Random notes from mg

a blog by Marius Gedminas

Marius is a Python hacker. He works for Programmers of Vilnius, a small Python/Zope 3 startup. He has a personal home page at http://gedmin.as. His email is marius@gedmin.as. He does not like spam, but is not afraid of it.

Sun, 10 Dec 2006

Nokia 770 + USB power injector

A coworker made me a USB power injector for my Nokia 770 (I'm useless with a soldering iron). Here it is in all its glory, next to the tiny USB keyboard I plan to use it with:

Nokia 770, tiny USB keyboard, USB power injector

Five days later I discover that it doesn't work any more. Actually, it works, but the battery is dead. I left the battery connected to the voltage regulator, and that was enough to drain it.

Wikipedia says that carbon-zinc 9V batteries have a typical capacity of 400 mAh. ThoughtFix measured the circuit power readings at 4.62 mA with both USB ports disconnected. That's enough to drain a 400 mAh battery in 86 hours or 3.6 days. And here I thought it would last for months...

Time to buy a new battery. And this time I'll keep it disconnected when I'm not using it.

posted at 16:52 | tags: | permanent link to this entry | 1 comments
Were did you get the tiny keyboard from? Is it USB powered?

Are you willing to sell it?

please email me :-)
posted by Benjamin Spenger at Mon Nov 3 14:24:40 2014

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