US 5,969,438 A · Electronic apparatus having a power supply unit that can switch between internal and external power sources

Abstract

Disclosed is an electric power supplying unit for use in an electronic apparatus and includes an external AC adapter externally connected to the body of the electronic apparatus for receiving an external AC power source. An internal AC adapter is accommodated into the body of the electronic apparatus for receiving an external AC power source. An AC power source input detection circuit is provided within the internal AC adapter for detecting whether the external AC power source is input to the internal AC adapter. The power supply unit further includes power source switching circuit responsive to the detection output of the AC power source input detection circuit for switching the power supply to the electronic apparatus from the output of the external AC adapter to the output of the internal AC adapter.

Claims8

Dependent claims

An electric power supplying unit for use in an electronic apparatus comprising:

an external AC adapter externally connected to the body of said electronic apparatus for receiving an external AC power source;
an internal AC adapter accommodated into the body of said electronic apparatus for receiving an external AC power source;
an AC power source input detection means provided within said internal AC adapter for detecting whether the external AC power source is input to said internal AC adapter;
power source switching means responsive to the detection output of said AC power source input detection means for switching the power supply to said electronic apparatus from the output of said external AC adapter to the output of said internal AC adapter;
and
wherein said output of said internal AC adapter is directly connected to said electronic apparatus.

3 more elements

A portable electronic apparatus comprising:

an external AC adapter externally connected to the body of said electronic apparatus for receiving an external AC power source;
an internal AC adapter accommodated into the body of said electronic apparatus for receiving the external AC power source;
a DC/DC converter for level converting the DC output of said external AC adapter or said internal AC adapter;
a system load driven by the DC output of said DC/DC converter;
an AC power source input detection means provided within said internal AC adapter for detecting whether the external AC power source is input to said internal AC adapter;
power source switching means responsive to the detection output of said AC power source input detection means for switching the power source to said DC/DC converter from the output of said external AC adapter to the output of said internal AC adapter;
and
wherein said output of said internal AC adapter is directly connected to said DC/DC converter.

5 more elements

Dependencies are inferred from the claim text.

Electronic apparatus having a power supply unit that can switch between internal and external power sources

Life of this patent

Electronic apparatus having a power supply unit that can switch between internal and external power sources

Life of this patent

Abstract

Claims8