KR20000040964A - Piezo-electric element driving circuit with input line regulation capability - Google Patents
Piezo-electric element driving circuit with input line regulation capability Download PDFInfo
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- KR20000040964A KR20000040964A KR1019980056719A KR19980056719A KR20000040964A KR 20000040964 A KR20000040964 A KR 20000040964A KR 1019980056719 A KR1019980056719 A KR 1019980056719A KR 19980056719 A KR19980056719 A KR 19980056719A KR 20000040964 A KR20000040964 A KR 20000040964A
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- piezoelectric element
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- 238000000034 method Methods 0.000 claims description 15
- 238000001514 detection method Methods 0.000 claims description 2
- 238000004364 calculation method Methods 0.000 claims 2
- 239000000919 ceramic Substances 0.000 abstract description 3
- 238000010586 diagram Methods 0.000 description 7
- 239000004973 liquid crystal related substance Substances 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
Classifications
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N30/00—Piezoelectric or electrostrictive devices
- H10N30/80—Constructional details
- H10N30/802—Drive or control circuitry or methods for piezoelectric or electrostrictive devices not otherwise provided for
- H10N30/804—Drive or control circuitry or methods for piezoelectric or electrostrictive devices not otherwise provided for for piezoelectric transformers
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
- H05B41/14—Circuit arrangements
- H05B41/36—Controlling
- H05B41/38—Controlling the intensity of light
- H05B41/39—Controlling the intensity of light continuously
- H05B41/392—Controlling the intensity of light continuously using semiconductor devices, e.g. thyristor
- H05B41/3921—Controlling the intensity of light continuously using semiconductor devices, e.g. thyristor with possibility of light intensity variations
- H05B41/3927—Controlling the intensity of light continuously using semiconductor devices, e.g. thyristor with possibility of light intensity variations by pulse width modulation
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
- H05B41/14—Circuit arrangements
- H05B41/26—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc
- H05B41/28—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters
- H05B41/282—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters with semiconductor devices
- H05B41/2825—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters with semiconductor devices by means of a bridge converter in the final stage
- H05B41/2827—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters with semiconductor devices by means of a bridge converter in the final stage using specially adapted components in the load circuit, e.g. feed-back transformers, piezoelectric transformers; using specially adapted load circuit configurations
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
- H05B41/14—Circuit arrangements
- H05B41/26—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc
- H05B41/28—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters
- H05B41/282—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters with semiconductor devices
- H05B41/2825—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters with semiconductor devices by means of a bridge converter in the final stage
- H05B41/2828—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters with semiconductor devices by means of a bridge converter in the final stage using control circuits for the switching elements
Abstract
Description
본 발명은 압전소자 구동회로 및 그 제어방법에 관한 것으로서, 특히 DC-DC컨버터를 사용하지 않는 압전소자 구동회로 및 그 제어방법에 관한 것이다.BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric element driving circuit and a control method thereof, and more particularly, to a piezoelectric element driving circuit and a control method thereof without using a DC-DC converter.
최근 들어 액정디스플레이(LCD)를 채용한 노트북 컴퓨터의 소형화 및 박형화의 기술이 급속도로 발전됨에 따라 이 액정 디스플레이 장치에 필수적으로 사용되어지는 백라이트(Back light)인버터의 소형화 및 고효율화가 매우 필요하게 되었다.Recently, as the technology of miniaturization and thinning of a notebook computer employing a liquid crystal display (LCD) has been rapidly developed, the miniaturization and high efficiency of a backlight light inverter, which is essential for the liquid crystal display device, has become very necessary.
그러나, 종래의 백라이트용 DC-AC인버터에 사용되어 지는 마그네틱 트랜스(Magnetic transformer)는 소형화 및 고효율화의 한계점을 가지고 있다.However, magnetic transformers used in conventional DC-AC inverters for backlights have limitations of miniaturization and high efficiency.
이를 개선하기 위해 수년전부터 PCT(PIEZO-CERAMIC TRANSFORMER)를 이용한 인버터가 연구되고 있으나 일반적으로 구동회로가 복잡한 문제와 입력전압의 가변범위가 넓은 응용회로에서 PCT구동회로에 가해지는 전압을 일정하게 유지해 주기 위한 또 하나의 DC-DC 컨버터가 필요한 문제점을 안고 있었다.In order to improve this problem, inverters using PCT (PIEZO-CERAMIC TRANSFORMER) have been studied for many years, but in general, the drive circuit keeps the voltage applied to the PCT drive circuit constant in complex circuits and application circuits with a wide range of input voltages. Another problem was the need for another DC-DC converter.
즉, 지금까지 실용화되고 있는 PCT인버터의 일반적인 형태로는That is, the general form of the PCT inverter that has been put to practical use so far
1. 벅 또는 부스트(BUCK or BOOST) DC-DC컨버터 + 푸시풀 인버터1. BUCK or BOOST DC-DC Converter + Push-Pull Inverter
2. DC-DC컨버터 + 싱글엔드(SINGLE-ENDED) 준공진형 인버터2. DC-DC converter + single-ended semi-resonant inverter
3. DC-DC컨버터 + 하프브리지 인버터3. DC-DC Converter + Half Bridge Inverter
4. DC-DC컨버터 + 플라이백 싱글 엔드 준 공진형 인버터4. DC-DC Converter + Flyback Single End Quasi-Resonant Inverter
등과 같은 것이 있으나 모두 2단 인버터로 동작되고 있어 각 단마다 별도의 스위칭소자와 제어회로를 사용해야 하므로 회로가 매우 복잡해진다.There are the same, but all of them are operated by a two-stage inverter, which requires a separate switching device and control circuit for each stage, which makes the circuit very complicated.
도 6은 하프브리지 인버터를 채용한 종래의 압전소자 구동회로이다.6 is a conventional piezoelectric element driving circuit employing a half-bridge inverter.
도 6에 도시한 바와 같이, 입력전압이 Vmax에서 Vmin까지 변할 때 A점에서 일정한 전압을 만들어 PCT구동용 스위칭소자인 트랜지스터 Q1, Q2에 공급을 하고 제어회로(2)에서는 트랜지스터Q1, Q2의 ON/OFF시간의 비율을 항상 일정하게 제어하여 PCT입력단자인 B점을 일정한 전압으로 구동하여 램프를 동작시키고 있다.As shown in Fig. 6, when the input voltage changes from V max to V min , a constant voltage is made at point A, and is supplied to transistors Q 1 and Q 2 , which are PCT driving switching elements, and in the control circuit 2, transistor Q The ratio of ON and OFF times of 1 and Q 2 is always controlled constantly, and the lamp is operated by driving point B, which is a PCT input terminal, with a constant voltage.
이러한 회로의 복잡성을 피하기 위해 반도체회사에서는 여러 제어회로를 하나의 칩속에 집적화하여 1단의 DC-AC 인버터 개념으로 사용하고 있으나 이것 역시 여러 스위칭소자를 사용해야 하는 단점을 갖고 있다.In order to avoid the complexity of the circuit, the semiconductor company integrates several control circuits in one chip and uses it as a single-stage DC-AC inverter concept, but this also has the disadvantage of using several switching elements.
본 발명의 목적은 상술한 종래기술의 문제점을 해소하기 위해 이루어진 것으로서, 스위칭소자의 개수를 줄이고 DC-DC컨버터를 사용하지 않는 압전소자 구동회로 및 그 제어방법을 제공하는 것이다.An object of the present invention is to solve the problems of the prior art described above, to reduce the number of switching elements and to provide a piezoelectric element driving circuit and a control method thereof without using a DC-DC converter.
본 발명의 다른 목적은 입력전압이 넓게 변화해도 PCT구동회로가 필요로 하는 일정한 전압을 얻을 수 있는 압전소자 구동회로 및 그 제어방법을 제공하는 것이다.Another object of the present invention is to provide a piezoelectric element driving circuit and a method of controlling the same, which can obtain a constant voltage required by a PCT driving circuit even if the input voltage varies widely.
본 발명의 또 다른 목적은 인버터의 부수적기능으로 출력전류를 가변시켜 액정 디스플레이 백라이트의 밝기를 가변시키는 새로운 제광(DIMMING)개념과 PCT가 주변의 온도 및 충격에 의해 순간적으로 공진주파수와 회로의 동작주파수가 왜곡되어 자동적으로 공진주파수를 추적하는 압전소자 구동회로 및 그 제어방법을 제공하는 것이다.Another object of the present invention is a new concept of dimming that changes the output current as a secondary function of the inverter to change the brightness of the liquid crystal display backlight, and the PCT instantaneously reacts with the resonance frequency and the operating frequency of the circuit. It is to provide a piezoelectric element driving circuit and a control method for tracking the resonance frequency automatically distorted.
도 1은 본 발명에 따른 압전소자 구동회로의 블럭도,1 is a block diagram of a piezoelectric element driving circuit according to the present invention;
도 2는 본 발명에 따른 PCT구동부의 회로도,2 is a circuit diagram of a PCT driver according to the present invention;
도 3은 도 2에 도시된 입력전압에 따른 B점의 파형도,3 is a waveform diagram of point B according to the input voltage shown in FIG.
도 4는 도 3에 도시된 파형을 푸리에급수로 전개하기 위한 개념도,4 is a conceptual diagram for developing a waveform shown in FIG. 3 into a Fourier series;
도 5는 PCT이 주파수에 대한 입출력승압비의 특성곡선을 도시한 도면,5 is a diagram showing a characteristic curve of an input / output boost ratio for a PCT frequency;
도 6은 종래의 압전소자 구동회로도.6 is a conventional piezoelectric element driving circuit diagram.
※ 도면의 주요부분에 따른 부호의 설명 ※※ Explanation of symbols according to main part of drawing ※
1…배전압정류기, 2…가산증폭기, 3…듀티비제어기 ,One… Double voltage rectifier; Addition amplifier, 3... Duty ratio controller
4…위상검파기, 5…VCO, 6…톱니파발생기,4… Phase detector, 5... VCO, 6... Sawtooth Generator,
7…PWM변조기, 8…PCT구동부.7... PWM modulator, 8... PCT drive section.
상기 목적을 달성하기 위해 본 발명의 압전소자 구동회로는 입력전압의 변동에 따른 최대출력전류를 생성하기 위한 압전소자 구동회로로서, 램프,상기 램프를 기동하는 압전소자,상기 압전소자를 구동하는 PCT구동수단, 출력전압을 정류하는 배전압정류기, 디밍전압과 출력전류를 가산하여 오차신호를 출력하는 증폭수단,상기 배전압정류기의 입력신호와 상기 PCT구동수단의 입력신호의 위상을 비교하는 위상검파수단 및 상기 위상검파수단에서의 출력신호와 상기 증폭수단에서의 출력신호에 따라 상기 PCT구동수단에 공급되는 신호의 듀티비를 제어하여 입력전압이 Vmin에서 Vmax까지 변화하더라도 기본주파수 성분의 진폭을 항상 일정하게 얻을 수 있는 변조수단을 구비하는 것으로 하였다.In order to achieve the above object, the piezoelectric element driving circuit of the present invention is a piezoelectric element driving circuit for generating a maximum output current according to a change in an input voltage, and includes a lamp, a piezoelectric element for starting the lamp, and a PCT for driving the piezoelectric element. A driving means, a double voltage rectifier for rectifying the output voltage, an amplifying means for outputting an error signal by adding a dimming voltage and an output current, and a phase detection for comparing a phase of an input signal of the double voltage rectifier and an input signal of the PCT driving means. By controlling the duty ratio of the signal supplied to the PCT driving means according to the output signal from the means and the phase detecting means and the output signal from the amplifying means, the amplitude of the fundamental frequency component is always maintained even if the input voltage changes from Vmin to Vmax. It is supposed to have a modulation means which can be obtained constantly.
압전소자 구동회로의 디밍제어방법으로서, 임의의 입력전압 Vx에서 최대출력전류 Iomax를 생성하는 Dx (여기서, Dx는 임의의 전압 Vx에서 한주기에 대한 스위치 도통시간의 비를 의미한다)를 결정하고,As a dimming control method of a piezoelectric element driving circuit, a Dx for generating a maximum output current Iomax at an arbitrary input voltage Vx (where Dx is a ratio of switch conduction time for one cycle at an arbitrary voltage Vx) is determined.
상기 디밍을 위해 상기 Dx의 값을 좁혀서 원하는 밝기 만큼의 전류를 흐르게한다.For dimming, the value of the Dx is narrowed to allow current to flow as desired.
이하, 본 발명의 실시예를 도면에 따라 구체적으로 설명한다. 또한, 본원의 도면에 있어서 동일부호는 동일부분을 나타내며 그 반복적인 설명은 생략한다.Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, in the drawing of this application, the same code | symbol shows the same part, and the repeated description is abbreviate | omitted.
도 1은 본 발명에 따른 압전소자 구동회로의 블럭도이다.1 is a block diagram of a piezoelectric element driving circuit according to the present invention.
도 1에 있어서, (1)은 출력전압을 정류하는 배전압정류기, (2)는 디밍전압과 출력전류를 가산하여 출력신호를 생성하는 가산증폭기, (3)은 가산증폭기(2)에서 출력된 신호에 의해 듀티비를 제어하는 듀티비제어기, (4)는 후에 기술하는 PCT구동부(8)과 배전압정류기(1)의 출력신호의 상대적위상을 검출하는 위상검파기이다.In Fig. 1, reference numeral 1 denotes a double voltage rectifier for rectifying the output voltage, 2 an adder amplifier that adds a dimming voltage and an output current to generate an output signal, and 3 denotes an output amplifier that is output from the adder amplifier 2. A duty ratio controller (4) for controlling the duty ratio by a signal is a phase detector for detecting the relative phase of the output signal of the PCT driver 8 and the double voltage rectifier 1 described later.
(5)는 전압제어발진기(VCO : Voltage Controlled Oscillator)로서, 위상검파기(4)의 출력신호에서 제어전압으로 발진주파수를 변화시킨다. (6)은 VCO(5)에서 출력된 전압 또는 전류를 시간에 비례하는 톱니파를 형성하는 톱니파발생기이고, (7)은 PWM(Pulse Width Modulation)변조기로서, 듀티비제어기(3)의 출력과 톱니파발생기의 출력에 따라 주기적인 펄스폭으로 변화시켜 출력한다. (8)은 PCT구동부로서, 구체적인 설명은 도 2에 따라 후술한다.(5) is a voltage controlled oscillator (VCO), which changes the oscillation frequency from the output signal of the phase detector 4 to the control voltage. (6) is a sawtooth wave generator for forming a sawtooth wave proportional to the voltage or current output from the VCO (5), (7) is a pulse width modulation (PWM) modulator, the output and the sawtooth wave of the duty ratio controller (3) It changes the pulse width periodically and outputs it according to the generator output. Denoted at 8 is a PCT driver, which will be described later with reference to FIG. 2.
(9)는 압전세라믹트랜스(PCT : PIEZO-CERAMIC TRANSFORMER)이고, (10)은 램프이다.(9) is a piezoceramic transformer (PCT: PIEZO-CERAMIC TRANSFORMER), and (10) is a lamp.
다음에, 도 2에 따라 PCT구동부(8)에 대해 구체적으로 기술한다.Next, the PCT drive unit 8 will be described in detail with reference to FIG. 2.
PCT구동부(8)은 인버터, 2개의 트랜지스터 Q1, Q2및 LC필터로 이루어진다.The PCT driver 8 consists of an inverter, two transistors Q 1 , Q 2 and an LC filter.
도 2의 기본구조는 도 6에 도시된 종래의 기술과 유사하지만, 트랜지스터 Q1, Q2의 온, 오프 제어방법이 전혀 상이하다. 또, 도 6의 구조에 있어서는 구동트랜스를 사용해야 하지만, 도 2의 구조에서는 구동트랜스를 사용하지 않는다.The basic structure of FIG. 2 is similar to the conventional technique shown in FIG. 6, but the on and off control methods of the transistors Q 1 and Q 2 are completely different. In addition, although the drive transformer must be used in the structure of FIG. 6, the drive transformer is not used in the structure of FIG.
또한, 도 6의 구조에서는 A점에서 입력전압을 조절하여 항상 일정한 전압을 공급해야 한다. 그러나, 본 발명에 따른 구성에 있어서는 A점에 변화하는 입력전압이 그대로 공급되어도 B점에서 항상 일정한 전압이 출력되도록 제어회로가 구성되는 것이다.In addition, in the structure of FIG. 6, a constant voltage must always be supplied by adjusting an input voltage at point A. FIG. However, in the configuration according to the present invention, the control circuit is configured so that a constant voltage is always output at the point B even if the input voltage which changes at the point A is supplied as it is.
즉, 도 2에 있어서 트랜지스터 Q1, Q2가 온, 오프하는 동작상태는 매 한 주기마다 트랜지스터 Q1이 온하면 나머지 주기는 반드시 트랜지스터 Q2가 온되는, 즉 입력전압의 변화에 대해 온, 오프 시간이 서로 다르게 조정되도록 해야 한다.That is, in FIG. 2, the operation state in which the transistors Q 1 and Q 2 are turned on and off is that if the transistor Q 1 is turned on every cycle, the rest of the cycles always turn on the transistor Q 2 . Ensure that the off time is adjusted differently.
B점에서 파형은 도 4에 도시한 바와 같다.The waveform at point B is as shown in FIG.
즉, 입력전압이 높을 때에는 트랜지스터 Q1의 온시간이 짧고,입력전압이 낮을 때에는 반대로 트랜지스터 Q1의 온시간을 길게 제어하여 아래와 같은 이론을 추출할 수 있다. 도 3의 파형을 도 4를 참조하여 푸리에급수로 전개하면 다음과 같다.That is, when the input voltage is high, the on time of the transistor Q 1 is short, and when the input voltage is low, the on time of the transistor Q 1 is controlled on the contrary, and the following theory can be extracted. The waveform of FIG. 3 is expanded to Fourier series with reference to FIG. 4 as follows.
bK= 0 [ ∵f(t)는 우함수(EVEN FUNCTION)]b K = 0 [∵f (t) is EVEN FUNCTION]
식 1에서In equation 1
이 때, A는 Vmin전압에서 Vmax전압까지 변화를 한다. 만일, Vmin전압에서 트랜지스터Q1의 온시간, 펄스폭과 펄스주기와의 비인 듀티비D를 D1(D1, max≤50%)가 되게 조절을 하고, 입력전압이 Vmax전압까지 변화할 때 이 D값에 해당하는 전압파형을 푸리에급수전개를 하였을 때 기본파성분의 크기가 같아지도록 D값을 제어하면, 입력전압V에 관계없이 항상 같은 기본파 주파수 성분, 즉 a11=a12를 얻을 수 있게 된다.At this time, A changes from V min voltage to V max voltage. If the duty ratio D, which is the ratio of the ON time, the pulse width and the pulse period of the transistor Q 1 at the V min voltage, is adjusted to be D 1 (D 1, max ≤ 50%), the input voltage changes to the V max voltage. When the value D is controlled so that the magnitude of the fundamental wave component is the same when Fourier series of voltage waveforms corresponding to the value D are applied, the same fundamental wave frequency component is always used regardless of the input voltage V, that is, a 11 = a 12 Will be obtained.
즉, 입력전압이 Vmin과 Vmax범위내로 변할 때 항상 일정한 진폭의 기본파 주파수 성분을 얻을 수 있어 입력조정(Input line-regulaiton)이 가능하게 된다. 이를 수식으로 전개하면 아래와 같다.That is, when the input voltage is changed within the range of V min and V max, the fundamental wave frequency component of constant amplitude can be obtained at all times, thereby enabling input line-regulaiton. If you expand this into a formula,
일반적으로
여기서, a11=a1x가 되도록 Dx를 구하면,Here, if Dx is found such that a 11 = a 1x ,
상기 식 3은 임의의 입력전압 VX에서 Vmin과 D1로 얻어지는 기본주파수 성분의 진폭과 같은 진폭을 얻을 수 있는 듀티비를 계산하는 일반해다.Equation 3 is a general formula for calculating the duty ratio to obtain an amplitude equal to the amplitude of the fundamental frequency component obtained by V min and D 1 at any input voltage V X.
하기의 표 1은 입력전압에 대한 펄스폭의 비로서, 상술한 일반해로 구한 몇가지의 해를 나타낸 것이다.Table 1 below shows several solutions obtained from the general solution described above as a ratio of pulse width to input voltage.
(Dx : 임의의 전압Vx에서 한주기T에 대한 스위치 도통시간DT의 비)(Dx: ratio of switch conduction time DT for one cycle T at arbitrary voltage Vx)
즉, 도 2에서 B점파형을 8V, 50%, 10V, 29. 5%, … 20V, 13%가 되도록 PWM변조기(7)에서 도통시간 비를 제어하고 PCT구동부(8)내의 LC필터로 기본주파수 성분만 통과시키면, C점에는 항상 a1=3. 6Vrms가 되는 정현파를 얻을 수 있다.That is, in FIG. 2, the B point waveform is 8V, 50%, 10V, 29. 5%,... Controlling the conduction time ratio in the PWM modulator 7 so as to be 20V, 13%, and passing only the fundamental frequency component through the LC filter in the PCT driver 8, always a 1 = 3. A sinusoidal wave of 6V rms can be obtained.
본 발명에 따르면, 이 정현파 전압으로 램프(10)의 부하에 원하는 전류Iomax를 흐르게 하는 PCT구동부(8)을 설계하여 초단의 DC-DC컨버터를 사용하지 않고도 넓은 범위의 입력전압을 조정할 수 있는 DC-AC인버터를 설계할 수 있다.According to the present invention, by designing the PCT drive unit 8 to flow the desired current I omax to the load of the lamp 10 by this sinusoidal voltage, it is possible to adjust a wide range of input voltage without using a DC-DC converter of the first stage DC-AC inverters can be designed.
다음에, 본 발명에 따른 디밍(dimming)방법을 설명하면 다음과 같다.Next, a dimming method according to the present invention will be described.
상술한 바와 같이, 본 발명의 구동회로는 입력전압의 변동에 따른 최대출력전류Iomax를 내기 위해 듀티비를 조정하게 한다. 임의의 전압Vx에서 최대출력전류Iomax를 낼 수 있는 Dx가 결정되면, 본 발명에서는 디밍을 위해 다시 이 Dx값을 좁혀서 원하는 밝기만큼의 전류를 흐르게 하는 것이다.As described above, the driving circuit of the present invention allows the duty ratio to be adjusted to obtain the maximum output current I omax in accordance with the variation of the input voltage. When D x , which can produce the maximum output current I omax at an arbitrary voltage V x , is determined, the present invention narrows the value of D x again for dimming so that a current of the desired brightness flows.
즉, 도 1에 있어서, 듀티비제어기(3)의 출력신호가 PWM변조기(7)에서 DX를 좁혀주는 방향으로 배전압정류기(1)과 가산증폭기(2)를 설계한다.That is, the design of the output signal PWM modulator 7 times voltage rectifier (1) and the summing amplifier (2) in the direction to narrow the D X in the method, a duty ratio controller 3 in FIG.
다음에, PCT의 최적주파수를 찾는 방법에 대해 도 5을 참조해서 설명한다.Next, a method of finding the optimum frequency of the PCT will be described with reference to FIG.
도 5에 있어서, fo는 PCT공진주파수이고, fr은 동작주파수이다.In Fig. 5, fo is the PCT resonance frequency and fr is the operating frequency.
일반적으로, PCT의 최대승압비는 회로의 동작주파수(fr)가 PCT의 공진주파수(fo)와 일치할 때 얻어진다. 그러나, fo=fr이 되게 회로를 동작시키면 VCO와 PCT의 온도특성 및 외부환경 등이 요인에 의해 VCO의 동작주파수가 fo보다 조금 낮은 주파수에서 동작할 수도 있다.In general, the maximum boost ratio of the PCT is obtained when the operating frequency fr of the circuit coincides with the resonance frequency fo of the PCT. However, if the circuit is operated so that fo = fr, the operating frequency of the VCO may operate at a slightly lower frequency than fo due to factors such as temperature characteristics and external environment of the VCO and PCT.
이 경우에는 PCT자체의 효율이 떨어지게 되므로 본 발명의 인버터는 동작주파수가 PCT공진주파수보다 항상 조금 높은 주파수에서 동작하도록 하였다.In this case, since the efficiency of the PCT itself is lowered, the inverter of the present invention always operates at a slightly higher frequency than the PCT resonance frequency.
이를 위해 본 발명에서는 도 1에 도시한 바와 같이, PCT 입력전압 파형과 출력파형의 위상을 비교하는 위상검파기(4)를 마련하여 온도나 외부환경에 의해 PCT공진주파수가 어긋나도 항상fr>fo가 되는 회로동작주파수로 동작하게 처리한다.To this end, in the present invention, as shown in FIG. 1, a phase detector 4 for comparing the phase of the PCT input voltage waveform and the output waveform is provided so that even if the PCT resonant frequency is shifted due to temperature or external environment, fr > Process at the operating frequency of the circuit.
상술한 바와 같이, 본 발명의 압전소자 구동회로에 의하면, 온도나 외부환경에 영향을 받지 않고 스위칭소자의 부품개수를 감소시켜 인버터를 소형화시킬 수 있다.As described above, according to the piezoelectric element driving circuit of the present invention, the inverter can be miniaturized by reducing the number of parts of the switching element without being affected by temperature or external environment.
이상, 본 발명을 상기 실시예에 따라서 구체적으로 설명했지만, 본 발명은 상기 실시예에 한정되는 것은 아니고 그 요지를 이탈하지 않는 범위내에서 여러가지로 변경가능한 것은 물론이다.As mentioned above, although this invention was demonstrated concretely according to the said Example, this invention is not limited to the said Example and can be variously changed in the range which does not deviate from the summary.
Claims (5)
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1019980056719A KR100325263B1 (en) | 1998-12-21 | 1998-12-21 | Piezoelectric element drive circuit with adjustable input and its control method |
| TW088103929A TW428360B (en) | 1998-12-21 | 1999-03-15 | Driving circuit of a piezo-eramic transformer capable of controlling an input voltage and a dimming control method thereof |
| DE19918607A DE19918607A1 (en) | 1998-12-21 | 1999-04-23 | Drive circuit for piezoelectric converter for controlling input voltage for notebook LCD back lighting arrangement, holds base component amplitude constant if input voltage changes from minimum to a maximum value |
| JP11219793A JP2000188880A (en) | 1998-12-21 | 1999-08-03 | Piezoelectric element driving circuit and method for controlling the same |
| US09/557,901 US6331748B1 (en) | 1998-12-21 | 2000-04-21 | Driving circuit of a piezo-ceramic transformer capable of controlling an input voltage and a dimming control method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1019980056719A KR100325263B1 (en) | 1998-12-21 | 1998-12-21 | Piezoelectric element drive circuit with adjustable input and its control method |
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| Publication Number | Publication Date |
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| KR20000040964A true KR20000040964A (en) | 2000-07-15 |
| KR100325263B1 KR100325263B1 (en) | 2002-06-26 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR1019980056719A KR100325263B1 (en) | 1998-12-21 | 1998-12-21 | Piezoelectric element drive circuit with adjustable input and its control method |
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| Country | Link |
|---|---|
| JP (1) | JP2000188880A (en) |
| KR (1) | KR100325263B1 (en) |
| DE (1) | DE19918607A1 (en) |
| TW (1) | TW428360B (en) |
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|---|---|---|---|---|
| KR20200036044A (en) * | 2015-07-29 | 2020-04-06 | 티디케이 일렉트로닉스 아게 | Frequency control method of piezoelectric transformer and switch arrangement structure including piezoelectric transformer |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007043866A (en) * | 2005-08-05 | 2007-02-15 | Tamura Seisakusho Co Ltd | Inverter circuit |
| KR100665328B1 (en) | 2005-12-15 | 2007-01-09 | 삼성전기주식회사 | An apparatus for driving of piezoelectric ultrasonic motor |
| DE102006021559A1 (en) * | 2006-05-08 | 2008-11-13 | Universität Paderborn | Food arrangement for an ultrasonic device |
| CN106134105B (en) * | 2014-03-20 | 2020-02-04 | 艾里尔大学研究与开发有限公司 | Method and system for controlling signal phase and application equipment thereof |
| CN106253741B (en) * | 2015-12-29 | 2018-06-12 | 中国科学院长春光学精密机械与物理研究所 | Piezoelectric Ceramic device |
| CN112170105B (en) * | 2020-09-18 | 2022-06-10 | 深圳市轴心压电技术有限公司 | Novel piezoelectric ceramic valve drive control system |
-
1998
- 1998-12-21 KR KR1019980056719A patent/KR100325263B1/en not_active IP Right Cessation
-
1999
- 1999-03-15 TW TW088103929A patent/TW428360B/en not_active IP Right Cessation
- 1999-04-23 DE DE19918607A patent/DE19918607A1/en not_active Ceased
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20200036044A (en) * | 2015-07-29 | 2020-04-06 | 티디케이 일렉트로닉스 아게 | Frequency control method of piezoelectric transformer and switch arrangement structure including piezoelectric transformer |
| US10638590B2 (en) | 2015-07-29 | 2020-04-28 | Epcos Ag | Method for frequency control of a piezoelectric transformer and circuit arrangement comprising a piezoelectric transformer |
Also Published As
| Publication number | Publication date |
|---|---|
| TW428360B (en) | 2001-04-01 |
| JP2000188880A (en) | 2000-07-04 |
| DE19918607A1 (en) | 2000-07-06 |
| KR100325263B1 (en) | 2002-06-26 |
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