# US 2021/0243865 A1 · Tubular led ballast buck-boost converter

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- Number: US 2021/0243865 A1
- Document ID: US20210243865A1
- Status: Published application
- Kind: A1
- Application number: 17/167,399
- Filed: 2021-02-04
- Published: 2021-08-05
- Earliest claimed: 2020-02-05
- Assignees: Energy Focus, Inc.
- Applicants: Energy Focus, Inc.
- Inventors: Laszlo A. Takacs; Attila Tomasovics; Matthew Downie; John McGreevey
- Web page: https://patentgrep.com/patent/US20210243865A1

## CPC

- H05B 45/3725: Switched mode power supply [SMPS]
- H05B 45/375: using buck topology
- H05B 45/38: using boost topology
- F21K 9/278: Arrangement or mounting of circuit elements integrated in the light source
- F21Y 2103/00: Elongate light sources, e.g. fluorescent tubes
- F21Y 2115/10: Light-emitting diodes [LED]
- H02M 3/1582: {Buck-boost converters (H02M3/1584 takes precedence)}
- Y02B 20/30: Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]
- H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- F21K: NON-ELECTRIC LIGHT SOURCES USING LUMINESCENCE; LIGHT SOURCES USING ELECTROCHEMILUMINESCENCE; LIGHT SOURCES USING CHARGES OF COMBUSTIBLE MATERIAL; LIGHT SOURCES USING SEMICONDUCTOR DEVICES AS LIGHT-GENERATING ELEMENTS; LIGHT SOURCES NOT OTHERWISE PROVIDED FOR
- F21Y: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
- H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P)
- Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS

## Abstract

A buck-boost converter may include a first switch, an inductor, a first diode, a second switch, a second diode, and a capacitor. A cathode end of the first diode may be coupled to a first end of the inductor and a second end of the first switch. An anode end of the second diode may be coupled to a second end of the inductor and a first end of the second switch. A second end of the capacitor may be coupled to a second end of the second switch and an anode end of the first diode. A first end of the capacitor may be coupled to a cathode end of the second diode.

## Claims

### Claim 1

A tubular light emitting diode (LED) ballast including a buck-boost converter circuit, comprising:
a first switch having a first end and a second end;
an inductor having a first end and a second end;
a first diode having a cathode end and an anode end, wherein the cathode end of the first diode is coupled to the first end of the inductor and the second end of the first switch;
a second switch having a first end and a second end;
a second diode having a cathode end and an anode end, wherein the anode end of the second diode is coupled to the second end of the inductor and the first end of the second switch; and
a capacitor having a first end and a second end, wherein the second end of the capacitor is coupled to the second end of the second switch and the anode end of the first diode and wherein the first end of the capacitor is coupled to the cathode end of the second diode.

### Claim 2 (depends on 1)

The tubular LED ballast of claim 1, wherein the first switch and the second switch are transistors.

### Claim 3 (depends on 1)

The tubular LED ballast of claim 1, wherein in a first, buck-boost converter mode, the first switch and the second switch are driven by a same input signal.

### Claim 4 (depends on 3)

The tubular LED ballast of claim 3, wherein the first switch and the second switch are driven by a waveform input signal.

### Claim 5 (depends on 3)

The tubular LED ballast of claim 3, wherein first diode and the second diode are freewheeling diodes.

### Claim 6 (depends on 1)

The tubular LED ballast of claim 1, wherein in a second, buck converter mode, the first switch is driven by a waveform input signal and the second switch is open.

### Claim 7 (depends on 6)

The tubular LED ballast of claim 6, wherein first diode is a freewheeling diode.

### Claim 8 (depends on 1)

The tubular LED ballast of claim 1, wherein in a third, boost converter mode, the first switch is closed and the second switch is driven by a waveform input signal.

### Claim 9 (depends on 8)

The tubular LED ballast of claim 8, wherein second diode is a freewheeling diode.

### Claim 10 (depends on 1)

The tubular LED ballast of claim 1, wherein the first switch and the second switch are driven based on a reading associated with the inductor.

### Claim 11 (depends on 1)

The tubular LED ballast of claim 1, wherein the first switch and the second switch are driven based on a rectified AC voltage across the first diode.

### Claim 12 (depends on 1)

The tubular LED ballast of claim 1, wherein the first switch and the second switch are driven based on sensing a DC voltage across the capacitor.

### Claim 13

A tubular light emitting diode (LED) ballast including a buck-boost converter circuit, comprising:
a first switch having a first end and a second end;
a first loop including:
an inductor having a first end and a second end;
a first diode having a cathode end and an anode end, wherein the cathode end of the first diode is coupled to the first end of the inductor and the second end of the first switch; and
a second switch having a first end and a second end; and
a second loop including:
a second diode having a cathode end and an anode end, wherein the anode end of the second diode is coupled to the second end of the inductor and the first end of the second switch;
a capacitor having a first end and a second end, wherein the second end of the capacitor is coupled to the second end of the second switch and the anode end of the first diode and wherein the first end of the capacitor is coupled to the cathode end of the second diode.

### Claim 14 (depends on 13)

The tubular LED ballast of claim 13, wherein in a first, buck-boost converter mode, the first switch and the second switch are driven by a same input signal.

### Claim 15 (depends on 13)

The tubular LED ballast of claim 13, wherein in a second, buck converter mode, the first switch is driven by a waveform input signal and the second switch is open.

### Claim 16 (depends on 13)

The tubular LED ballast of claim 13, wherein in a third, boost converter mode, the first switch is closed and the second switch is driven by a waveform input signal.

### Claim 17

A tubular light emitting diode (LED) ballast including a buck-boost converter circuit, comprising:
a first switch having a first end and a second end;
an inductor having a first end and a second end;
a first diode having a cathode end and an anode end, wherein the cathode end of the first diode is coupled to the first end of the inductor and the second end of the first switch;
a second switch having a first end and a second end;
a second diode having a cathode end and an anode end, wherein the anode end of the second diode is coupled to the second end of the inductor and the first end of the second switch; and
a capacitor having a first end and a second end, wherein the second end of the capacitor is coupled to the second end of the second switch and the anode end of the first diode and wherein the first end of the capacitor is coupled to the cathode end of the second diode,
wherein in a first, buck-boost converter mode, the first switch and the second switch are driven by a waveform input signal,
wherein in a second, buck converter mode, the first switch is driven by the waveform input signal and the second switch is open, and
wherein in a third, boost converter mode, the first switch is closed and the second switch is driven by the waveform input signal.

### Claim 18 (depends on 17)

The tubular LED ballast of claim 17, wherein the first switch and the second switch are driven based on a reading associated with the inductor.

### Claim 19 (depends on 17)

The tubular LED ballast of claim 17, wherein the first switch and the second switch are driven based on a rectified AC voltage across the first diode.

### Claim 20 (depends on 17)

The tubular LED ballast of claim 17, wherein the first switch and the second switch are driven based on sensing a DC voltage across the capacitor.