Portable computer having built-in AC adapter incorporating a space efficient electromagnetic interference filter

A volume efficient power supply, said power supply converting alternating current to direct current, comprising:

• a first connector for electrically connecting said power supply to an alternating current main;
• a bridge rectifier circuit having an AC input side electrically connected to said first connector and not to any capacitor, and
• a DC output side, said bridge rectifier circuit converting alternating current to direct current;
• an electromagnetic interference filter having an input side electrically connected to said DC output side of said bridge rectifier circuit and an output side, said electromagnetic interference filter removing noise from said direct current output by said bridge rectifier circuit;
• and
• a second connector for electrically connecting said output side of said electromagnetic interference filter and an output line.

A volume efficient power supply converting alternating current to direct current, comprising:

• a first connector for electrically connecting said power supply to an alternating current main;
• a bridge rectifier circuit having an AC input side electrically connected to said first connector and a DC output side, said bridge rectifier circuit converting alternating current to direct current;
• an electromagnetic interference filter having an input side electrically connected to said DC output side of said bridge rectifier circuit and an output side, said electromagnetic interference filter removing noise from said direct current output by said bridge rectifier circuit;
• and
• a second connector for electrically connecting said DC output side of said electromagnetic interference filter and an output line;
• wherein said electromagnetic interference filter further comprises a multilayer ceramic capacitor electrically connected in parallel with said DC output side of said bridge rectifier circuit;
• wherein said electromagnetic interference filter further comprises:
• first inductor means for providing a common mode choke of line noise, said first inductor means electrically connected in parallel with said multilayer ceramic capacitor;
• and
• second inductor means for providing a differential mode choke of line noise, said second inductor means electrically connected to said first inductor means;
• and further comprising a bulk capacitor electrically connected to said first and second inductor means, said bulk capacitor converting direct current output by said bridge rectifier circuit into stored energy for transfer to energy demanding components coupled to said output line;
• wherein said volume efficient power supply is coupled to a portable personal computer, and housed within a main chassis portion of said portable personal computer.

A volume efficient AC adapter for a portable personal computer, said AC adapter converting alternating current to direct current, comprising:

• a first connector for electrically connecting said AC adapter to an alternating current main;
• a bridge rectifier circuit having an AC input side electrically connected to said first connector and not to any capacitor, and
• a DC output side,
• said bridge rectifier circuit converting alternating current to direct current;
• an electromagnetic interference filter having an input side electrically connected to said DC output side of said bridge rectifier circuit and an output side, said electromagnetic interference filter removing noise from said direct current output by said bridge rectifier circuit;
• and
• a second connector for electrically connecting said output side of said electromagnetic interference filter and said portable personal computer.

An AC adapter for a portable personal computer, said AC adapter converting alternating current to direct current, comprising:

• a first connector for electrically connecting said AC adapter to an alternating current main;
• a bridge rectifier circuit having an AC input side electrically connected to said first connector and not to any capacitor, and
• a DC output side,
• said bridge rectifier converting alternating current to direct current;
• an electromagnetic interference filter having an input side electrically connected to said DC output side of said bridge rectifier circuit and an output side, said electromagnetic interference filter including:
• a multilayer ceramic capacitor electrically connected in parallel with said DC output side of said bridge rectifier circuit;
• first inductor means for providing a common mode choke of line noise, said first inductor means electrically connected in parallel with said multilayer ceramic capacitor;
• second inductor means for providing a differential mode choke of line noise, said second inductor means electrically connected to said first inductor means;
• a bulk capacitor electrically connected in parallel with said output side of said electromagnetic interference filter, said bulk capacitor converting direct current output by said bridge rectifier circuit into stored energy for transfer to said portable personal computer;
• a second connector for electrically connecting said output side of said electromagnetic interference filter and said portable personal computer.

For a portable personal computer having a main chassis portion and at least one energy demanding component positioned within said main chassis portion, an internal AC adapter positioned within said main chassis portion, said internal AC adapter converting alternating current received from an alternating current main to direct current for transmission to said at least one energy demanding component, said internal AC adapter comprising:

• a first connector for electrically connecting said internal AC adapter to said alternating current main;
• a bridge rectifier circuit having an AC input side electrically connected to said first connector and not to any capacitor, and
• a DC output side;
• and
• a space efficient electromagnetic interference filter having an input side electrically connected to said DC output side of said bridge rectifier circuit and an output side;
• said bridge rectifier circuit converting alternating current received from said first connector to direct current for transmission to said space efficient electromagnetic interference filter;
• said space efficient electromagnetic interference filter including at least one capacitative element for filtering noise from said direct current transmitted to said space efficient electromagnetic filter by said bridge rectifier circuit;
• said at least one energy-demanding component being electrically connected to said output side of said space efficient electromagnetic interference filter and receiving filtered direct current therefrom;
• whereby placement of said electromagnetic interference filter on said DC output side of said bridge rectifier circuit enables usage of reduced size capacitors for said at least one capacitative element.