On Wed, 24 Jan 2007 12:18:51 -0500, mm
wrote:

On Wed, 24 Jan 2007 10:30:10 -0600, Mark Lloyd
wrote:



If it's just speakerphone, that can be line powered.

I have a speakerphone at my desk that is line powered. I have another
one in the kitchen that uses a small wall adapter. It doesn't seem
worth it to plug in the adapter 24/7/365 for maybe 10 minutes a year I
would use the speakerphone. I guess I won't.


I have a speakerphone that connects directly to the phone line. It
doesn't have a dial but could be used to answer calls. That thing is
completely line powered.

Speed dial (and
caller ID) involve memory that has to be maintained all the time.

I know redial can work on line power. I can never remember how to
store things in memory.


My father bought a s mall one-piece phone in about 1980. It had redial
(for some strange reason, that worked only when set to pulse dialing)
and 3 programmable buttons (supposed to be used as a substitute for
the nonexistent 911 service). It had a small backup battery. Maybe
just so it would retain memory while disconnected from the phoneline.

Batteries may be needed to provide power when the phone is "on hook",
since little current can be drawn from the line at that time.

The corded phone that needed batteries had a bunch of features,
including a display of the time and date, and the number just dialed.
While it needed 4 AA to do this I don't know.


Was the display lighted? That takes a lot of power.

I have an early, 1971, GE FM radio with pushbutton numbers and digital
tuning that can run down 2 nine volt back up alkaline batteries in
about 5 hours. Yet I have a watch that can keep time for 5 years on a
much smaller battery. Strange.

And new cordless phones can't be turned off. They say better design
enables them to stay charged for what, 3 or 4 days, even when on.
Yeah, but if one could turn them off, so they didn't ring when the
phone rang, but I could place a call from one, they would last 20 or
30 days. That would be really good. Maybe I will have to take mine
apart and modify it.

My current cordless phone has no on-off switch, but the ringer can be
disabled. However, it still lights up when it would otherwise be
ringing.
--
Mark Lloyd
http://notstupid.laughingsquid.com

"Unlike biological evolution. 'intelligent design' is
not a genuine scientific theory and, therefore, has
no place in the curriculum of our nation's public
school classes." -- Ted Kennedy