On 08/14/2015 6:30 PM, micky wrote:
Online I see for sale a wireless keyboard/mouse, and it says about it

"Auto Sleep And Wake Feature

This keyboard also features an auto sleep and auto wake mode. If there
is a long period of inactivity, the keyboard will automatically go into
a sleep mode. To exit sleep mode, press any key."

Why does it have any need to go to sleep. Why would it use any power
if no one is pressing a key? This is not a cordless phone that waits
for phone calls, whose battery drains even when not in use.

(For that matter. why don't cordless phones have on/off switches. They
can go without charging for about 2 days. If you could rely on the
ringer in the other room and turn the cordless phone OFF, they wouldnt'
need a charge for 10 days or more. )

This is the item. Before you buy it, there's a newer version now.
http://www.amazon.com/FAVI-FE01-BL-W...wifi+keyboards

Thanks.


A wireless keyboard uses Bluetooth to communicate with the computer.
This takes energy and drains the battery eventually.

What the keyboard does is it goes into a low power mode where the
Bluetooth transceiver is shut down, and the keyboard likely only scans
for presses once a second or so. So now you are down to the microamp
power load and batteries can provide that for along time, compared to
milliamps of draw when busy with Bluetooth and keystrokes.

Cordless phones do have low power mode, but they still have to 'listen'
for the RF signal to wake them up, and a receiver does draw more power
than simply sleeping.

Cell phones low power mode still transmits and receives RF so the
various features are kept up to date - location, chat with local cell
towers to keep the device able to receive, etc.

John :-#)#

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