5 Feb
2018
5 Feb
'18
noon
My EPROM Programmers all have a connection foir external power
specifically because sometimes USB can't provide the needed current.
bill
On 02/05/2018 02:06 PM, Chuck Guzis via cctalk wrote:
On 02/05/2018 10:20 AM, Mark G Thomas via cctalk
wrote:
2) Many of the chips were failing to program
because my Batronix
programmer apparently requires more current than my USB port provides.
This surprised me because I have been programming chips for years
using this programmer on this computer port successfully, and this
is the first I have had the problem. Using a Anker powered USB hub solved
things. My Batronix programmer even arrived with a cheap powered hub
when I ordered it, but I never used it because it was shipped with an
incompatible wall wart, but looking at it in the box gave me the idea
that this might be the issue.
You should be aware that many "thin"
Far East USB cables will not pass
the full USB 1.5A current without substantial voltage drop. I recently
ran into this with a new LG portable DVD drive. It refused to operate,
even though I'd just taken it out of the box. I replaced the "thin"
USB cable with several other "thin" ones that I had with the same
result. Finally, in desperation, I located a "thick" USB cable, plugged
the drive in, and discovered that it worked just fine.
Moral: There's a lot of garbage out there.
Rant: The whole scheme of supplying anything but low-current using USB
is a terrible idea. I have a similar gripe with barrel connectors,
which don't seem to enforce any standard at all regarding polarity or AC
vs. DC.
For my own projects I've taken to using mini XLR connectors. Perhaps not
optimal, but they're rugged enough.
--Chuck