and high
> > power devices (up to 500 mA). High power devices are not supposed to
> > exceed 100 mA draw until the host configures the device, after the host has
> > determined that it has 500 mA available. You should check with Ocean
> > Optics to see whether the microcontroller in the spectrometer obeys that
> > restriction.
>
> Also, many chipsets don't obey that restriction as I believe the standby
> current on a USB port (before enumeration) is only in the mA range...
> Also, if the schematic shows both ports connected to the same 5v supply
> then I really doubt the board is fully complying with the power specs
> for USB. Odds are if you connected the spectrometer direct to +5v with
> no bus connection it would probably overheat as it does now....
>
> --
> Jason Stahls
>
------------------------------------
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/ts-7000/
<*> Your email settings:
Individual Email | Traditional
<*> To change settings online go to:
http://groups.yahoo.com/group/ts-7000/join
(Yahoo! ID required)
<*> To change settings via email:
<*> To unsubscribe from this group, send an email to:
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
|