USB to power up your CID on analogue phone, without using AA batteries
I have this analogue that comes with CID (caller identification number) display, the problem with this phone is that it requires 3 X AA batteries to run it. So one simple way to do away the battery is to power the display with USB. There are plenty of USB ports nearby which is not used such as those behind my pc monitor.
USB power is a very good option because the current phone requires 4.5 DC to drive it, hence the 5V DC from USB is perfectly nice in voltage range.
[TO BE UPDATED…]