Switching regulator having improved control circuiting

Claim 2

An electrical circuit comprising: energy storage inductor means; energy supply circuit means including on-off switching means for, when on, supplying energizing current from a D.C. voltage source to cause energy to be stored in said storage means; a load circuit inductively coupled to said storage means and including diode means and capacitive means connected in series and arranged in such a manner that inductive current flows to charge said capacitive means as energy is released from said storage means only when said switching means is off; and switch control means for controlling the ratio of switch on time to switch off time and comprising monitoring means including means connected in series with said storage means for sensing the magnitude of the energizing current during the switch on time and the magnitude of current relased from said storage means during the switch off time, and control circuit means connected to said monitoring means for controlling the ratio of switch on time to switch off time in dependence upon the increase in the magnitude of the sensed energizing current and the decrease in the magnitude of the sensed released current.

Claim 3

An electrical circuit as set forth in claim 1, including means directly responsive to the load voltage across said capacitive means for varying the ratio of the said switch on time to the said switch off time so a to vary the net change in energy being stored and released in accordance with the variations in the voltage across said capacitive means.

Claim 4

An electrical circuit as set forth in claim 1, including coupling means connected to said control circuit means for applying thereto a first signal which varies with changes in the amount of sensed energizing current and a second signal which varies with changes in the amount of sensed released current, said control circuit means including comparing means for providing a turn on signal or a turn off signal in dependence upon said first and second signals.

Claim 5

An electrical circuit as set forth in claim 3, including switch driver means for respectively controlling the on and off switch time durations in response to said turn on and turn off signals.

Claim 6

An electrical circuit as set forth in claim 1, wherein said switch contRol means includes comparator means having first and second inputs for providing a switch turn on signal when the potentials at said inputs have a first relationship and a switch turn off signal when said potentials have a second relationship, and coupling circuit means connecting said monitoring means with at least one of said inputs for varying said relationship as said supplied energizing current and said released inductive current change in magnitude.

Claim 7

An electrical circuit comprising: energy storage inductor means; energy supply circuit means including on-off switching means for, when on, supplying energizing current from a D.C. voltage source to cause energy to be stored in said storage means; a load circuit inductively coupled to said storage means and including diode means and capacitive means connected in series and arranged in such a manner that inductive current flows to charge said capacitive means as energy is released from said storage means only when said switching means is off; and switch control means for controlling the ratio of switch on time to switch off time and comprising monitoring means for sensing the magnitude of the energizing current during the switch on time and the magnitude of current released from said storage means during the switch off time, control circuit means connected to said monitoring means for controlling the ratio of switch on time to switch off time in dependence upon the increase in the magnitude of the sensed release current, said switch control means includes comparator means having first and second inputs for providing a switch turn on signal when the potentials at said inputs have a first relationship and a switch turn off signal when said potentials have a second relationship and coupling circuit means connecting said monitoring means with at least one of said inputs for varying said relationship as said supplied energizing current and said released inductive current change in magnitude, said connecting means includes capacitive means for applying to said at least one input a potential representative of the change in amplitude of a said current.

Claim 8

An electrical circuit comprising: energy storage inductor means; energy supply circuit means including on-off switching means for, when on, supplying energizing current from a D.C. voltage source to cause energy to be stored in said storage means; a load circuit inductively coupled to said storage means and including diode means and capacitive means connected in series and arranged in such a manner that inductive current flows to charge said capacitive means as energy is released from said storage means only when said switching means is off; and switch control means for controlling the ratio of switch on time to switch off time and comprising monitoring means for sensing the magnitude of the energizing current during the switch on time and the magnitude of current released from said storage means during the switch off time, control circuit means connected to said monitoring means for controlling the ratio of switch on time to switch off time in dependence upon the increase in the magnitude of the sensed release current, said switch control means includes comparator means having first and second inputs for providing a switch turn on signal when the potentials at said inputs have a first relationship and a switch turn off signal when said potentials have a second relationship and coupling circuit means connecting said monitoring means with at least one of said inputs for varying said relationship as said supplied energizing current and said released inductive current change in magnitude, said connecting means includes capacitive means for applying to said at least one input a potential representative of the change in amplitude of a said current.

Claim 9

An electrical circuit comprising: energy storage inductor means; energy supply circuit means including on-off switching means for, when on, supplying energizing current from a D.C. voltage source to cause energy to be stored in said storage means; a load circuit inductively coupled to said storage means and including diode means and capacitive means connected in series and arranged in such a manner that inductive current flows to charge said capacitive means as energy is released from said storage means only when said switching means is off; switch control means for controlling the ratio of switch on time to switch off time and comprising monitoring means for sensing the magnitude of the energizing current during the switch on time and the magnitude of current released from said storage means during the switch off time, control circuit means connected to said monitoring measn for controlling the ratio of switch on time to switch off time in dependence upon the increase in the magnitude of the sensed energizing current and the decrease in the magnitude of the sensed released current, said switch control means includes comparator means having first and second inputs for providing a switch turn on signal when the potentials at said inputs have a first relationship and a switch turn off signal when said potentials have a second relationship and coupling circuit means connecting said monitoring means with at least one of said inputs for varying said relationship as said supplied energizing current and said released inductive current change in magnitude, means for applying a potential to one of said comparator inputs in dependence upon the load voltage across said load circuit capacitive means to vary said potential relationship at said comparator inputs so as to vary the ratio of switch on time to switch off time in dependence upon said load voltagE.

Claim 10

An electrical circuit comprising: energy storage inductor means; energy supply circuit means including on-off switching means for, when on, supplying energizing current from a D.C. voltage source to cause energy to be stored in said storage means; a load circuit inductively coupled to said storage means and including diode means and capacitive means connected in series and arranged in such a manner that inductive current flows to charge said capacitive means as energy is released from said storage means only when said switching means is off; switch control means for controlling the ratio of switch on time to switch off time and comprising monitoring means for sensing the magnitude of the energizing current during the switch on time and the magnitude of current released from said storage means during the switch off time, control circuit means connected to said monitoring measn for controlling the ratio of switch on time to switch off time in dependence upon the increase in the magnitude of the sensed energizing current and the decrease in the magnitude of the sensed released current, said switch control means includes comparator means having first and second inputs for providing a switch turn on signal when the potentials at said inputs have a first relationship and a switch turn off signal when said potentials have a second relationship and coupling circuit means connecting said monitoring means with at least one of said inputs for varying said relationship as said supplied energizing current and said released inductive current change in magnitude, means for applying a potential to one of said comparator inputs in dependence upon the load voltage across said load circuit capacitive means to vary said potential relationship at said comparator inputs so as to vary the ratio of switch on time to switch off time in dependence upon said load voltagE.

Claim 11

An electrical circuit as set forth in claim 7, wherein said inductor means includes at least one winding connected in series with said switching means to receive said energizing current from said source when said switching means is on and said monitoring means includes an impedance connected in series with said winding so that a voltage is developed thereacross in proportion to the magnitude of the current flowing through said winding.

Claim 12

An electrical circuit as set forth in claim 8, wherein said inductor means includes a second winding connected across said load circuit so that current flows through said second winding only when said switch means is off, and said monitoring means includes a second impedance connected in series with said second winding across said load circuit so that a voltage is developed across said second impedance proportional to the magnitude of current flowing through said second winding.

Claim 13

An electrical circuit as set forth in claim 9, wherein said coupling means includes a first capacitive means for applying voltage changes across said first impedance to one of said comparator inputs and a second capacitive means for applying voltage changes across said second impedance to the second of said comparator inputs.

Claim 14

An electrical circuit as set forth in claim 10, wherein said first capacitive means is of greater capacitance than said second capacitive means to provide an initial potential unbalance at said comparator inputs as the voltage source is initially applied so that the regulated output voltage across said capacitive means gradually rises in magnitude.

Claim 15

An electrical circuit as set forth in claim 10, wherein said on-off switching means includes a transistor switching means having its emitter-collector path connected in series with said one winding to provide said energizing current thereto when said switching means is on, switch driver means responsive to each said turn on signal for providing base drive current for driving said transistor switching means on so that the magnitude of said energizing current increases with increases in said drive current, and means for limiting the magnitude of said energizing current.

Claim 16

An electrical circuit as set forth in claim 12, wherein said current limiting means includes circuit means for varying said drive current in response to the magnitude of said energizing current in such a manner that when said energizing current exceeds a predetermined level said drive current is decreased to decrease the magnitude of said energizing current.

Claim 17

An electrical circuit as set forth in claim 13, including current limiting transistor means responsive to a predetermined value of the voltage developed across said impedance in series with said one winding as energizing current flows therethrough to provide a low impedance path for a said turn on signal to thereby tend to prevent said driver means from responding to said signal and, hence, cause said drive current to decrease.

Claim 18

An electrical circuit comprising: energy storage inductor means; energy supplying circuit means including on-off switching means for, when on, supplying energizing current from a D.C. voltage source to cause energy to be stored in said storage means; a load circuit inductively coupled to said storage means and including diode means and capacitive means connected in series and arranged in such a manner that inductive current flows to charge said capacitive means as energy is released from said storage means only when said switching means is off; and switch control means for controlling the on and off conditions of said switching means and comprising means connected in series circuit with said storage means for providing a first manifestation which varies in dependence upon the amount of increase in the supplied energizing current when said switching means is on and a second manifestation which varies in dependence upon the amount of decrease in the released inductive current when said Switching means is off and control circuit means for controlling the on and off times of said switching means in respective dependence upon said first and second manifestations.

Claim 19

An electrical circuit comprising: energy storage inductor means; energy supplying circuit means including on-off switching means for, when on, supplying energizing current from a D.C. voltage source to cause energy to be stored in said storage means; a load circuit inductively coupled to said storage means and including diode means and capacitive means connected in series and arranged in such a manner that inductive current flows to charge said capacitive means as energy is released from said storage means only when said switching means is off; and switch control means for controlling the on and off conditions of said switching means and comprising means connected in series circuit with said storage means for providing a first manifestation which varies in dependence upon the amount of increase in the supplied energizing current when said switching means is on and a second manifestation which varies in dependence upon the amount of decrease in the released inductive current when said Switching means is off and control circuit means for controlling the on and off times of said switching means in respective dependence upon said first and second manifestations.

Claim 20

An electrical circuit as set forth in claim 15, including means directly responsive to the load voltage across said capacitive means for varying the ratio of the said switch on time to the said switch off time so as to vary the net change in energy being stored and released in accordance with the variations in the voltage across said capacitive means.

Claim 21

An electrical circuit comprising: energy storage inductor means; energy supplying circuit means including on-off switching means for, when on, supplying energizing current from a D.C. voltage source to cause energy to be stored in said storage means; a load circuit inductively coupled to said storage means and including diode means and capacitive means connected in series and arranged in such a manner that inductive current flows to charge said capacitive means as energy is released from said storage means only when said switching means is off; and switch control means for controlling the ratio of switch on time to switch off time and comprising monitoring means including means in series with said storage means for sensing the magnitude of the energizing current during the switch on time and the magnitude of the current released from said storage means during the switch off time, and control circuit means connected to said monitoring means for controlling said switching means so as to be normally on for a time duration sufficient that said energizing current increases by a given amount and is normally off for a time duration sufficient that a said given amount of energy is released.

Claim 22

An electrical circuit comprising: energy storage inductor means; energy supplying circuit means including on-off switching means for, when on, supplying energizing current from a D.C. voltage source to cause energy to be stored in said storage means; a load circuit inductively coupled to said storage means and including diode means and capacitive means connected in series and arranged in such a manner that inductive current flows to charge said capacitive means as energy is released from said storage means only when said switching means is off; and switch control means for controlling the ratio of switch on time to switch off time and comprising monitoring means including means in series with said storage means for sensing the magnitude of the energizing current during the switch on time and the magnitude of the current released from said storage means during the switch off time, and control circuit means connected to said monitoring means for controlling said switching means so as to be normally on for a time duration sufficient that said energizing current increases by a given amount and is normally off for a time duration sufficient that a said given amount of energy is released.

Claim 23

An electrical circuit comprising: an energy storage inductor-transformer having a primary winding and a secondary winding; switching means having on and off conditions for applying energizing current to said primary winding from a D.C. voltage source when said switching means is on; first flyback circuit means in parallel with said primary winding including a first diode and a first capacitor connected in series so that primary current flows therethrough due to energy released by said transformer to charge said first capacitor only when said switching means is off, second flyback circuit means connected in parallel with said secondary winding and including a second capacitor and a second diode connected in series therewith, and arranged so that secondary current flows therethrough to charge said second capacitor due to the energy released by said transformer when said switching means is off; switch control means for controlling the ratio of switch on time to switch off time and including: means for developing first and second voltages respectively proportional to the total energizing current when said switching means is on and to the total released current when said switching means is off; and, means for controlling said on and off conditions in dependence upon said first and second voltages.

Claim 24

An electrical circuit comprising: an energy storage inductor-transformer having a primary winding and a secondary winding; switching means having on and off conditions for applying energizing current to said primary winding from a D.C. voltage source when said switching means is on; first flyback circuit means in parallel with said primary winding including a first diode and a first capacitor connected in series so that primary current flows therethrough due to energy released by said transformer to charge said first capacitor only when said switching means is off, second flyback circuit means connected in parallel with said secondary winding and including a second capacitor and a second diode connected in series therewith, and arranged so that secondary current flows therethrough to charge said second capacitor due to the energy released by said transformer when said switching means is off; switch control means for controlling the ratio of switch on time to switch off time and including: means for developing first and second voltages respectively proportional to the total energizing current when said switching means is on and to the total released current when said switching means is off; and, means for controlling said on and off conditions in dependence upon said first and second voltages.

Claim 25

An electrical circuit comprising: energy storage inductor means; energy supplying circuit means including switching means for, when closed, supplying energizing current from D.C. voltage source to cause energy to be stored in said storage means; a load circuit inductively coupled to said storage means and including diode means and capacitive means connected in series and arranged in such a manner that inductive current flows to charge said capacitor as energy is released from said storage means only when said switching means is open; switch driver means for respectively closing and opening said switching means in response to turn on and turn off signals; comparing means having a first input and a second input and an output providing a said turn on signal when the potential at said second input is greater than that at said first input and a said turn off signal when the potenTial at said second input is less than that at said first input; means for applying a first potential proportional to the voltage level across said capacitor to said first input; means for applying a reference potential to said second input, with said reference potential being substantially equal to said first potential when the voltage level across said capacitor is at a desired level; and, means for varying the potential difference between said inputs as energy is being stored and released from said storage means in such a manner that while energy is being stored said potential difference varies in one direction to cause the potential at said second input to be less than that at said first input whereupon a said turn off signal is provided and while energy is being released said potential difference varies in an opposite direction to cause the potential at said second input to be greater than that at said first input whereupon a said turn on signal is provided.

Claim 26

An electrical circuit comprising: energy storage inductor means; energy supplying circuit means including switching means for, when closed, supplying energizing current from D.C. voltage source to cause energy to be stored in said storage means; a load circuit inductively coupled to said storage means and including diode means and capacitive means connected in series and arranged in such a manner that inductive current flows to charge said capacitor as energy is released from said storage means only when said switching means is open; switch driver means for respectively closing and opening said switching means in response to turn on and turn off signals; comparing means having a first input and a second input and an output providing a said turn on signal when the potential at said second input is greater than that at said first input and a said turn off signal when the potenTial at said second input is less than that at said first input; means for applying a first potential proportional to the voltage level across said capacitor to said first input; means for applying a reference potential to said second input, with said reference potential being substantially equal to said first potential when the voltage level across said capacitor is at a desired level; and, means for varying the potential difference between said inputs as energy is being stored and released from said storage means in such a manner that while energy is being stored said potential difference varies in one direction to cause the potential at said second input to be less than that at said first input whereupon a said turn off signal is provided and while energy is being released said potential difference varies in an opposite direction to cause the potential at said second input to be greater than that at said first input whereupon a said turn on signal is provided.

Claim 27

An electrical circuit as set forth in claim 19, wherein said varying means includes means for monitoring the energy being stored in said storage means and released therefrom and circuit means connected to at least one of said inputs for varying the potential difference therewith.

Claim 28

An electrical circuit as set forth in claim 20, wherein said monitoring means includes circuit means for developing a differential voltage which varies in one direction as energy is being stored and in the opposite direction as energy is released and said connecting circuit means includes means for changing the potentials at said input terminals in accordance with the changes in said differential voltage.

Claim 29

An electrical circuit as set forth in claim 21, including means for applying a relatively constant hysteresis voltage to one of said inputs so that said differential voltage must exceed said hysteresis voltage to obtain a said turn on signal or a said turn off signal.

Claim 30

An electrical circuit as set forth in claim 19, wherein said energy storage means includes at least one winding connected in series with said switching means to receive energizing current from said voltage source when said switch is closed and said potential difference varying means includes an impedance connected in series with said winding and said switching means across said source so as to develop a voltage thereacross in proportion to the magnitude of current flowing through said winding.

Claim 31

A switching regulator as set forth in claim 23, wherein said load circuit is connected in parallel with said series connected winding and impedance in such a manner that current flows through said diode means to charge said capacitive means only when said switch is open so that energy is released from said storage means.

Claim 32

A switching regulator as set forth in claim 24, wherein said potential varying means includes circuit means for applying to one of said inputs of said comparing means a potential representative of the direction and amount of change in the voltage developed across said impedance as energy is stored in and released from said energy storage means.

Claim 33

A switching regulator as set forth in claim 19, wherein said energy storage means includes an energy storage inductor-transformer having a primary winding and a secondary winding, said primary winding being connected in series with said switching means to receive energizing current from said voltage source when said switch is closed so as to increase the stored energy, a first impedance connected in series with said primary winding and said switching means across said voltage source, said load circuit being connected across said secondary winding with said diode means being arranged so that inductive current flows therethrough to charge said capacitive means from energy released by said storage means only when said switching means is open, said potential varying means including first and second impedance means respectively connected in series with said primary windinG and said secondary winding for developing first and second voltages thereacross as current flows through said respective windings, and circuit means for applying the changes in the differential voltage across said impedances to said first and second inputs of said comparing means.

Claim 34

A switching regulator as set forth in claim 26, including a second load circuit including a second capacitive means and a second diode means connected across said series connected primary winding and said first impedance with said diode means being arranged to conduct current therethrough to charge said second capacitive means from energy released from said storage means only when said switching means is open.

Claim 35

An electrical circuit comprising: energy storage inductor means; switching transistor means having its emitter-collector path connected in series with said inductor means to supply thereto output energizing current from a D.C. voltage source; means for providing switch turn on and turn off signals; switch driver means responsive to a said turn on signal for providing base drive current for driving said switching means on so that the magnitude of said output current increases with increases in said drive current; means for limiting the magnitude of said output current and including circuit means for varying said drive current in response to the magnitude of said output current in such a manner that when said output current exceeds a given level said drive current is decreased to decrease the magnitude of said output current, said circuit means includes impedance means connected in series with said inductor means for providing a control voltage which varies in magnitude proportional to said output current and current limiting transistor means responsive to a predetermined value of said control voltage for providing a low impedance path to said turn on signal to thereby tend to prevent said driver means from responding thereto to provide said drive current.

Claim 36

An electrical circuit comprising: energy storage inductor means; switching transistor means having its emitter-collector path connected in series with said inductor means to supply thereto output energizing current from a D.C. voltage source; means for providing switch turn on and turn off signals; switch driver means responsive to a said turn on signal for providing base drive current for driving said switching means on so that the magnitude of said output current increases with increases in said drive current; means for limiting the magnitude of said output current and including circuit means for varying said drive current in response to the magnitude of said output current in such a manner that when said output current exceeds a given level said drive current is decreased to decrease the magnitude of said output current, said circuit means includes impedance means connected in series with said inductor means for providing a control voltage which varies in magnitude proportional to said output current and current limiting transistor means responsive to a predetermined value of said control voltage for providing a low impedance path to said turn on signal to thereby tend to prevent said driver means from responding thereto to provide said drive current.

Claim 37

An electrical circuit as set forth in claim 28, including biasing means for applying a biasing potential to said current limiting transistor means such that said control voltage must decrease by an amount greater than said biasing potential before said low impedance path is removed so that said drive means will then respond to a said turn on signal to provide said base drive current for said switching transistor means.