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US 8,797,771 B1Granted
Capacitor based AC to DC step up converter
AssigneeAlfred E. Mann Foundation for Scientific Research
InventorEdward K. F. Lee
Life of this patent
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Abstract
An AC-DC step-up converter circuit architecture for generating multiple output voltages, both positive and negative, in an implantable biomedical device is disclosed. Switches and active rectifiers are used inside the converter for charging capacitors from the AC source and delivering currents to the loads. Regulated output voltages with high power efficiency are obtained by controlling the on/off times of the switches using feedback loops that include integrator circuits configured to provide control parameters related to the various output voltages and their associated predetermined reference voltages.
Claims23
A timing controlled capacitor based AC-DC step-up converter configured to supply regulated output voltages to a load circuit comprising:
- a time varying input signal source providing a time varying input signal having positive and negative peaks;
- a first input capacitor having first and second terminals, the first terminal being coupled to the input signal source, the second terminal being coupled to a converter first positive output through a first rectifier, the second terminal further being switchably coupled to a converter ground through a first switch and to a converter second positive output through a second switch;
- a first switch controller coupled to said first switch for controlling the time at which the first switch is closed and the duration of such switch closure, wherein said first switch controller comprises a first integrator configured to integrate the difference between a function of the converter first positive output and a predetermined first reference voltage to provide thereby a first control signal and wherein the first switch controller causes the first switch to close when the voltage at the first input capacitor second terminal falls below ground level and further causes the first switch to open when the voltage at the first input capacitor second terminal falls below the value of the first control signal;
- and
- a second switch controller coupled to said second switch for controlling the time at which the second switch is closed and the duration of such switch closure, wherein said second switch controller comprises a second integrator configured to integrate the difference between a function of the converter second positive output and a predetermined second reference voltage to provide thereby a second control signal and wherein the second switch controller causes the second switch to close when the voltage at the first input capacitor second terminal rises above the converter second positive output and further causes the second switch to open when a function of the voltage at the first input capacitor second terminal rises above the value of the second control signal.
2 more elements
A timing controlled capacitor based AC-DC step-up converter configured to supply regulated output voltages to a load circuit comprising:
- a time varying input signal source providing a time varying input signal having positive and negative peaks;
- a second input capacitor having first and second terminals, the first terminal being coupled to the input signal source, the second terminal being coupled to a converter first negative output through a second rectifier, the second terminal further being switchably coupled to the converter ground through a third switch and to a converter second negative output through a fourth switch;
- a third switch controller coupled to said third switch for controlling the time at which the third switch is closed and the duration of such switch closure, wherein said third switch controller comprises a third integrator configured to integrate the difference between a function of the converter first negative output and a predetermined third reference voltage to provide thereby a third control signal and wherein the third switch controller causes the third switch to close when the voltage at the second input capacitor second terminal rises above ground level and further causes the third switch to open when the voltage at the second input capacitor second terminal rises above the value of the third control signal;
- and
- a fourth switch controller coupled to said fourth switch for controlling the time at which the fourth switch is closed and the duration of such switch closure, wherein said fourth switch controller comprises a fourth integrator configured to integrate the difference between a function of the converter second negative output and a predetermined fourth reference voltage to provide thereby a fourth control signal and wherein the fourth switch controller causes the fourth switch to close when the voltage at the second input capacitor second terminal is lower than the converter fourth negative output and further causes the fourth switch to open when a function of the voltage at the second input capacitor second terminal falls below the value of the fourth control signal.
2 more elements
A method of supplying regulated output voltages to a load circuit utilizing a timing controlled capacitor based AC-DC step-up converter configured to supply regulated output voltages to a load circuit, the converter comprising:
- a time varying input signal source providing a time varying input signal having positive and negative peaks;
- and
- a first input capacitor having first and second terminals, the first terminal being coupled to the input signal source, the second terminal being coupled to a converter first positive output through a first rectifier, the second terminal further being switchably coupled to a first fixed dc voltage source through a first switch;
- the method comprising the steps of:
- (a) comparing the voltage at the first input capacitor second terminal to the first fixed dc voltage;
- (b) closing the first switch for a first predetermined time interval when the voltage at the first input capacitor second terminal is less than the first fixed dc voltage;
- (c) conducting current through the first rectifier from the time varying input signal source to the load circuit when the first input capacitor second terminal voltage is greater than the converter first positive output voltage;
- (d) providing an average value of the first positive output and multiplying the average value of the first positive output by a gain factor to provide a scaled first positive output and comparing the scaled first positive output to a predetermined first reference voltage;
- (e) decreasing the first predetermined time interval when the scaled first positive output exceeds the predetermined first reference voltage, and increasing the first predetermined time interval when the scaled first positive output is less than the predetermined first reference voltage;
- and
- (f) repeating steps (a) through (e).
8 more elements
A method of supplying regulated output voltages to a load circuit utilizing a timing controlled capacitor based AC-DC step-up converter configured to supply regulated output voltages to a load circuit, the converter comprising:
- a time varying input signal source providing a time varying input signal having positive and negative peaks;
- and
- a second input capacitor having first and second terminals, the first terminal being coupled to the input signal source, the second terminal being coupled to a converter first negative output through a second rectifier, the second terminal further being switchably coupled to a second fixed dc voltage source through a third switch,
- the method comprising the steps of:
- (l) comparing the voltage at the second input capacitor second terminal to the second fixed dc voltage;
- (m) closing the third switch for a third predetermined time interval when the voltage at the second input capacitor second terminal is greater than the second fixed dc voltage;
- (n) conducting current through the second rectifier from the time varying input signal source to the load circuit when the second input capacitor second terminal voltage is less than the converter first negative output voltage;
- (o) providing an average value of the first negative output and multiplying the average value of the first negative output by a gain factor to provide a scaled first negative output and comparing the scaled first negative output to a predetermined third reference voltage;
- (p) decreasing the third predetermined time interval when the scaled first negative output is less than the predetermined third reference voltage and increasing the third predetermined time interval when the scaled first negative output is greater than the predetermined third reference voltage;
- and
- (q) repeating steps (l) through (p).
8 more elements
A timing controlled capacitor based AC-DC step up converter configured to supply regulated output voltages to a load circuit comprising:
- a time varying input signal source providing a time varying input signal having positive and negative peaks;
- a first input capacitor having first and second terminals, the first terminal being coupled to the input signal source, the second terminal being coupled to a converter first output through a first rectifier, the second terminal further being switchably coupled to a first fixed dc voltage source through a first switch;
- and
- a first switch controller coupled to said first switch for controlling the time at which the first switch is closed and the duration of such switch closure, wherein said first switch controller comprises a first integrator configured to integrate the difference between a function of the converter first output and a predetermined first reference voltage to provide thereby a first control signal and wherein the first switch controller causes the first switch to close when the voltage at the first input capacitor second terminal falls below ground level and further causes the first switch to open when the voltage at the first input capacitor second terminal falls below the value of the first control signal.
1 more element
A timing controlled capacitor based AC-DC step up converter configured to supply regulated output voltages to a load circuit comprising:
- a time varying input signal source providing a time varying input signal having positive and negative peaks;
- comprising:
- a second input capacitor having first and second terminals, the first terminal being coupled to the input signal source, the second terminal being coupled to a converter third output through a second rectifier, the second terminal further being switchably coupled to a second fixed dc voltage source through a third switch;
- and
- a third switch controller coupled to said third switch for controlling a time at which the third switch is closed and a duration of such switch closure, wherein said third switch controller comprises a third integrator configured to integrate the difference between a function of the converter third output and a predetermined third reference voltage to provide thereby a third control signal and wherein the third switch controller causes the third switch to close when the voltage at the second input capacitor second terminal rises above ground level and further causes the third switch to open when the voltage at the second input capacitor second terminal rises above the value of the third control signal.
2 more elements
A timing controlled capacitor based AC-DC step-up converter configured to supply regulated output voltages to a load circuit comprising:
- a time varying input signal source providing a time varying input signal having positive and negative peaks;
- a first input capacitor having first and second terminals, the first terminal being coupled to the input signal source, the second terminal being coupled to a converter first positive output through a first rectifier, the second terminal further being switchably coupled to a converter ground through a first switch and to a converter second positive output through a second switch;
- a first switch controller coupled to said first switch for controlling the time at which the first switch is closed and the duration of such switch closure, wherein said first switch controller comprises a first integrator configured to integrate the difference between a function of the converter first positive output and a predetermined first reference voltage to provide thereby a first control signal and wherein the first switch controller causes the first switch to close when the voltage at the first input capacitor second terminal falls below ground level and further causes the first switch to open when the voltage at the first input capacitor second terminal falls below the value of the first control signal;
- a second switch controller coupled to said second switch for controlling the time at which the second switch is closed and the duration of such switch closure, wherein said second switch controller comprises a second integrator configured to integrate the difference between a function of the converter second positive output and a predetermined second reference voltage to provide thereby a second control signal and wherein the second switch controller causes the second switch to close when the voltage at the first input capacitor second terminal rises above the converter second positive output and further causes the second switch to open when a function of the voltage at the first input capacitor second terminal rises above the value of the second control signal;
- a second input capacitor having first and second terminals, the first terminal being coupled to the input signal source, the second terminal being coupled to a converter first negative output through a second rectifier, the second terminal further being switchably coupled to the converter ground through a third switch and to a converter second negative output through a fourth switch;
- a third switch controller coupled to said third switch for controlling the time at which the third switch is closed and the duration of such switch closure, wherein said third switch controller comprises a third integrator configured to integrate the difference between a function of the converter first negative output and a predetermined third reference voltage to provide thereby a third control signal and wherein the third switch controller causes the third switch to close when the voltage at the second input capacitor second terminal rises above ground level and further causes the third switch to open when the voltage at the second input capacitor second terminal rises above the value of the third control signal;
- and
- a fourth switch controller coupled to said fourth switch for controlling the time at which the fourth switch is closed and the duration of such switch closure, wherein said fourth switch controller comprises a fourth integrator configured to integrate the difference between a function of the converter second negative output and a predetermined fourth reference voltage to provide thereby a fourth control signal and wherein the fourth switch controller causes the fourth switch to close when the voltage at the second input capacitor second terminal is lower than the fourth negative converter output and further causes the fourth switch to open when a function of the voltage at the second input capacitor second terminal falls below the value of the fourth control signal.
5 more elements
Dependencies are inferred from the claim text.