charliem_1216 wrote:
> --- In "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
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