High voltage power supply for copying apparatus or the like

Claim 2

A high-voltage, direct-current power supply designed to operate on a non-regulated source of alternating current potential; said power supply comprising: a rectangular stack of laminations forming a transformer core having a central opening; a stack of laminations creating a magnetic flux path across the opening in said stack to form a figure-eight shaped transformer core having first and second central openings; a single primary winding encircling one leg only of said rectangular stack so as to pass through said first central opening; a single secondary winding encircling the same one leg of the rectangular stack so as to pass through said second central opening, said secondary winding having first and second secondary terminals; said primary winding having first and second primary terminals connecting to the non-regulated source of alternating current potential, and said primary winding having sufficient turns so as to saturate the flux path of said secondary winding when the source of alternating current potential is supplying the lowest potential which is to be expected; a first capacitor connected across said secondary terminals to produce resonance in said secondary winding at approximately the frequency of the non-regulated source; a rectifier circuit including rectifying diodes and capacitors having a pair of alternating current input terminals connected to said secondary terminals and having a pair of direct current output terminals; said capacitor and the elements of said rectifier circuit lying adjacent to legs of said rectangular stack which legs are not encircled by said primary and secondary windings so as to lie primarily within the bounds of the smallest rectangular solid which can contain the transformer core and the windings; and a protective substance surrounding all of the above elements so as to encapsulate the entire power supply.

Claim 3

A power supply in accordance with claim 1 wherein the rectifier circuit includes two rectifiers which are positioned on opposite sides of a leg of the rectangular stack which leg is not encircled by said primary and secondary windings, and wherein the rectifier circuit also includes two capacitors which are each positioned between said secondary winding and one of said rectifiers and which are both oriented parallel to the flattest sides of the transformer stacks.

Claim 4

A power supply in accordance with claim 1 wherein the first capacitor is positioned in said central opening between said secondary winding and a leg of the rectangular stack.

Claim 5

A power supply in accordance with claim 1 to which is added a bleeder resistor connected across the direct current output terminals and positioned to lie essentially within said smallest rectangular solid.

Claim 6

A power supply in accordance with claim 1 to which is added a pair of resistors connecting said direct current output terminals to ground and positioned to lie essentially within said rectangular solid, whereby positive and negative output voltages with respect to ground may be obtained.

Claim 7

A power supply in accordance with claim 5 to which is added a rectifier and filter stage comprising a diode and a capacitor connected between one of said direct current output terminals and ground, whereby a reduction in the power supply ripple is achieved.

Claim 8

A power supply in accordance With claim 1 to which is added a second capacitor having one terminal connecting to one of said secondary terminals, said one secondary terminal being the secondary terminal which is not at the same A.C. potential as said direct current output terminals, and said second capacitor having a second terminal which is a third direct current output terminal.

Claim 9

A power supply in accordance with claim 7 which includes a diode interconnecting said third direct current output terminal with a given one of the other two direct current output terminals.

Claim 10

A power supply in accordance with claim 8 which includes a rectifier and a third capacitor connected serially between said third direct current output terminal and the given one of the other two direct current output terminals with the rectifier adjacent said third direct current output terminal and oriented so that the third direct current output terminal connects to the cathode of one rectifier and to the anode of another rectifier.

Claim 11

A high-voltage, direct-current power supply for operation on a non-regulated source of alternating current potential; said power supply comprising: a rectangular stack of laminations forming a transformer core having a central opening; a stack of laminations creating a magnetic flux path across the opening in said rectangular stack of laminations to form a figure-eight shaped transformer core having first and second central openings; a single primary winding encircling one leg of said rectangular stack so as to pass through said first central opening; a single secondary winding encircling one leg of said rectangular stack so as to pass through said second central opening, said secondary winding having first and second secondary terminals, and said secondary winding having sufficient turns tO develop between said secondary terminals a peak-to-peak potential whose magnitude is between one-half and two-thirds of the desired peak direct current output potential of the supply when the flux path of the secondary winding is driven to saturation; said primary winding having first and second primary terminals connecting to the non-regulated source of alternating current potential, and said primary winding having sufficient turns so as to saturate the flux path of said secondary winding when the source of alternating current potential is supplying the lowest potential which is to be expected; a voltage doubling rectifier circuit having a pair of alternating current input terminals connected to said secondary terminals and having a pair of direct current output terminals, said rectifier circuit producing a D.C. potential at said output terminals whose peak magnitude roughly equals the peak-to-peak magnitude generated by said secondary winding; and a first capacitor connected across said secondary terminals to resonate with said secondary winding at approximately the frequency of the non-regulated source of alternating current potential.

Claim 12

A high-voltage, direct-current power supply for operation on a non-regulated source of alternating current potential; said power supply comprising: a rectangular stack of laminations forming a transformer core having a central opening; a stack of laminations creating a magnetic flux path across the opening in said rectangular stack of laminations to form a figure-eight shaped transformer core having first and second central openings; a single primary winding encircling one leg of said rectangular stack so as to pass through said first central opening; a single secondary winding encircling one leg of said rectangular stack so as to pass through said second central opening, said secondary winding having first and second secondary terminals, and said secondary winding having sufficient turns tO develop between said secondary terminals a peak-to-peak potential whose magnitude is between one-half and two-thirds of the desired peak direct current output potential of the supply when the flux path of the secondary winding is driven to saturation; said primary winding having first and second primary terminals connecting to the non-regulated source of alternating current potential, and said primary winding having sufficient turns so as to saturate the flux path of said secondary winding when the source of alternating current potential is supplying the lowest potential which is to be expected; a voltage doubling rectifier circuit having a pair of alternating current input terminals connected to said secondary terminals and having a pair of direct current output terminals, said rectifier circuit producing a D.C. potential at said output terminals whose peak magnitude roughly equals the peak-to-peak magnitude generated by said secondary winding; and a first capacitor connected across said secondary terminals to resonate with said secondary winding at approximately the frequency of the non-regulated source of alternating current potential.

Claim 13

A power supply in accordance with claim 10 to which is added a second capacitor connecting one of said secondary terminals to a third output terminal, said one secondary terminal being the secondary terminal which is not at the same alternating current potential as said pair of output terminals.

Claim 14

A power supply in accordance with claim 11 to which is added a rectifier connecting said third output terminal to one of said pair of direct current output terminals.

Claim 15

A power supply in accordance with claim 10 to which is added resistors connecting each of said pair of direct current output terminals to ground.

Claim 16

A power supply in accordance with claim 10 wherein the voltage doubling rectifier circuit includes a pair of rectifiers and a pair of capacitors all of which, together with said first capacitor, are positioned close to legs of the rectangular stack of laminations which legs are not encircled by the transformer windings; and all of which are mainly confined to within the smallest rectangular solid which can encompass the transformer core and windings.

Claim 17

A power supply in accordance with claim 14 wherein at least one of the power supply capacitors is positioned within the second central opening in the figure-eight shaped transformer core.

Claim 18

A high-voltage direct-current power supply comprising a power transformer having primary and secondary windings, means connecting said primary winding to an unregulated source of alternating current potential, a first capacitor connected across said secondary winding to produce resonance in said secondary winding at approximately the frequency of the unregulated source, second and third capacitors connected in series, means connecting one end of said secondary winding to the junction of said second and third capacitors, means including a first rectifier connecting the other end of said secondary winding to said second capacitor, means including a second rectifier connecting said other end of said secondary winding to said third capacitor, thereby to develop across said second and third series connected capacitors a first full wave rectifier output voltage of one polarity, and means including a fourth capacitor connected to said other end of said secondary winding for deriving a second output voltage of the opposite polarity from said first output voltage.

Claim 19

A high-voltage direct-current power supply comprising a power transformer having primary and secondary windings, means connecting said primary winding to an unregulated source of alternating current potential, a first capacitor connected across said secondary winding to produce resonance in said secondary winding at approximately the frequency of the unregulated source, second and third capacitors connected in series, means connecting one end of said secondary winding to the junction of said second and third capacitors, means including a first rectifier connecting the other end of said secondary winding to said second capacitor, means including a second rectifier connecting said other end of said secondary winding to said third capacitor, thereby to develop across said second and third series connected capacitors a first full wave rectifier output voltage of one polarity, and means including a fourth capacitor connected to said other end of said secondary winding for deriving a second output voltage of the opposite polarity from said first output voltage.

Claim 20

The power supply arrangement set forth in claim 16, wherein said second output voltage is an alternating current voltage of a frequency equal to that of said unregulated source.

Claim 21

The power supply arrangement of claim 16, which includes a third rectifier connected from said fourth capacitor to ground, thereby to increase the peak amplitude of said opposite polarity second output voltage.