Transformer apparatus for use in insulated switching power supply apparatus with reduction of switching noise

• US 6,377,153 B1
• Filed: 08/30/2000
• Issued: 04/23/2002
• Est. Priority Date: 08/31/1999
• Status: Expired due to Fees

• Current Assignee: Agilent Technologies Europe BV (Agilent Technologies, Inc.)
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Wakamatsu, Hideki, Yamanaka, Haruhiko
• Primary Examiner(s): MAI, ANH T
• Application Number:
  US09/652,372
• Time in Patent Office: 601 Days
• Field of Search: 336/223, 336/84.R, 336/84.C, 336/182, 336/183, 336/225, 336/229, 336/90
• US Class Current: 336/84.00R
• CPC Class Codes: H01F 19/08 Transformers having magnetic bias, e.g. for handling pulses
• CPC Class Codes: H01F 27/36 Electric or magnetic shields or screens movable for varying inductance H01F21/10
• CPC Class Codes: H01F 27/363 made of electrically conductive material
• CPC Class Codes: H01F 3/10 Composite arrangements of magnetic circuits
• CPC Class Codes: H01F 30/16 Toroidal transformers

Abstract

A transformer apparatus which can reduce a switching noise current flowing between a primary side ground and a secondary side ground is provided. The transformer apparatus includes a first core having a first primary winding wound around the first core, and second core having the substantially same structure as that of the first core, and having a second primary winding wound around the second core. The second primary winding is connected in parallel to the first primary winding. The transformer apparatus further includes a third core having a secondary winding around the third core, which is entirely and electrostatically shielded by a first conductor housing. The third core is arranged so as to be sandwiched between the first and second cores via first and second electrostatically shielding disks electrically connected to a second conductor housing. The first, second and third cores are electrically connected by the second conductor housing operating as one-turn winding, and are electrostatically and magnetically shielded from the outside of the transformer apparatus by the second conductor housing.

Claims

1. A transformer apparatus comprising:

a first core having a first primary winding wound around said first core;

a second core having a substantially same structure as that of said first core, and having a second primary winding wound around said second core, said second primary winding being connected in parallel to said first primary winding;

a first conductor housing;

a second conductor housing; and

a third core having a secondary winding around said third core, said third core being entirely and electrostatically shielded by said first conductor housing,

wherein said third core is arranged so as to be sandwiched between said first and second cores respectively via first and second electrostatically shielding disks electrically connected to said second conductor housing, and

wherein said first, second and third cores are electrically connected by said second conductor housing operating as one-turn winding, and are electrostatically and magnetically shielded from the outside of said transformer apparatus by said second conductor housing.

2. A transformer apparatus comprising:

first and second transformers having a substantially same structure as each other,

wherein said first transformer comprises;

a first core having a first primary winding wound around said first core;

a first conductor housing;

a second conductor housing; and

a third core having a first secondary winding wound around said third core, said third core being entirely and electrostatically shielded by said first conductor housing,

wherein said first and third cores are arranged via a first electrostatically shielding disk electrically connected to said second conductor housing, are electrically connected by said second conductor housing operating as one-turn winding, and are electrostatically and magnetically shielded from the outside of said transformer apparatus by said second conductor housing,

wherein said second transformer comprises;

a second core having a second primary winding wound around said second core, said second primary winding being connected in parallel to said first primary winding;

a third conductor housing;

a fourth conductor housing; and

a fourth core having a second secondary winding wound around said fourth core, said fourth secondary winding being connected in series to said first secondary winding, said fourth core being entirely and electrostatically shielded by said third conductor housing, and

wherein said second and fourth cores are arranged via a second electrostatically shielding disk electrically connected to a fourth conductor housing, are electrically connected by said fourth conductor housing operating as one-turn winding, and are electrostatically and magnetically shielded from the outside of said transformer apparatus by said fourth conductor housing.

3. The transformer apparatus as claimed in claim 2,

wherein said first and second transformers are apposed with each other.