[time-nuts] USB problems and solutions - Some what Off Topic --> USB-C

Bob Camp kb8tq at n1k.org
Tue Jun 2 07:07:12 EDT 2015


Hi

The one thing I would be a bit careful about is the power levels. 

Consider an 8 port hub:

5V 3A from each would be 24A total. That’s pretty unusual. Most hubs
give you one or two high current outputs. 

20V 5A (100W ea) on 8 ports would be 800W. That’s not going to be cheap.

Yes, the 20V is an “optional” part of the whole thing. The 3A does not appear 
to be quite so easy to ignore. We’ll see what actually happens …..

Bob

> On May 30, 2015, at 11:28 AM, Neil Schroeder <gigneil at gmail.com> wrote:
> 
> USB-C will offer a number of things that I believe will be of benefit to
> time nuts everywhere:
> 
> 1) High current 5V up to 3A on every port
> 2) High voltage/current up to 20V/5A optionally on every port - sufficient
> to power some rubidium oscillators natively, and a small boost to get the
> rest of them.
> 3) a native UART channel - no more freaky USB interrupts/polling to get
> your pulses
> 4) single omnipurpose connector ends with no insertion dependencies
> 5) Better, simpler device enumeration - while I haven't seen how it
> addresses this personally, the stuff i have read is very promising.
> 
> Due to the switched controller nature of the interface, you should have
> less nonstandard crap that may cause your computer to hang or other issues
> related to drivers. The controller arbitrates a lot more setup details, and
> the number of those on the market will be limited compared to usb
> peripheral ICs.
> 
> This may be off topic from your off topic, but it seemed a good opportunity
> to share this  info.
> 
> NS9
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