Stuart B Koch

US Patent:

52066185, Apr 27, 1993

Filed:

Nov 26, 1991

Appl. No.:

7/798922

Inventors:

Stuart Koch - Philadelphia PA

Assignee:

SPD Technologies Inc. - Philadelphia PA

International Classification:

H01F 708

US Classification:

335253

Abstract:

A magnetic latch includes a coil, a frame receiving magnetic flux from the coil when energized, a latching member mounted in the frame and rotatably movable between first and second positions with the latching member providing a magnetic flux bridge between flux carrying means of the frame by contacting the flux carrying means with the latching member is in a first position, a magnet providing magnetic flux carried by the flux carrying means and a portion of the latching member for magnetically retaining the latching member is a first position with the coil is deenergized and a spring biasing the latching member towards a second position with force sufficient to overcome magnetic retention of the latching member at the first position when the coil is providing magnetic flux to the flux carrying members of the frame in the direction opposite of that of flux provided by the magnet.

US Patent:

52354881, Aug 10, 1993

Filed:

Feb 5, 1992

Appl. No.:

7/831427

Inventors:

Stuart Koch - Philadelphia PA

Assignee:

Brett Products, Inc. - Philadelphia PA

International Classification:

H05K 141

US Classification:

361 45

Abstract:

Disclosed is a helically wound core of ferrous material used as a differential current sensor core in the ground fault sensor of a ground fault interrupter circuit. The ferrous material comprises a single strand of wire which is wound in helical fashion to create a tubular shaped core comprising a series of wire loops (all part of the single strand) parallel to each other and running the length of the tubular shape. The core is placed around a pair of current carrying lines to be monitored for ground faults (one line leading to and one line leading away from the power source) to interact with the magnetic fields of the lines. Toroidally wound leads wrapped around the wire core act as a secondary and are connected to a ground fault interruption circuit to shut off the power to the conducting lines in the event that the sensor detects a difference in current in the lines. By utilizing wire as the core material, the amount of surface area can be greatly increased over the prior art cores without increasing the cross-sectional area (and, therefore, the overall size) of the core.