TWI707607B - LED driving circuit and LED lamps using it - Google Patents

LED driving circuit and LED lamps using it Download PDF

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TWI707607B
TWI707607B TW108134940A TW108134940A TWI707607B TW I707607 B TWI707607 B TW I707607B TW 108134940 A TW108134940 A TW 108134940A TW 108134940 A TW108134940 A TW 108134940A TW I707607 B TWI707607 B TW I707607B
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voltage
led
current
sensing
circuit
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TW202114468A (en
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賈有平
程志強
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大陸商北京集創北方科技股份有限公司
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
    • Y02B20/30—Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

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Abstract

一種LED驅動電路，其特徵在於具有：一第一分壓電路，用以依一輸入電壓提供一第一感測電壓；以及一檢測電路，具有一感測單元及一可禁能之電流源，該感測單元係用以檢測該第一感測電壓低於一第一參考電壓的時間是否超過一閾值以決定一致能信號的狀態，若是，則使該致能信號呈現一作用狀態以致能該可禁能之電流源，若否，則使該致能信號呈現一不作用狀態以禁能該可禁能之電流源，且該可禁能之電流源在被致能時能夠適應性地調整其吸入電流的電流值以使該吸入電流和通過一LED指示燈之一預定電流相等。 An LED driving circuit, characterized by having: a first voltage divider circuit for providing a first sensing voltage according to an input voltage; and a detection circuit having a sensing unit and a disableable current source The sensing unit is used to detect whether the time when the first sensing voltage is lower than a first reference voltage exceeds a threshold to determine the state of the enabling signal, and if so, to make the enabling signal present an active state to enable The disableable current source, if not, makes the enable signal present a non-active state to disable the disableable current source, and the disableable current source can be adaptively enabled when it is enabled The current value of the suction current is adjusted so that the suction current is equal to a predetermined current through an LED indicator.

Description

LED驅動電路及利用其之LED燈具LED driving circuit and LED lamps using it

本發明係有關一種LED驅動電路，尤指一種可和帶有指示燈之開關面板搭配之LED驅動電路。The present invention relates to an LED drive circuit, especially an LED drive circuit that can be matched with a switch panel with indicator lights.

在用以開關照明燈具的現有開關面板中，為了方便使用者在燈關掉之後找到開關面板的位置，有的開關面板會靠表面螢光粉來提供微弱反光，有的則在面板內嵌一個LED小夜燈，面板閉合小夜燈不亮，面板關斷小夜燈亮。In the existing switch panels used to switch lighting fixtures, in order to facilitate the user to find the position of the switch panel after the light is turned off, some switch panels rely on surface phosphor to provide weak reflection, and some are embedded in the panel. LED night light, the panel is closed, the night light is off, and the panel is off, the night light is on.

請參照圖1，其繪示一習知照明燈具之電路圖。如圖1所示，該習知照明燈具包含一開關11、一LED 12、由四個二極體(13a、13b、13c、13d)組成之一全波整流單元13、一濾波電容14、一檢測電路15、一二極體16、一電感17、一驅動器18及一LED模組19，其中，檢測電路15具有由電阻15a和電阻15b組成之一分壓電路以提供一第一控制電壓V 1，由電阻15c和雙極性接面電晶體15d所組成之一第一反相電路以依第一控制電壓V 1產生與其反相之一第二控制電壓V 2，以及由電阻15e和雙極性接面電晶體15f所組成之一第二反相電路以在第二控制電壓V 2為高電位時為LED 12提供一電流路徑；二極體16、電感17和驅動器18則形成一驅動電路以驅動LED模組19。 Please refer to Figure 1, which shows a circuit diagram of a conventional lighting fixture. As shown in Figure 1, the conventional lighting fixture includes a switch 11, an LED 12, a full-wave rectifier unit 13 composed of four diodes (13a, 13b, 13c, 13d), a filter capacitor 14, a The detection circuit 15, a diode 16, an inductor 17, a driver 18, and an LED module 19, wherein the detection circuit 15 has a voltage divider circuit composed of a resistor 15a and a resistor 15b to provide a first control voltage V 1 , a first inverter circuit composed of a resistor 15c and a bipolar junction transistor 15d to generate a second control voltage V 2 that is inverted from the first control voltage V 1 , and a resistor 15e and a double A second inverter circuit formed by the polar junction transistor 15f provides a current path for the LED 12 when the second control voltage V 2 is high; the diode 16, the inductor 17 and the driver 18 form a driving circuit To drive the LED module 19.

當開關11閉合時：和開關11並聯的LED 12(小夜燈)不亮；全波整流單元13對交流電壓V AC進行全波整流以產生一輸入電壓V IN以供所述的驅動電路點亮LED模組19；且此時第一控制電壓V 1為高電位，第二控制電壓V 2為低電位，雙極性接面電晶體15f為關斷狀態。當開關11關斷時：和開關11並聯的LED 12(小夜燈)點亮；濾波電容14上的輸入電壓V IN的準位會大幅下降，致使所述的驅動電路無法點亮LED模組19；且此時第一控制電壓V 1為低電位，第二控制電壓V 2為高電位，雙極性接面電晶體15f為閉合狀態以為LED 12提供一電流路徑。 When the switch 11 is closed: the LED 12 (night light) in parallel with the switch 11 does not light; the full-wave rectifier unit 13 performs full-wave rectification on the AC voltage V AC to generate an input voltage V IN for the driving circuit to light up LED module 19; and at this time, the first control voltage V 1 is at a high potential, the second control voltage V 2 is at a low potential, and the bipolar junction transistor 15f is in the off state. When the switch 11 is turned off: the LED 12 (night light) connected in parallel with the switch 11 lights up; the level of the input voltage V IN on the filter capacitor 14 will drop significantly, causing the drive circuit to fail to light the LED module 19 ; And at this time, the first control voltage V 1 is a low potential, the second control voltage V 2 is a high potential, and the bipolar junction transistor 15f is in a closed state to provide a current path for the LED 12.

另外，考慮到系統成本和硬體空間的限制，濾波電容14一般不會選取特別大的電容值。然而，由於市電一般會有相當大的電壓變動範圍，例如100V的交流市電會在AC 85V~115V之間變動，因此，當開關11閉合且交流市電處於比較低的電壓時，輸入電壓V IN的波谷位置會比較低，致使第一控制電壓V 1可能會小於雙極性接面電晶體15d的導通電壓而使雙極性接面電晶體15f導通，從而分走了LED模組19的電流並因而降低了該習知照明燈具的工作效率。另外，雙極性接面電晶體15d和雙極性接面電晶體15f均為高壓元件，無論是以離散元件的方式實現或是集成到晶片內部，都有成本偏高的缺點。 In addition, considering the system cost and hardware space constraints, the filter capacitor 14 generally does not select a particularly large capacitance value. However, since the commercial power generally has a considerable voltage fluctuation range, for example, 100V AC mains will vary between AC 85V and 115V. Therefore, when the switch 11 is closed and the AC mains is at a relatively low voltage, the input voltage V IN The trough position will be relatively low, so that the first control voltage V 1 may be less than the turn-on voltage of the bipolar junction transistor 15d and the bipolar junction transistor 15f will be turned on, thereby dividing the current of the LED module 19 and reducing it The work efficiency of the conventional lighting fixture is improved. In addition, the bipolar junction transistor 15d and the bipolar junction transistor 15f are both high-voltage components. Whether implemented as discrete components or integrated into the chip, they have the disadvantage of high cost.

為解決上述問題，本領域亟需一種新穎的LED驅動電路。In order to solve the above problems, a novel LED driving circuit is urgently needed in the art.

本發明之一目的在於提供一種LED驅動電路，其可在不影響一LED模組的驅動效率的情況下為一開關面板的LED指示燈適應性地提供一電流路徑，以在該開關面板之一開關被斷開時點亮該LED指示燈。An object of the present invention is to provide an LED driving circuit, which can adaptively provide a current path for the LED indicator of a switch panel without affecting the driving efficiency of an LED module, so that the This LED indicator will light up when the switch is turned off.

本發明之另一目的在於提供一種LED燈具，其可在不影響其內部之一LED模組的驅動效率的情況下為與其搭配之一開關面板的LED指示燈適應性地提供一電流路徑，以在該開關面板之一開關被斷開時點亮該LED指示燈。Another object of the present invention is to provide an LED lamp, which can adaptively provide a current path for the LED indicator of a switch panel without affecting the driving efficiency of one of its internal LED modules. The LED indicator light is lit when one of the switches of the switch panel is turned off.

為達到前述之目的，一種LED驅動電路乃被提出，其係用以和一開關面板搭配以驅動一LED模組，該開關面板包含一開關及和該開關並聯之一LED指示燈，當該開關閉合時，該LED驅動電路依一輸入電壓產生一輸出電流以驅動該LED模組，當該開關斷開時，該LED驅動電路提供一電流路徑以點亮該LED指示燈，該LED驅動電路的特徵在於具有：In order to achieve the aforementioned purpose, an LED driving circuit is proposed, which is used with a switch panel to drive an LED module. The switch panel includes a switch and an LED indicator parallel to the switch. When the switch When closed, the LED drive circuit generates an output current according to an input voltage to drive the LED module. When the switch is open, the LED drive circuit provides a current path to light up the LED indicator. It is characterized by:

一第一分壓電路，用以依一輸入電壓提供一第一感測電壓；以及A first voltage divider circuit for providing a first sensing voltage according to an input voltage; and

一檢測電路，具有一感測單元及一可禁能之電流源，該感測單元係用以檢測該第一感測電壓低於一第一參考電壓的時間是否超過一閾值以決定一致能信號的狀態，若是，則使該致能信號呈現一作用狀態以致能該可禁能之電流源，若否，則使該致能信號呈現一不作用狀態以禁能該可禁能之電流源，且該可禁能之電流源在被致能時能夠適應性地調整其吸入電流的電流值以使該吸入電流和通過該LED指示燈之一預定電流相等。A detection circuit having a sensing unit and a disableable current source, the sensing unit is used to detect whether the first sensing voltage is lower than a first reference voltage for a time exceeding a threshold to determine an enabling signal If it is, then the enable signal is made to assume an active state to enable the disableable current source, if not, the enable signal is made to assume a non-active state to disable the disableable current source, In addition, when the disabled current source is enabled, the current value of the suction current can be adjusted adaptively to make the suction current equal to a predetermined current through the LED indicator.

在一實施例中，該第一分壓電路係一串聯電阻電路。In one embodiment, the first voltage divider circuit is a series resistance circuit.

在一實施例中，該感測單元具有：In an embodiment, the sensing unit has:

一比較器，用以對該第一感測電壓和該第一參考電壓進行一電壓比較運算以產生一比較結果信號，當該第一感測電壓大於該第一參考電壓時，該比較結果信號呈現一低電位，當該第一感測電壓小於該第一參考電壓時，該比較結果信號呈現一高電位；A comparator for performing a voltage comparison operation on the first sensing voltage and the first reference voltage to generate a comparison result signal. When the first sensing voltage is greater than the first reference voltage, the comparison result signal Presents a low potential, and when the first sensing voltage is less than the first reference voltage, the comparison result signal presents a high potential;

一計時電路，用以在該比較結果信號呈現所述高電位的時間超過該閾值時使一計時輸出信號呈現所述高電位；以及A timing circuit for making a timing output signal present the high potential when the time during which the comparison result signal presents the high potential exceeds the threshold; and

一反及閘，用以對該比較結果信號及該計時輸出信號進行一反及邏輯運算以產生所述的致能信號。An inversion gate is used for performing an inversion logic operation on the comparison result signal and the timing output signal to generate the enabling signal.

在一實施例中，該可禁能之電流源具有：In one embodiment, the disableable current source has:

一JFET電晶體，具有一閘極、一汲極和一源極，該閘極耦接一參考地，該汲極耦接該輸入電壓；A JFET transistor having a gate, a drain and a source, the gate is coupled to a reference ground, and the drain is coupled to the input voltage;

一第二分壓電路，用以依該JFET電晶體的所述源極的電壓產生一第二感測電壓；A second voltage divider circuit for generating a second sensing voltage according to the voltage of the source of the JFET transistor;

一放大器， 具有一致能控制端、一正輸入端、一負輸入端及一輸出端，該致能控制端耦接所述的致能信號，該正輸入端耦接該第二感測電壓，該負輸入端耦接一第二參考電壓；以及An amplifier having a consistent energy control terminal, a positive input terminal, a negative input terminal and an output terminal, the enable control terminal is coupled to the enable signal, and the positive input terminal is coupled to the second sensing voltage, The negative input terminal is coupled to a second reference voltage; and

一NMOS電晶體，具有一閘極以耦接該放大器之所述輸出端，一汲極以耦接該JFET電晶體之所述源極，及一源極以耦接該參考地。An NMOS transistor has a gate for coupling to the output terminal of the amplifier, a drain for coupling to the source of the JFET transistor, and a source for coupling to the reference ground.

在一實施例中，該輸入電壓係一交流電壓經一全波整流單元整流後所產生的電壓。In one embodiment, the input voltage is a voltage generated after an AC voltage is rectified by a full-wave rectifier unit.

為達到前述之目的，本發明進一步提出一種LED燈具，其包括一LED驅動電路及一LED模組，其中，該LED驅動電路係用以和一開關面板搭配以驅動該LED模組，該開關面板包含一開關及和該開關並聯之一LED指示燈，當該開關閉合時，該LED驅動電路依一輸入電壓產生一輸出電流以驅動該LED模組，當該開關斷開時，該LED驅動電路提供一電流路徑以點亮該LED指示燈，該LED驅動電路的特徵在於具有：In order to achieve the foregoing objective, the present invention further provides an LED lamp, which includes an LED driving circuit and an LED module, wherein the LED driving circuit is used with a switch panel to drive the LED module, and the switch panel It includes a switch and an LED indicator in parallel with the switch. When the switch is closed, the LED drive circuit generates an output current according to an input voltage to drive the LED module. When the switch is off, the LED drive circuit A current path is provided to light the LED indicator, and the LED drive circuit is characterized by:

一第一分壓電路，用以依一輸入電壓提供一第一感測電壓；以及A first voltage divider circuit for providing a first sensing voltage according to an input voltage; and

一檢測電路，具有一感測單元及一可禁能之電流源，該感測單元係用以檢測該第一感測電壓低於一第一參考電壓的時間是否超過一閾值以決定一致能信號的狀態，若是，則使該致能信號呈現一作用狀態以致能該可禁能之電流源，若否，則使該致能信號呈現一不作用狀態以禁能該可禁能之電流源，且該可禁能之電流源在被致能時能夠適應性地調整其吸入電流的電流值以使該吸入電流和通過該LED指示燈之一預定電流相等。A detection circuit having a sensing unit and a disableable current source, the sensing unit is used to detect whether the first sensing voltage is lower than a first reference voltage for a time exceeding a threshold to determine an enabling signal If it is, then the enable signal is made to assume an active state to enable the disableable current source, if not, the enable signal is made to assume a non-active state to disable the disableable current source, In addition, when the disabled current source is enabled, the current value of the suction current can be adjusted adaptively to make the suction current equal to a predetermined current through the LED indicator.

在一實施例中，該第一分壓電路係一串聯電阻電路。In one embodiment, the first voltage divider circuit is a series resistance circuit.

在一實施例中，該感測單元具有：In an embodiment, the sensing unit has:

一比較器，用以對該第一感測電壓和該第一參考電壓進行一電壓比較運算以產生一比較結果信號，當該第一感測電壓大於該第一參考電壓時，該比較結果信號呈現一低電位，當該第一感測電壓小於該第一參考電壓時，該比較結果信號呈現一高電位；A comparator for performing a voltage comparison operation on the first sensing voltage and the first reference voltage to generate a comparison result signal. When the first sensing voltage is greater than the first reference voltage, the comparison result signal Presents a low potential, and when the first sensing voltage is less than the first reference voltage, the comparison result signal presents a high potential;

一計時電路，用以在該比較結果信號呈現所述高電位的時間超過該閾值時使一計時輸出信號呈現所述高電位；以及A timing circuit for making a timing output signal present the high potential when the time during which the comparison result signal presents the high potential exceeds the threshold; and

一反及閘，用以對該比較結果信號及該計時輸出信號進行一反及邏輯運算以產生所述的致能信號。An inversion gate is used for performing an inversion logic operation on the comparison result signal and the timing output signal to generate the enabling signal.

在一實施例中，該可禁能之電流源具有：In one embodiment, the disableable current source has:

一JFET電晶體，具有一閘極、一汲極和一源極，該閘極耦接一參考地，該汲極耦接該輸入電壓；A JFET transistor having a gate, a drain and a source, the gate is coupled to a reference ground, and the drain is coupled to the input voltage;

一第二分壓電路，用以依該JFET電晶體的所述源極的電壓產生一第二感測電壓；A second voltage divider circuit for generating a second sensing voltage according to the voltage of the source of the JFET transistor;

一放大器， 具有一致能控制端、一正輸入端、一負輸入端及一輸出端，該致能控制端耦接所述的致能信號，該正輸入端耦接該第二感測電壓，該負輸入端耦接一第二參考電壓；以及An amplifier having a consistent energy control terminal, a positive input terminal, a negative input terminal and an output terminal, the enable control terminal is coupled to the enable signal, and the positive input terminal is coupled to the second sensing voltage, The negative input terminal is coupled to a second reference voltage; and

一NMOS電晶體，具有一閘極以耦接該放大器之所述輸出端，一汲極以耦接該JFET電晶體之所述源極，及一源極以耦接該參考地。An NMOS transistor has a gate for coupling to the output terminal of the amplifier, a drain for coupling to the source of the JFET transistor, and a source for coupling to the reference ground.

在一實施例中，該輸入電壓係一交流電壓經一全波整流單元整流後所產生的電壓。In one embodiment, the input voltage is a voltage generated after an AC voltage is rectified by a full-wave rectifier unit.

請參照圖2，其繪示本發明之照明燈具之一實施例之電路圖。如圖2所示，一LED燈具100係與一開關面板110(包含一開關110a及和開關110a並聯之一LED 110b)耦接，其中，LED燈具100包含一全波整流單元101、一濾波電容102、一分壓電路103(由一第一電阻103a和一第二電阻103b串接而成)、一檢測電路104、一驅動電路105(包含一二極體105a、一電感105b和一驅動器105c)以及一LED模組106，其中，檢測電路104具有一比較器104a、一計時電路104b、一反及閘104c、一第三電阻104d、一第四電阻104e、一放大器104f、一NMOS電晶體104g及一JFET電晶體104h，其中，比較器104a、計時電路104b及反及閘104c組成一感測單元，第三電阻104d、第四電阻104e、放大器104f、NMOS電晶體104g及JFET電晶體104h組成一可禁能之電流源，該感測單元係用以在分壓電路103所提供之一第一感測電壓V 1低於一第一參考電壓V REF1的時間超過一閾值(例如但不限於10ms)時使其輸出之一致能信號EN呈現一作用狀態(例如但不限於一高電位)，且該可禁能之電流源在致能信號EN呈現所述作用狀態時能夠適應性地調整其吸入電流的電流值，以使該吸入電流等於開關面板110上預定通過LED 110b之一驅動電流，以穩定點亮LED 110b。 Please refer to FIG. 2, which shows a circuit diagram of an embodiment of the lighting fixture of the present invention. As shown in FIG. 2, an LED lamp 100 is coupled to a switch panel 110 (including a switch 110a and an LED 110b connected in parallel with the switch 110a), wherein the LED lamp 100 includes a full-wave rectifier unit 101 and a filter capacitor 102. A voltage divider circuit 103 (consisting of a first resistor 103a and a second resistor 103b connected in series), a detection circuit 104, a driving circuit 105 (including a diode 105a, an inductor 105b and a driver 105c) and an LED module 106, wherein the detection circuit 104 has a comparator 104a, a timing circuit 104b, an inverter 104c, a third resistor 104d, a fourth resistor 104e, an amplifier 104f, and an NMOS circuit The crystal 104g and a JFET transistor 104h, wherein the comparator 104a, the timing circuit 104b and the inverter 104c constitute a sensing unit, the third resistor 104d, the fourth resistor 104e, the amplifier 104f, the NMOS transistor 104g and the JFET transistor 104h constitutes a disableable current source, and the sensing unit is used for a first sensing voltage V 1 provided by the voltage divider circuit 103 to be lower than a first reference voltage V REF1 for a time exceeding a threshold (for example But not limited to 10ms), the output of the enabling signal EN presents an active state (for example, but not limited to a high potential), and the disableable current source is adaptable when the enable signal EN presents the active state The current value of the sink current is adjusted to make the sink current equal to the drive current scheduled to pass through one of the LEDs 110b on the switch panel 110 to stably light the LED 110b.

當開關110a閉合時：和開關110a並聯的LED 110b (小夜燈)不亮；全波整流單元101對交流電壓V AC進行全波整流以產生一輸入電壓V IN以供驅動電路105點亮LED模組106；在此情況下，第一感測電壓V 1低於第一參考電壓V REF1的時間不會超過該閾值，致能信號EN會呈現一不作用狀態(例如但不限於一低電位)，且NMOS電晶體104g呈現關斷狀態。 When the switch 110a is closed: the LED 110b (night light) in parallel with the switch 110a does not light; the full-wave rectifier unit 101 performs full-wave rectification on the AC voltage V AC to generate an input voltage V IN for the driving circuit 105 to light the LED module Group 106; in this case, the time that the first sensing voltage V 1 is lower than the first reference voltage V REF1 will not exceed the threshold, and the enabling signal EN will assume an inactive state (such as but not limited to a low potential) , And the NMOS transistor 104g is in an off state.

當開關110a關斷時：和開關110a並聯的LED 110b (小夜燈)點亮；濾波電容102上的輸入電壓V IN的準位會大幅下降，致使驅動電路105無法點亮LED模組106；在此情況下，第一感測電壓V 1低於第一參考電壓V REF1的時間會超過該閾值，致能信號EN會呈現所述的作用狀態以致能該可禁能之電流源。 When the switch 110a is turned off: the LED 110b (night light) in parallel with the switch 110a lights up; the level of the input voltage V IN on the filter capacitor 102 will drop significantly, causing the driving circuit 105 to fail to light the LED module 106; In this case, the time that the first sensing voltage V 1 is lower than the first reference voltage V REF1 will exceed the threshold, and the enabling signal EN will assume the above-mentioned active state to enable the disableable current source.

具體而言，該感測單元的工作原理說明如下：Specifically, the working principle of the sensing unit is described as follows:

比較器104a係用以對第一感測電壓V 1和第一參考電壓V REF1進行一電壓比較運算以產生一比較結果信號，當第一感測電壓V 1大於第一參考電壓V REF1時，該比較結果信號呈現一低電位，當第一感測電壓V 1小於第一參考電壓V REF1時，該比較結果信號呈現一高電位； The comparator 104a is used to perform a voltage comparison operation on the first sensing voltage V 1 and the first reference voltage V REF1 to generate a comparison result signal. When the first sensing voltage V 1 is greater than the first reference voltage V REF1 , The comparison result signal presents a low potential, and when the first sensing voltage V 1 is less than the first reference voltage V REF1 , the comparison result signal presents a high potential;

計時電路104b係用以在該比較結果信號呈現所述高電位的時間超過該閾值時使一計時輸出信號呈現所述高電位；The timing circuit 104b is used to make a timing output signal exhibit the high potential when the time for the comparison result signal to exhibit the high potential exceeds the threshold;

反及閘104c係用以對該比較結果信號及該計時輸出信號進行一反及邏輯運算以產生致能信號EN。The inversion gate 104c is used to perform an inversion logic operation on the comparison result signal and the timing output signal to generate an enable signal EN.

該可禁能之電流源之工作原理說明如下：The working principle of this disableable current source is explained as follows:

第三電阻104d和第四電阻104e組成一分壓電路以依JFET電晶體104h的源極電壓V X產生一第二感測電壓V 2； The third resistor 104d and the fourth resistor 104e form a voltage divider circuit to generate a second sensing voltage V 2 according to the source voltage V X of the JFET transistor 104h;

放大器104f 具有一致能控制端、一正輸入端、一負輸入端及一輸出端，該致能控制端耦接致能信號EN，該正輸入端耦接第二感測電壓V 2，該負輸入端耦接第二參考電壓V REF2，且該輸出端耦接NMOS電晶體104g； The amplifier 104f has an enabling control terminal, a positive input terminal, a negative input terminal, and an output terminal. The enable control terminal is coupled to the enable signal EN, the positive input terminal is coupled to the second sensing voltage V 2 , and the negative The input terminal is coupled to the second reference voltage V REF2 , and the output terminal is coupled to the NMOS transistor 104g;

NMOS電晶體104g具有一閘極、一汲極和一源極，該閘極耦接放大器104f之所述輸出端，該汲極耦接JFET電晶體104h，且該源極耦接一參考地；The NMOS transistor 104g has a gate, a drain and a source, the gate is coupled to the output terminal of the amplifier 104f, the drain is coupled to the JFET transistor 104h, and the source is coupled to a reference ground;

JFET電晶體104h具有一閘極、一汲極和一源極，該閘極耦接所述的參考地，該汲極耦接輸入電壓V IN，且該源極耦接NMOS電晶體104g的所述汲極。 The JFET transistor 104h has a gate, a drain and a source, the gate is coupled to the reference ground, the drain is coupled to the input voltage V IN , and the source is coupled to all of the NMOS transistor 104g Described very much.

當致能信號EN呈現所述作用狀態時，放大器104f會被致能，從而致能由放大器104f、NMOS電晶體104g、第三電阻104d和第四電阻104e所形成的一負回授電路以使JFET電晶體104h的吸入電流能夠適應性地調整為LED 110b的額定電流。When the enable signal EN assumes the above-mentioned active state, the amplifier 104f will be enabled, thereby enabling a negative feedback circuit formed by the amplifier 104f, the NMOS transistor 104g, the third resistor 104d and the fourth resistor 104e to make The sink current of the JFET transistor 104h can be adaptively adjusted to the rated current of the LED 110b.

請參考圖3，其繪示圖2之照明燈具之一工作波形圖。如圖3所示，當第一感測電壓V 1低於第一參考電壓V REF1的時間不超過閾值T S(10 ms)時，致能信號EN會呈現所述的不作用狀態(低電位)—代表開關110a閉合；當第一感測電壓V 1低於第一參考電壓V REF1的時間超過閾值T S(10 ms)時，致能信號EN會呈現所述的作用狀態(高電位)—代表開關110a斷開。 Please refer to Figure 3, which shows a working waveform diagram of one of the lighting fixtures in Figure 2. As shown in FIG. 3, when the first sensing voltage V 1 is lower than the first reference voltage V REF1 for a time that does not exceed the threshold T S (10 ms), the enable signal EN will assume the inactive state (low potential ) - denotes a switch 110a is closed; the time when the first sensing voltage V 1 is lower than the first reference voltage V REF1 exceeds a threshold value T S (10 ms), the enable signal EN will exhibit active state (the high potential) -Represents that the switch 110a is off.

另外，由於經全波整流單元101整流後的輸入電壓V IN屬於高電壓，因此JFET電晶體104h須採用高壓元件。 In addition, since the input voltage V IN rectified by the full-wave rectification unit 101 is a high voltage, the JFET transistor 104h must use a high-voltage component.

另外，JFET電晶體104h在功能上相當於一個電阻。由於不同型號的開關面板的小夜燈額定電流並不相同，所以小夜燈的驅動電路不能設置成固定電流。依上述的設計，當致能信號EN信號呈現所述的作用狀態時，如果LED 110b的額定電流大於該可禁能之電流源的吸收電流，則JFET電晶體104h的源極電壓V X會升高，致使第二感測電壓V 2升高以增加該可禁能之電流源的吸收電流；反之，如果LED 110b的額定電流小於該可禁能之電流源的吸收電流，則JFET電晶體104h的源極電壓V X會下降，致使第二感測電壓V 2下降以減少該可禁能之電流源的吸收電流，最終達到一個動態平衡。 In addition, the JFET transistor 104h is functionally equivalent to a resistor. Since the rated current of the night light of different types of switch panels is different, the drive circuit of the night light cannot be set to a fixed current. According to the above design, when the enable signal EN signal presents the stated action state, if the rated current of the LED 110b is greater than the absorption current of the disableable current source, the source voltage V X of the JFET transistor 104h will increase High, causing the second sensing voltage V 2 to increase to increase the absorption current of the disableable current source; conversely, if the rated current of the LED 110b is less than the absorption current of the disableable current source, the JFET transistor 104h The source voltage V X of V will drop, causing the second sensing voltage V 2 to drop to reduce the absorption current of the disable current source, and finally a dynamic balance is achieved.

另外，JFET電晶體104h亦可為檢測電路104提供電源通路以產生內部電源、第一參考電壓V REF1和第二參考電壓V REF2。 In addition, the JFET transistor 104h can also provide a power path for the detection circuit 104 to generate internal power, the first reference voltage V REF1 and the second reference voltage V REF2 .

依上述的說明可知，本發明可提供以下的優點：According to the above description, the present invention can provide the following advantages:

1. LED燈具效率高。1. LED lamps have high efficiency.

本發明的檢測電路即使在整流後的輸入電壓有比較低的波谷，但若該輸入電壓時間低於一參考電壓的時間未超過一閾值（約10mS），會認為開關面板沒有關斷，就不會啟動小夜燈的驅動電路，因而不會流失多餘的功耗。Even though the rectified input voltage of the detection circuit of the present invention has a relatively low trough, if the input voltage time is lower than a reference voltage for a time period that does not exceed a threshold value (about 10mS), it will be considered that the switch panel is not turned off, so The drive circuit of the night light will be activated, so excess power consumption will not be lost.

2.便於集成到晶片內部，系統成本低。2. It is easy to integrate into the chip, and the system cost is low.

本發明的檢測電路只使用了一個便於集成到驅動器晶片內部的高壓元件JFET電晶體104h，既節省了硬體空間，又降低系統的應用成本。另外，JFET電晶體104h也可以作為驅動器晶片的啟動電阻，因此無需用到額外的啟動電阻，簡化了系統設計。The detection circuit of the present invention only uses a high-voltage element JFET transistor 104h that is easy to integrate into the driver chip, which not only saves hardware space, but also reduces the application cost of the system. In addition, the JFET transistor 104h can also be used as the startup resistor of the driver chip, so no additional startup resistor is needed, which simplifies the system design.

本發明所揭示者，乃較佳實施例之一種，舉凡局部之變更或修飾而源於本發明之技術思想而為熟習該項技藝知人所易於推知者，俱不脫本發明之專利權範疇。The disclosure of the present invention is one of the preferred embodiments, and any partial changes or modifications that are derived from the technical ideas of the present invention and are easily inferred by those skilled in the art will not depart from the scope of the patent right of the present invention.

綜上所陳，本案無論目的、手段與功效，皆顯示其迥異於習知技術，且其首先發明合於實用，確實符合發明之專利要件，懇請　貴審查委員明察，並早日賜予專利俾嘉惠社會，是為至禱。In summary, regardless of the purpose, means and effect of this case, it is shown that it is very different from the conventional technology, and its first invention is suitable for practicality, and it does meet the patent requirements of the invention. I implore the examiner to investigate and grant the patent as soon as possible Society is for the best prayer.

11:開關 12:LED 13:全波整流單元 13a、13b、13c、13d:二極體 14:濾波電容 15:檢測電路 15a、15b、15c、15e:電阻 15d、15f:雙極性接面電晶體 16:二極體 17:電感 18:驅動器 19:LED模組 100:LED燈具 101:全波整流單元 102:濾波電容 103:分壓電路 103a:第一電阻 103b:第二電阻 104:檢測電路 104a:比較器 104b:計時電路 104c:反及閘 104d:第三電阻 104e:第四電阻 104f:放大器 104g:NMOS電晶體 104h:JFET電晶體 105:驅動電路 105a:二極體 105b:電感 105c:驅動器 106:LED模組 110:開關面板 110a:開關 110b:LED 11: switch 12: LED 13: Full-wave rectifier unit 13a, 13b, 13c, 13d: diode 14: filter capacitor 15: Detection circuit 15a, 15b, 15c, 15e: resistance 15d, 15f: bipolar junction transistor 16: Diode 17: Inductance 18: drive 19: LED module 100: LED lamps 101: Full-wave rectifier unit 102: filter capacitor 103: Voltage divider circuit 103a: first resistor 103b: second resistor 104: detection circuit 104a: Comparator 104b: Timing circuit 104c: reverse and gate 104d: third resistor 104e: fourth resistor 104f: amplifier 104g: NMOS transistor 104h: JFET transistor 105: drive circuit 105a: Diode 105b: Inductance 105c: drive 106: LED module 110: switch panel 110a: switch 110b: LED

圖1繪示一習知照明燈具之電路圖。 圖2繪示本發明之照明燈具之一實施例之電路圖。 圖3繪示圖2之照明燈具之一工作波形圖。 Figure 1 shows a circuit diagram of a conventional lighting fixture. Fig. 2 is a circuit diagram of an embodiment of the lighting fixture of the present invention. Fig. 3 shows a working waveform diagram of the lighting fixture of Fig. 2;

100:LED燈具 100: LED lamps

101:全波整流單元 101: Full-wave rectifier unit

102:濾波電容 102: filter capacitor

103:分壓電路 103: Voltage divider circuit

103a:第一電阻 103a: first resistor

103b:第二電阻 103b: second resistor

104:檢測電路 104: detection circuit

104a:比較器 104a: Comparator

104b:計時電路 104b: Timing circuit

104c:反及閘 104c: reverse and gate

104d:第三電阻 104d: third resistor

104e:第四電阻 104e: fourth resistor

104f:放大器 104f: amplifier

104g:NMOS電晶體 104g: NMOS transistor

104h:JFET電晶體 104h: JFET transistor

105:驅動電路 105: drive circuit

105a:二極體 105a: Diode

105b:電感 105b: Inductance

105c:驅動器 105c: drive

106:LED模組 106: LED module

110:開關面板 110: switch panel

110a:開關 110a: switch

110b:LED 110b: LED

Claims (10)

一種LED驅動電路，係用以和一開關面板搭配以驅動一LED模組，該開關面板包含一開關及和該開關並聯之一LED指示燈，當該開關閉合時，該LED驅動電路依一輸入電壓產生一輸出電流以驅動該LED模組，當該開關斷開時，該LED驅動電路提供一電流路徑以點亮該LED指示燈，該LED驅動電路的特徵在於具有：一第一分壓電路，用以依該輸入電壓提供一第一感測電壓；以及一檢測電路，具有一感測單元及一可禁能之電流源，該感測單元係用以檢測該第一感測電壓低於一第一參考電壓的時間是否超過一閾值以決定一致能信號的狀態，若是，則使該致能信號呈現一作用狀態以致能該可禁能之電流源，若否，則使該致能信號呈現一不作用狀態以禁能該可禁能之電流源，且該可禁能之電流源在被致能時能夠適應性地調整其吸入電流的電流值以使該吸入電流和通過該LED指示燈之一預定電流相等。 An LED driving circuit is used with a switch panel to drive an LED module. The switch panel includes a switch and an LED indicator light connected in parallel with the switch. When the switch is closed, the LED driving circuit depends on an input The voltage generates an output current to drive the LED module. When the switch is turned off, the LED drive circuit provides a current path to light up the LED indicator. The LED drive circuit is characterized by: a first voltage divider Circuit for providing a first sensing voltage according to the input voltage; and a detection circuit having a sensing unit and a disableable current source, the sensing unit is used for detecting that the first sensing voltage is low Whether the time at a first reference voltage exceeds a threshold to determine the state of the enable signal, if yes, make the enable signal present an active state to enable the current source that can be disabled, if not, enable the enable signal The signal presents an inactive state to disable the disableable current source, and when the disableable current source is enabled, the current value of its sink current can be adjusted adaptively so that the sink current passes through the LED One of the indicator lights has the same predetermined current. 如申請專利範圍第1項所述之LED驅動電路，其中，該第一分壓電路係一串聯電阻電路。 According to the LED driving circuit described in item 1 of the scope of patent application, the first voltage divider circuit is a series resistor circuit. 如申請專利範圍第1項所述之LED驅動電路，其中，該感測單元具有：一比較器，用以對該第一感測電壓和該第一參考電壓進行一電壓比較運算以產生一比較結果信號，當該第一感測電壓大於該第一參考電壓時，該比較結果信號呈現一低電位，當該第一感測電壓小於該第一參考電壓時，該比較結果信號呈現一高電位；一計時電路，用以在該比較結果信號呈現所述高電位的時間超過該閾值時使一計時輸出信號呈現所述高電位；以及一反及閘，用以對該比較結果信號及該計時輸出信號進行一反及邏輯運算以產生所述的致能信號。 According to the LED driving circuit described in claim 1, wherein the sensing unit has: a comparator for performing a voltage comparison operation on the first sensing voltage and the first reference voltage to generate a comparison A result signal. When the first sensing voltage is greater than the first reference voltage, the comparison result signal presents a low level, and when the first sensing voltage is less than the first reference voltage, the comparison result signal presents a high level ; A timing circuit for making a timing output signal present the high potential when the time for the comparison result signal to present the high potential exceeds the threshold; and a flip and gate for the comparison result signal and the timing The output signal performs an inverse and logical operation to generate the enable signal. 如申請專利範圍第1項所述之LED驅動電路，其中，該可禁能之電流源具有：一JFET電晶體，具有一閘極、一汲極和一源極，該閘極耦接一參考地，該汲極耦接該輸入電壓；一第二分壓電路，用以依該JFET電晶體的所述源極的電壓產生一第二感測電壓；一放大器，具有一致能控制端、一正輸入端、一負輸入端及一輸出端，該致能控制端耦接所述的致能信號，該正輸入端耦接該第二感測電壓，該負輸入端耦接一第二參考電壓；以及一NMOS電晶體，具有一閘極以耦接該放大器之所述輸出端，一汲極以耦接該JFET電晶體之所述源極，及一源極以耦接該參考地。 The LED driving circuit described in the first item of the scope of patent application, wherein the disableable current source has: a JFET transistor with a gate, a drain and a source, and the gate is coupled to a reference Ground, the drain is coupled to the input voltage; a second voltage divider circuit for generating a second sensing voltage according to the voltage of the source of the JFET transistor; an amplifier having a uniform energy control terminal, A positive input terminal, a negative input terminal and an output terminal, the enable control terminal is coupled to the enable signal, the positive input terminal is coupled to the second sensing voltage, the negative input terminal is coupled to a second Reference voltage; and an NMOS transistor having a gate to couple to the output terminal of the amplifier, a drain to couple to the source of the JFET transistor, and a source to couple to the reference ground . 如申請專利範圍第1項所述之LED驅動電路，其中，該輸入電壓係一交流電壓經一全波整流單元整流後所產生的電壓。 The LED driving circuit described in the first item of the scope of patent application, wherein the input voltage is a voltage generated by an AC voltage rectified by a full-wave rectifier unit. 一種LED燈具，包括一LED驅動電路及一LED模組，其中，該LED驅動電路係用以和一開關面板搭配以驅動該LED模組，該開關面板包含一開關及和該開關並聯之一LED指示燈，當該開關閉合時，該LED驅動電路依一輸入電壓產生一輸出電流以驅動該LED模組，當該開關斷開時，該LED驅動電路提供一電流路徑以點亮該LED指示燈，該LED驅動電路的特徵在於具有：一第一分壓電路，用以依該輸入電壓提供一第一感測電壓；以及一檢測電路，具有一感測單元及一可禁能之電流源，該感測單元係用以檢測該第一感測電壓低於一第一參考電壓的時間是否超過一閾值以決定一致能信號的狀態，若是，則使該致能信號呈現一作用狀態以致能該可禁能之電流源，若否，則使該致能信號呈現一不作用狀態以禁能該可禁能之電流源，且該可禁能之電流源在被致能時能夠適應性地調整其吸入電流的電流值以使該吸入電流和通過該LED指示燈之一預定電流相等。 An LED lamp includes an LED drive circuit and an LED module, wherein the LED drive circuit is used with a switch panel to drive the LED module. The switch panel includes a switch and an LED in parallel with the switch Indicator light. When the switch is closed, the LED drive circuit generates an output current according to an input voltage to drive the LED module. When the switch is open, the LED drive circuit provides a current path to light up the LED indicator. , The LED driving circuit is characterized by having: a first voltage divider circuit for providing a first sensing voltage according to the input voltage; and a detection circuit having a sensing unit and a disable current source The sensing unit is used to detect whether the time when the first sensing voltage is lower than a first reference voltage exceeds a threshold to determine the state of the enabling signal, and if so, to make the enabling signal present an active state to enable The disableable current source, if not, makes the enable signal present a non-active state to disable the disableable current source, and the disableable current source can be adaptively enabled when it is enabled The current value of the suction current is adjusted to make the suction current equal to a predetermined current through the LED indicator. 如申請專利範圍第6項所述之LED燈具，其中，該第一分壓電路係一串聯電阻電路。 According to the LED lamp described in item 6 of the scope of patent application, the first voltage divider circuit is a series resistor circuit. 如申請專利範圍第6項所述之LED燈具，其中，該感測單元具有：一比較器，用以對該第一感測電壓和該第一參考電壓進行一電壓比較運算以產生一比較結果信號，當該第一感測電壓大於該第一參考電壓時，該比較結果信號呈現一低電位，當該第一感測電壓小於該第一參考電壓時，該比較結果信號呈現一高電位；一計時電路，用以在該比較結果信號呈現所述高電位的時間超過該閾值時使一計時輸出信號呈現所述高電位；以及一反及閘，用以對該比較結果信號及該計時輸出信號進行一反及邏輯運算以產生所述的致能信號。 The LED lamp as described in item 6 of the scope of patent application, wherein the sensing unit has: a comparator for performing a voltage comparison operation on the first sensing voltage and the first reference voltage to generate a comparison result Signal, when the first sensing voltage is greater than the first reference voltage, the comparison result signal presents a low potential, and when the first sensing voltage is less than the first reference voltage, the comparison result signal presents a high potential; A timing circuit for making a timing output signal exhibit the high potential when the time for the comparison result signal to exhibit the high potential exceeds the threshold; and a flip-flop for the comparison result signal and the timing output The signal undergoes an inverse and logical operation to generate the enabling signal. 如申請專利範圍第6項所述之LED燈具，其中，該可禁能之電流源具有：一JFET電晶體，具有一閘極、一汲極和一源極，該閘極耦接一參考地，該汲極耦接該輸入電壓；一第二分壓電路，用以依該JFET電晶體的所述源極的電壓產生一第二感測電壓；一放大器，具有一致能控制端、一正輸入端、一負輸入端及一輸出端，該致能控制端耦接所述的致能信號，該正輸入端耦接該第二感測電壓，該負輸入端耦接一第二參考電壓；以及一NMOS電晶體，具有一閘極以耦接該放大器之所述輸出端，一汲極以耦接該JFET電晶體之所述源極，及一源極以耦接該參考地。 The LED lamp described in item 6 of the scope of patent application, wherein the disableable current source has: a JFET transistor with a gate, a drain and a source, and the gate is coupled to a reference ground , The drain is coupled to the input voltage; a second voltage divider circuit for generating a second sensing voltage according to the voltage of the source of the JFET transistor; an amplifier with a consistent energy control terminal, a A positive input terminal, a negative input terminal, and an output terminal, the enable control terminal is coupled to the enable signal, the positive input terminal is coupled to the second sensing voltage, and the negative input terminal is coupled to a second reference Voltage; and an NMOS transistor having a gate to couple to the output terminal of the amplifier, a drain to couple to the source of the JFET transistor, and a source to couple to the reference ground. 如申請專利範圍第6項所述之LED燈具，其中，該輸入電壓係一交流電壓經一全波整流單元整流後所產生的電壓。 For the LED lamp described in item 6 of the scope of patent application, the input voltage is a voltage generated by an AC voltage rectified by a full-wave rectifier unit.
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TW454941U (en) * 2000-01-14 2001-09-11 World Search Co Ltd Switch box with night lamp and power failure alarm
US20120155069A1 (en) * 2010-12-16 2012-06-21 Chen Yarn Chen Multi-purpose illumination device
CN202873125U (en) * 2012-08-24 2013-04-10 林梅冬 Driver integrating light modulation of touch switch with LED illumination
CN103270609A (en) * 2010-12-27 2013-08-28 松下电器产业株式会社 Light-emitting diode drive circuit and led light source

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TW454941U (en) * 2000-01-14 2001-09-11 World Search Co Ltd Switch box with night lamp and power failure alarm
US20120155069A1 (en) * 2010-12-16 2012-06-21 Chen Yarn Chen Multi-purpose illumination device
CN103270609A (en) * 2010-12-27 2013-08-28 松下电器产业株式会社 Light-emitting diode drive circuit and led light source
CN202873125U (en) * 2012-08-24 2013-04-10 林梅冬 Driver integrating light modulation of touch switch with LED illumination

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