# US 2018/0324918 A1 · Driving circuit and lighting apparatus for light emitting diode

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- Number: US 2018/0324918 A1
- Document ID: US20180324918A1
- Status: Published application
- Kind: A1
- Application number: 16/039,345
- Filed: 2018-07-19
- Published: 2018-11-08
- Earliest claimed: 2015-08-21
- Assignees: Seoul Semiconductor Co., Ltd.
- Applicants: Seoul Semiconductor Co., Ltd.
- Inventors: Kwang Bea LIM; Sung Ho JIN; Sang Wook HAN; Young Do JONG
- Web page: https://patentgrep.com/patent/US20180324918A1

## CPC

- H05B 45/48: having LEDs organised in strings and incorporating parallel shunting devices
- H05B 45/10: Controlling the intensity of the light
- H05B 45/31: Phase-control circuits
- H05B 45/3575: by means of dummy loads or bleeder circuits, e.g. for dimmers
- H05B 45/36: Circuits for reducing or suppressing harmonics, ripples or electromagnetic interferences [EMI]
- H05B 47/14: by determining electrical parameters of the light source
- H05B 47/16: by timing means
- H05B 45/325: Pulse-width modulation [PWM]
- H05B 45/345: Current stabilisation; Maintaining constant current
- Y02B 20/40: Control techniques providing energy savings, e.g. smart controller or presence detection
- H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS

## Abstract

A lighting apparatus including a light emitting diode connected to a dimmer configured to modulate an input AC voltage depending on a selected dimming level, a rectifier configured to full-wave rectify the modulated AC voltage output from the dimmer to generate and output a driving voltage, a driving module configured to receive the driving voltage of the rectifier to detect the selected dimming level, and select one of three driving modes of a stop mode, a resistance driving mode, and a sequential driving mode depending on the detected dimming level, and a plurality of light emitting diode groups configured to emit light depending on a control of the driving module.

## Claims

### Claim 1

A lighting apparatus comprising:
a light emitting diode connected to a dimmer configured to modulate an input AC voltage depending on a selected dimming level;
a rectifier configured to full-wave rectify the modulated AC voltage output from the dimmer to generate and output a driving voltage;
a driving module configured to receive the driving voltage of the rectifier to detect the selected dimming level, and select one of three driving modes of a stop mode, a resistance driving mode, and a sequential driving mode depending on the detected dimming level; and
a plurality of light emitting diode groups configured to emit light depending on a control of the driving module.

### Claim 2 (depends on 1)

The lighting apparatus of claim 1, wherein the stop mode corresponds to a first dimming level equal to or less than 1° to 30°.

### Claim 3 (depends on 1)

The lighting apparatus of claim 1, wherein the resistance driving mode corresponds to a second dimming level in the range of 31° to 90°.

### Claim 4 (depends on 1)

The lighting apparatus of claim 1, wherein the sequential driving mode corresponds to a third dimming level in the range of 91° to 180°.

### Claim 5 (depends on 1)

The lighting apparatus claim 1, wherein:
the driving module comprises a dimming level detector configured to detect the dimming level; and
the dimming level detector comprises:
a first resistor and a second resistor connected to a mode terminal;
a first capacitor connected between the first and second resistors in parallel; and
a second capacitor connected to an internal DC power terminal.

### Claim 6 (depends on 5)

The lighting apparatus of claim 5, wherein the dimming level detector comprises a third resistor and a capacitor to detect a signal section modulated by the dimmer by using a clock signal of the driving module.

### Claim 7 (depends on 1)

The lighting apparatus claim 1, wherein the dimmer comprises one of a TRIAC dimmer configured to phase-cut a phase of AC power using a TRIAC, a pulse width modulation (PWM) dimmer, and an analog voltage dimmer configured to change the AC voltage.

### Claim 8 (depends on 1)

The lighting apparatus of claim 1, further comprising a bleeder circuit to provide a bleeder current to the dimmer,
wherein the bleeder circuit is configured to detect a driving current of for the light emitting diode flowing through at least one of the plurality of light emitting diode groups, and control the magnitude of the bleeder current based on the detected driving current for the light emitting diode.

### Claim 9 (depends on 8)

The lighting apparatus of claim 8, wherein the bleeder circuit is configured to not provide the bleeder current when the detected dimming level is equal to or greater than a preset threshold dimming level.

### Claim 10 (depends on 8)

The lighting apparatus of claim 8, wherein:
the bleeder circuit is configured to control the magnitude of the bleeder current to maintain a sum of the driving current for the light emitting diode and the bleeder current at a preset threshold current value; and
the threshold current value is equal to or greater than a holding current value of the dimmer.