US4377776A — Duty-cycle controlled inverter power supply for a…

Claim 1

Independent Claim 246 words

A television receiver, inverter power supply with duty-cycle control, comprising: a deflection winding; a deflection generator for developing scanning current in said deflection winding; a source of direct voltage; a power transformer including a primary winding and a supply winding; controllable switching means having a main current path coupled to said source and to said primary winding so that on-off switching of the conduction in said main current path develops an alternating polarity voltage across said primary winding, thereby developing a supply voltage across said supply winding; control means coupled to said switching means for producing said on-off switching at a nominal duty cycle of a predetermined percentage, including a synchronizing transformer with a first winding that has said deflection current flowing therein to magnetically saturate the core of said synchronizing transformer during the entirety of each deflection cycle except during intervals within each deflection cycle that encompass the zero-crossover instants of the deflection current to develop across a second winding of said synchronizing transformer switching signals for said controllable switching means so as to synchronize the zero-crossover instants of said power transformer alternating polarity voltage to corresponding zero-crossover instants of said deflection current; means for developing a control signal that differs with different duty-cycle percentages of said on-off switching; and means coupled to said control means and responsive to said control signal for adjusting the duty cycle of said on-off switching so as to oppose changes in said duty cycle away from the nominal percentage.

Claim 2

Dependent Claim 246 words

A television receiver, inverter power supply with duty-cycle control, comprising: a deflection winding; a deflection generator for developing scanning current in said deflection winding; a source of direct voltage; a power transformer including a primary winding and a supply winding; controllable switching means having a main current path coupled to said source and to said primary winding so that on-off switching of the conduction in said main current path develops an alternating polarity voltage across said primary winding, thereby developing a supply voltage across said supply winding; control means coupled to said switching means for producing said on-off switching at a nominal duty cycle of a predetermined percentage, including a synchronizing transformer with a first winding that has said deflection current flowing therein to magnetically saturate the core of said synchronizing transformer during the entirety of each deflection cycle except during intervals within each deflection cycle that encompass the zero-crossover instants of the deflection current to develop across a second winding of said synchronizing transformer switching signals for said controllable switching means so as to synchronize the zero-crossover instants of said power transformer alternating polarity voltage to corresponding zero-crossover instants of said deflection current; means for developing a control signal that differs with different duty-cycle percentages of said on-off switching; and means coupled to said control means and responsive to said control signal for adjusting the duty cycle of said on-off switching so as to oppose changes in said duty cycle away from the nominal percentage.

Claim 3

Dependent Claim 246 words

A television receiver, inverter power supply with duty-cycle control, comprising: a deflection winding; a deflection generator for developing scanning current in said deflection winding; a source of direct voltage; a power transformer including a primary winding and a supply winding; controllable switching means having a main current path coupled to said source and to said primary winding so that said on-off switching of the conduction in said main current path develops an alternating polarity voltage across said primary winding, thereby developing a supply voltage across said supply winding; control means coupled to said switching means for producing said on-off switching of the conduction in said main path, including a synchronizing transformer with a first winding that has said deflection current flowing therein to magnetically saturate the core of said synchronizing transformer during the entirety of each deflection cycle except during intervals within each deflection cycle that encompass the zero-crossover instants of the deflection current to develop across a second winding of said synchronizing transformer switching signals for said controllable switching means so as to synchronize the zero-crossover instants of said power transformer alternating polarity voltage to corresponding zero-crossover instants of said deflection current; means for developing a signal representative of the current in said main path; and means coupled to said control means and responsive to said main path current representative signal for adjusting the duty cycle of said on-off switching so as to oppose changes in the amplitude of the current in said main path.

Claim 4

Dependent Claim 246 words

A television receiver, inverter power supply with duty-cycle control, comprising: a deflection winding; a deflection generator for developing scanning current in said deflection winding; a source of direct voltage; a power transformer including a primary winding and a supply winding; controllable switching means having a main current path coupled to said source and to said primary winding so that said on-off switching of the conduction in said main current path develops an alternating polarity voltage across said primary winding, thereby developing a supply voltage across said supply winding; control means coupled to said switching means for producing said on-off switching of the conduction in said main path, including a synchronizing transformer with a first winding that has said deflection current flowing therein to magnetically saturate the core of said synchronizing transformer during the entirety of each deflection cycle except during intervals within each deflection cycle that encompass the zero-crossover instants of the deflection current to develop across a second winding of said synchronizing transformer switching signals for said controllable switching means so as to synchronize the zero-crossover instants of said power transformer alternating polarity voltage to corresponding zero-crossover instants of said deflection current; means for developing a signal representative of the current in said main path; and means coupled to said control means and responsive to said main path current representative signal for adjusting the duty cycle of said on-off switching so as to oppose changes in the amplitude of the current in said main path.

Claim 5

Dependent Claim 40 words

A power supply according to claims 1 or 2 wherein the alternating polarity voltage developed across said primary winding is a substantially rectangular wave voltage having a magnitude during both polarity intervals that is substantially that of said direct voltage.

Claim 6

Dependent Claim 37 words

A power supply according to claims 1 or 2 wherein the alternating polarity voltage developed across said primary winding is a substantially rectangular wave voltage, the duty cycle of said rectangular wave voltage nominally being fifty percent.

Claim 7

Dependent Claim 30 words

A power supply according to claim 4 wherein said adjusting means opposes changes in the duty cycle of said rectangular wave voltage away from the nominal fifty percent duty cycle.

Claim 8

Dependent Claim 53 words

A power supply according to claim 5 wherein said switching means comprises first and second switching elements, each having a main current path, the main current paths of the two elements, the source of direct voltage and the transformer primary winding being coupled to one another so as to form a push-pull arrangement.

Claim 9

Dependent Claim 22 words

A power supply according to claim 6 wherein said power transformer comprises a self-regulating saturating core transformer for regulating said supply voltage.

Claim 10

Dependent Claim 28 words

A power supply according to claim 6 wherein said power transformer comprises a high leakage transformer with said supply winding being magnetically loosely coupled to said primary winding.

Claim 11

Dependent Claim 35 words

A power supply according to claim 8 including a ferroresonant saturable reactor circuit coupled to said power transformer supply winding for regulating said supply voltage by the ferroresonant operation of said ferroresonant saturable reactor circuit.

Claim 12

Dependent Claim 58 words

A power supply according to claim 6 wherein at least one of said switching elements has a control terminal that controls the on-off switching of the conduction in the main current path of said one element and wherein the switching on or the switching off of said one element produces the opposite type switching of the other element.

Claim 13

Dependent Claim 53 words

A power supply according to claim 10 wherein said power transformer includes a feedback winding coupled to the control terminal of said one element for switching on the conduction in the main current path of said one element when the conduction in the main current path of the other element is switched off.

Claim 14

Dependent Claim 24 words

A power supply according to claims 1 or 2 wherein said power transformer comprises a self-regulating saturating core transformer for regulating said supply voltage.

Claim 15

Dependent Claim 30 words

A power supply according to claims 1 or 2 wherein said power transformer comprises a high leakage transformer with said supply winding being magnetically loosely coupled to said primary winding.

Claim 16

Dependent Claim 35 words

A power supply according to claim 13 including a ferroresonant saturable reactor circuit coupled to said power transformer supply winding for regulating said supply voltage by the ferroresonant operation of said ferroresonant saturable reactor circuit.

Claim 17

Dependent Claim 226 words

A deflection synchronized switching power supply for a television display system, comprising: a deflection winding; a deflection generator coupled to said deflection winding for generating scanning current in said deflection winding during a deflection interval; a power transformer having primary and supply windings; a source of direct voltage coupled to said primary winding; signal means coupled to said deflection generator for developing first and second control signals indicative of the occurrence of the zero-crossover instants of said scanning current within the trace and retrace intervals, respectively, of said deflection interval; controllable switching means having first and second main current paths coupled to said power transformer; control means coupled to said switching means and responsive to said first and second control signals for alternately switching said first and second main current paths into conduction near a respective one of said zero-crossover instants so as to develop an alternating polarity rectangular-wave voltage across said transformer primary winding for generating a supply voltage across said supply winding; means for developing a control signal representative of the current in at least one of said first and second main current paths; and means coupled to said control means and responsive to said control signal for adjusting the duty cycle of said rectangular wave voltage so as to oppose changes in the magnitude of the current in said one main current path.

Claim 18

Dependent Claim 226 words

A deflection synchronized switching power supply for a television display system, comprising: a deflection winding; a deflection generator coupled to said deflection winding for generating scanning current in said deflection winding during a deflection interval; a power transformer having primary and supply windings; a source of direct voltage coupled to said primary winding; signal means coupled to said deflection generator for developing first and second control signals indicative of the occurrence of the zero-crossover instants of said scanning current within the trace and retrace intervals, respectively, of said deflection interval; controllable switching means having first and second main current paths coupled to said power transformer; control means coupled to said switching means and responsive to said first and second control signals for alternately switching said first and second main current paths into conduction near a respective one of said zero-crossover instants so as to develop an alternating polarity rectangular-wave voltage across said transformer primary winding for generating a supply voltage across said supply winding; means for developing a control signal representative of the current in at least one of said first and second main current paths; and means coupled to said control means and responsive to said control signal for adjusting the duty cycle of said rectangular wave voltage so as to oppose changes in the magnitude of the current in said one main current path.

Claim 19

Dependent Claim 52 words

A power supply according to claim 15 wherein said control means alternately switches said first and second main current paths so as to develop said rectangular wave voltage having a nominal fifty percent duty cycle and wherein said adjusting means opposes changes in said duty cycle away from the nominal fifty percent.

Claim 20

Dependent Claim 29 words

A power supply according to claim 16 wherein said first and second main current paths are coupled to the primary winding of said power transformer in a push-pull arrangement.

Claim 21

Dependent Claim 44 words

A power supply according to claim 16 wherein said signal means comprises a transformer having a first winding with said scanning current flowing therein and having at least one other winding for developing at least one of said first and second control signals thereacross.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1986-03-21	1986-09-20	1987-03-22	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1990-03-21	1990-09-20	1991-03-22	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1994-03-21	1994-09-20	1995-03-22	$7700.00	Window Closed / Lapsed

Duty-cycle controlled inverter power supply for a television receiver

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