US 2008/0290732 A1 · POWER SWITCH SYSTEM

Abstract

A power switch system (200) for selectively providing power from a primary power source and a secondary power source to an electronic device, includes a detecting module (24), and a selecting module (30). The detecting module is connected to the primary power source. The selecting module is connected to an output terminal of the detecting module, the primary power source, and the secondary power source, and outputs the power from the primary power source to the electronic device if the primary power source is available. The detecting module is configured for determining whether the primary power source is available for the electronic device and generating a switch signal if the primary power source is unavailable, and the selecting module outputs power from the secondary power source to the electronic device in response to the switch signal.

Claims9

Dependent claims

A power switch system for selectively providing power from a primary power source and a secondary power source to an electronic device, the power switch system comprising:

a detecting module connected to the primary power source,
a selecting module connected to an output terminal of the detecting module, the primary power source, and the secondary power source, and outputting power from the primary power source to the electronic device if the primary power source is available;
the detecting module being configured for determining whether the primary power source is available for the electronic device and generating a switch signal if the primary power source is unavailable, and the selecting module outputting power from the secondary power source to the electronic device in response to the switch signal.

A power switch system for selectively providing power from a primary power source and a secondary power source to an electronic device, comprising:

a detecting module connected to the primary power source configured for determining whether the primary power source is available for the electronic device and generating a detected signal;
and
a selecting module configured for selectively outputting the power from one of the primary power source and the secondary power source to the electronic device according to the detected signal, the selecting module comprising a first transistor, a second transistor, a third transistor, and an output terminal for outputting the power;
wherein
the emitter of the first transistor is grounded;
the base of the first transistor is connected to an output terminal of the detecting module for receiving the detected signal;
the base of the second transistor is connected to the collector of the first transistor;
the emitter of the second transistor is connected to the primary power source for receiving power therefrom;
the collector of the second transistor is connected to the output terminal;
the base of the third transistor is connected to the output terminal of the detecting module for receiving the detected signal, the emitter of the third transistor is connected to the secondary power source for receiving power therefrom;
the collector of the third transistor is connected to the output terminal.

8 more elements

Dependencies are inferred from the claim text.

Power switch system

Life of this patent

Power switch system

Life of this patent

Abstract

Claims9