Switched telephone network connection unit for PDA has modem powered from network through transformer isolated chopper inverter power supply

摘要

A switched telephone network connection unit has a modem (2) connected to a network socket (P) with isolated (12) power supply through a chopper (11) and transformer (15) with inverter (17) connected to the secondary (16) and auxiliary start up power supply selected by a switch (18). Includes Independent claims for cable reel and rotating electrical generator to charge a capacitor auxiliary supply and for modem state switching using an energy detector (7) in the computer data connector (5, 6)