US 4,948,987 A · Secondary electric power source produced by current flow through a primary a.c. power circuit

Abstract

Voltage drop developed across a transformer primary winding coupled in series with a primary a.c. power circuit including an a.c. power source and an a.c. load is utilized to provide a secondary source of a.c. power having secondary voltage level stability which is substantially independent from otherwise influential changes in primary power circuit levels. Secondary power stabilization is mainly established by constant voltage limiting of the primary winding excitation by the forward voltage drop developed across an arrangement of semiconductor junctions coupled in parallel with the primary winding. The transformer may be used to change the source level of the secondary a.c. power which is produced, and to obtain electrical isolation between the primary power circuit and any ancillary circuits coupled with the secondary a.c. power source.

Claims20

Dependent claims

Power supply method for obtaining a secondary source of electrical power from current flowing through an alternating current primary power circuit, comprising the steps of:

providing a primary power circuit including a source of a.c. power and a load;
coupling a primary winding means of a transformer effectively in series with primary power circuit;
exciting the primary winding means by current flow through the primary power circuit;
developing a voltage drop across the primary winding means by said current flow therethrough;
coupling bilateral semiconductor device means effectively in parallel with the primary winding means;
predetermining a bilateral level of forward voltage drop permitted across said semiconductor device means;
limiting the voltage drop developed across the primary winding means to that of the the bilateral level of semiconductor device forward voltage drop;
providing the transformer with a main secondary winding means which may serve to excite a secondary load means.

5 more elements

Power supply means producing a secondary source of power which is derived from current flowing through a portion of a primary power circuit including seriate coupling of a source of a.c. electric power and a primary a.c. load means, comprising:

transformer means comprising inductively coupled primary and secondary winding means;
means for coupling said primary winding means substantially in series with the primary power circuit and develop an a.c. voltage drop across the primary winding means as a result of a.c. current flow through the primary power circuit;
semiconductor means coupled substantially in parallel with te primary winding means and effective for limiting the value of the developed a.c. voltage drop to a small and substantially constant value;
and,
secondary load means coupled with said secondary winding means.

2 more elements

Power supply means producing a secondary source of power which is derived from current flowing through a portion of a primary power circuit, comprising:

means for producing a primary source of alternating current electric power having a value of at least several volts;
primary load means coupled in series with and drawing alternating current from the primary source;
transformer means comprising inductively coupled primary and secondary winding means;
means for seriately coupling the transformer's said primary winding means with the primary source of electric power and the primary load means;
and,
means for limiting any peak-to-peak a.c. voltage drop which may develop across the primary winding means as a result of primary load means current flow to an essentially constant level;
and,
secondary load means coupled with said secondary winding means.

5 more elements

Dependencies are inferred from the claim text.

Secondary electric power source produced by current flow through a primary a.c. power circuit

Life of this patent

Secondary electric power source produced by current flow through a primary a.c. power circuit

Life of this patent

Abstract

Claims20