US 7,889,041 B2 · Systems and methods for forming an isolated transformer

Abstract

A transformer to isolate a primary winding from a signal winding include a primary substrate (which may comprise a printed circuit board (PCB)) and a secondary substrate. The primary and secondary substrates may each have three openings to allow first and second E-E core halves to be joined therebetween. A first insulator may be disposed between the primary and secondary substrates to isolate the primary substrate from the secondary substrate. A second insulator may secure the primary and secondary substrates in place and insulate the secondary substrate from the core. The primary and secondary substrates may each include a Faraday shield its outer layers. A shield slit to prevent shorting between the legs of the E-E core may be formed by cutting a channel in the shield between the opening of the primary and secondary substrates. A retaining clip may be used to clamp together the primary substrate, first and second core E-E core halves, secondary substrate and second insulator. A primary winding and sense winding may be disposed within the primary substrate and a signal winding may be disposed within the secondary substrate. The primary, sense, and signal windings may be positioned so that the magnetic flux produced by the primary winding passes through the signal and sense windings in substantially equal proportions. The primary and signal winding may enter the E-E core from opposite directions to choke any common mode current therebetween.

Claims18

Dependent claims

An isolated transformer, comprising:

a primary substrate comprising a primary winding and a sense winding, wherein the primary winding comprises one or more traces on the primary substrate, and wherein the sense winding comprises one or more traces on the primary substrate;
a secondary substrate disposed proximate to the primary substrate comprising a signal winding, wherein the signal winding comprises one or more traces on the secondary substrate;
a first insulator disposed between the primary substrate and the secondary substrate, wherein the first insulator is configured to isolate the primary substrate from the secondary substrate;
and
a core disposed in proximity to the primary substrate and the secondary substrate to electromagnetically couple the primary winding to the sense winding and the signal winding.

2 more elements

An isolated printed circuit board (PCB) transformer, comprising:

a substantially symmetric E-E core comprising a first leg, a second center leg, and a third leg;
a primary PCB comprising an inner layer and an outer layer, the primary PCB comprising a first opening, a second center opening, and a third opening, wherein the first, second center, and third primary PCB openings are configured to receive the first, second center, and third legs of the E-E core, the primary PCB comprising:
a primary winding formed as a plurality of PCB traces on the inner layer of the primary PCB,
a sense winding formed as a plurality of PCB traces on the inner layer of the primary PCB, and
a primary Faraday shield disposed on the outer layer of the primary PCB;
a secondary PCB comprising an inner layer and an outer layer, the secondary PCB comprising a first opening, a second center opening, and a third opening, wherein the first, second center, and third secondary PCB openings are configured to receive the first, second center, and third legs of the E-E core, the secondary PCB comprising:
a signal winding formed as a plurality of PCB traces on the inner layer of the secondary PCB, and
a secondary Faraday shield disposed on the outer layer of the secondary PCB;
a first insulator disposed between the primary PCB and secondary PCB, wherein the first insulator is configured to isolate the primary PCB from the secondary PCB, the first insulator comprising three hollow flanges configured to receive the E-E core legs, and wherein the first, second center, and third openings of the secondary PCB are configured to receive the hollow flanges;
and
a second insulator to isolate the secondary PCB from the core comprising three flanges configured to be received by the first, second center, and third openings of the secondary PCB and to be maintained within the three hollow flanges of the first insulator,
wherein, the primary Faraday shield and the secondary Faraday shield are substantially symmetric relative to the E-E core, and wherein the sense winding and the signal winding are positioned relative to the primary winding such that a magnetic flux produced by the primary winding passes through the sense winding and the signal winding in substantially equal proportion.

9 more elements

Dependencies are inferred from the claim text.

Systems and methods for forming an isolated transformer

Life of this patent

Systems and methods for forming an isolated transformer

Life of this patent

Abstract

Claims18