David VanHorn wrote:
> At 09:19 AM 9/16/2003 -0500, michael brown wrote:
>
>> Does anyone have any idea how much power you could tap
>> from the line without causing it to go off hook?
>
> very little.

Well, I'm not trying to heat my house or anything, just snag a little
bit of juice to run some low power equipment for a moment.

> current drawn during ring is how the co tells that you're off hook.
>
> have a look at the link above, it will answer many questions.

Thanks for the link, I liked the article as it was quite informative.
Obviously a certain amount of power is allowed to be drawn during
ringing as you can ring up to five hefty electro-mechanical bells.  Now
they're called REN's and 1 REN is the equivalent of an old style phone,
modern phones are usually well under 1 REN.  Since they don't exactly
say how much a REN is, I'm trying to deduce it from the requirements.

The phone is required to maintain approximately (depends upon testing
method) 1500 ohms of AC impedance during ringing.  Since the ringer
voltage is roughly 100V, wouldn't it be fair to say that I'm entitled to
about 67mA of current during a ring per phone?

At any rate, I should be able to charge a large cap by drawing a few mA
between calls with circuitry sleeping until a ring occurs.  After that
everything would wake up and run until brown out occurs as the cap is
drained.  It appears this would likely violate part 68 requirements for
a telephone device, but I think it should work in theory.  What say ye?
;-)

michael

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