Abstract: A fixation arrangement for detachably mounting a battery pack onto a cellular phone includes two parallel guide rails defined on the cellular phone, a sloping depression defined between the guide rails and sloping outward to the guide rails, a recess defined adjacent to the sloping depression and in a position opposite to the sloping direction of the depression, and a coupling plate integrally formed with the battery pack and having two parallel lips corresponding to the guide rails for slidably engaging onto the cellular phone, a U-shaped slot provided in a position corresponding to the recess and the slot and defining a tongue portion with a tip over the slot when the battery pack is engaged with the cellular phone, a tab protruding from the tip of the tongue portion for inserting into the slot when the battery pack is engaged with the cellular phone, and two cutouts respectively extending between one of the lips and the U-shaped slot and in a direction substantially parallel to the guide rails.

Abstract: An uninterruptable power supply module includes a DC power supply having an output for outputting a first DC voltage signal, a battery backup module in parallel connection to the output of the DC power supply and having an identical voltage level to that of the first DC voltage signal, boost converter means having an input coupled to the first DC voltage signal from the battery backup module for converting said first DC voltage signal to a second DC voltage signal, DC/AC conversion means having an input coupled to the second DC voltage signal from the boost converter means and an output for generating a first AC voltage signal in response to a variable duty cycle oscillation signal, pulse width modulator means powered by said battery backup module and having an output coupled to said DC/AC conversion means for generating said variable duty cycle oscillation signal, and shaping means having an input coupled to the first AC voltage signal from the DC/AC conversion means and an output for supplying a second AC v