CN101494942A - Piezoelectric oscillator for high voltage lighting - Google Patents

Abstract

The present invention is a piezoelectric oscillator for high-voltage lighting, which connects a piezoelectric capacitor in parallel with an LC resonant circuit to output power. The LC resonant circuit is used to generate resonance, and utilizes the inverse piezoelectric effect generated by the piezoelectric capacitor when it is energized and deformed, and the positive charge generated by the positive piezoelectric effect after the deformation, which has the effect of amplifying the voltage, thereby saving power consumption and reducing production costs.

Description

Piezoelectric Oscillators for High Voltage Lighting

technical field

The present invention relates to a high-voltage lighting, in particular to a piezoelectric oscillator for high-voltage lighting.

Background technique

The luminescence principle of Cold Cathode Fluorescent Lamp (CCFL) is similar to that of ordinary fluorescent lamps. Its luminescence principle is that when high voltage is input from the electrode end, a small number of electron molecules in the tube hit the electrode at high speed, and secondary electron emission is generated at this time. When the discharge starts, electrons collide with mercury atoms, and the mercury atoms are excited to emit 253.7nm ultraviolet light. The ultraviolet light excites the phosphor powder coated on the tube wall to produce visible light with relative color temperature. In addition to being widely used in monitors, personal digital assistants, digital cameras and mobile phones, etc., it is also one of the indispensable backlight materials for liquid crystal displays. Because cold cathode fluorescent lamps do not use filaments, there is no problem of filament burnout, so they have a very reliable service life. Using this kind of lamp as a lighting source has high luminous efficiency, small diameter, high luminance, less heat, and long life. Long and other advantages.

In order to meet the requirements of small size and good electrical performance, the lighting circuit of the cold cathode lamp adopts a piezoelectric transformer (piezoelectric transformer) instead of a coil type step-up transformer. Piezoelectric transformers have superior electrical characteristics such as small size, high voltage gain, high efficiency, good insulation and no electromagnetic interference. Therefore, piezoelectric transformers are generally used in the lighting circuit of high-luminous-efficiency lighting systems, which can achieve short, light, thin and superior electrical performance.

However, in order to make the piezoelectric transformer provide a larger output power, in addition to increasing the size, the easiest way is to increase the area of the silver electrode surface, but the larger the area of the silver electrode surface, there will be a reduction in the step-up ratio. The effect makes the effect of increasing the output power that was originally expected to be ineffective. In addition to increasing the cost, increasing the size also runs counter to the desire to be thin, light and short.

Contents of the invention

In view of the above problems, the main purpose of the present invention is to provide a piezoelectric oscillator for high-voltage lighting, which uses a piezoelectric capacitor with a simple structure and an LC resonant circuit to achieve high power output, thereby reducing power consumption and production costs. , extremely competitive in the market.

Another object of the present invention is to provide a piezoelectric oscillator for high-voltage lighting, which uses the piezoelectric effect of the piezoelectric capacitor under the LC resonant circuit to exert an automatic protection mechanism when the load is overloaded to avoid failure and overheating danger.

Therefore, in order to achieve the above purpose, the piezoelectric oscillator for high-voltage lighting disclosed by the present invention is to apply the high-power piezoelectric oscillator originally used in the ultrasonic oscillator to the ballast and commutator for high-voltage lighting. As a piezoelectric capacitor in the device, this piezoelectric capacitor can produce an inverse piezoelectric effect when it is energized and deformed, and a positive piezoelectric effect will be generated after deformation, so that positive charges will be generated, which will have the effect of amplifying the voltage and achieve high power output. It eliminates the shortcomings of traditional piezoelectric transformers that only provide high voltage, low current and limited power output.

And the present invention matches the piezoelectric capacitor with the LC resonant circuit. When the LC resonant circuit resonates, it can exert the best output performance, and when the load is overloaded, the temperature of the piezoelectric capacitor will rise and the capacitance value will increase, making the LC resonant circuit Resonance cannot be generated, the output efficiency becomes smaller, and it has an automatic protection function.

In addition, in the present invention, the piezoelectric capacitor can be matched with the LC resonant circuit, and an auxiliary capacitor with a capacitance equivalent to that of the piezoelectric capacitor can also be selected for matching. When the LC resonant circuit is in resonance, the piezoelectric effect is improved to achieve Output power optimization.

Description of drawings

Fig. 1 is a schematic diagram of a piezoelectric oscillator for high-voltage lighting provided by an embodiment of the present invention;

Fig. 2 is the schematic diagram of the piezoelectric capacitor provided by the embodiment of the present invention;

FIG. 3 is a schematic diagram of a piezoelectric capacitor provided by another embodiment of the present invention.

Explanation of reference signs: 10-piezoelectric capacitor; 11-circular plate substrate; 12-conductive layer; 121-electrode pin; 13-conductive layer; 131-electrode pin; 20-LC resonant circuit; 30 auxiliary capacitor; 40-piezoelectric capacitor; 50-lead wire.

Detailed ways

The above and other technical features and advantages of the present invention will be described in more detail below in conjunction with the accompanying drawings.

Please refer to FIG. 1 , which is a schematic diagram of a piezoelectric oscillator for high-voltage lighting provided by an embodiment of the present invention, mainly including a capacitor 10 , an LC resonant circuit 20 and an auxiliary capacitor 30 connected in parallel. The capacitor 10 used in the piezoelectric oscillator is a piezoelectric capacitor, which is used to store electric energy and has piezoelectric characteristics. It can adjust the power factor and then output the power. When it is energized and deformed, it will produce an inverse piezoelectric effect, and after deformation, it will produce a positive pressure Electric effect, and the conversion of its positive and negative piezoelectric effects will generate positive charges, which will amplify the voltage and have the effect of amplifying the voltage to achieve high power output. In this embodiment, the piezoelectric capacitor 10 is used to generate resonance The LC resonant circuit 20, when the LC resonant circuit 20 resonates, can produce the best output performance.

Since the capacitance value of piezoelectric capacitor 10 is mainly affected by temperature, its output voltage will change under the condition of constant current. The capacitance value is equivalent to the capacitance value of the variable voltage capacitor 10, which is used for auxiliary charging, so as to optimize the output power of the piezoelectric effect. When the light is turned on, the voltage will rise instantly, and the capacitance value will be properly matched after the light is turned on, so the output will be adjusted according to the piezoelectric effect, which can reduce additional power consumption.

As shown in Figure 2, the piezoelectric capacitor 10 of the present embodiment is to make a disc base material 11 with piezoelectric material, and then make the same circular conductive layers 12, 13 on the circle with silver glue, copper paste or nickel paste. The entire or part of the upper surface and the lower surface of the substrate 11 constitute the two poles of the piezoelectric capacitor 10 , and electrode pins 121 , 131 are welded on the outer sides of the conductive layers 12 , 13 to connect the LC resonant circuit 20 . In this embodiment, a piezoelectric capacitor 10 is used, which can output up to 70 watts of power. It only needs to be matched with a half-bridge resonant circuit, which can reduce production costs and has the advantage of price competition. Of course, if it is matched with a full-bridge resonant circuit Can drive also high power output. Furthermore, if the piezoelectric capacitor 10 is matched with an L-impedance type LC resonant circuit, it has an automatic protection function, and the resonance output can be changed due to the increase of the capacitance value when the load is overloaded, and the output power is reduced, so that the temperature is lowered; 10 has piezoelectric characteristics. Once the load is overloaded, its temperature rises and the capacitance value becomes larger, which makes the capacitance value inside the LC resonant circuit change, so that resonance cannot be generated, the output efficiency becomes smaller, and the lamp dims accordingly. Avoid the risk of malfunction and overheating.

In addition, as shown in FIG. 3, another embodiment of the present invention is to use two piezoelectric capacitors 10, 40 connected up and down through a lead wire 50. In practice, the piezoelectric capacitors can be connected in series or in parallel. The disc substrate 11 and the corresponding two conductive layers 12, 13 (the piezoelectric capacitors 10, 40 have the same structure, so only the piezoelectric capacitor 10 is represented). As the capacitance value increases, the inductance value increases, the power generated after resonance will also increase, and the output power can reach up to 100 watts, while the temperature can be maintained at about 30°C. This also means that the piezoelectric capacitor of this embodiment can provide multiple times higher output power than the conventional piezoelectric transformer, and there is no problem of overheating.

The above descriptions are only preferred embodiments of the present invention, and are only illustrative rather than restrictive to the present invention. Those skilled in the art understand that many changes, modifications, and even equivalents can be made within the spirit and scope defined by the claims of the present invention, but all will fall within the protection scope of the present invention.

Claims (8)

1, a kind ofly be used for the piezoelectric oscillator that high pressure is lit a lamp, it comprises a capacitor and a LC resonant circuit, it is characterized in that:

Described capacitor is a piezoelectric, and in parallel with described LC resonant circuit, and described piezoelectric includes:

One plectane base material, it has upper surface and lower surface, is the piezoelectricity material; With

Two conductive layers, it is respectively formed at the upper surface and the lower surface of described plectane base material, and constitutes the two poles of the earth of described piezoelectric.

2, according to claim 1ly be used for the piezoelectric oscillator that high pressure is lit a lamp, it is characterized in that: also comprise an auxiliary capacitor, be connected in parallel between described piezoelectric and the described LC resonant circuit.

3, according to claim 2ly be used for the piezoelectric oscillator that high pressure is lit a lamp, it is characterized in that: the capacitance of described auxiliary capacitor is suitable with the capacitance of described piezoelectric.

4, according to claim 1ly be used for the piezoelectric oscillator that high pressure is lit a lamp, it is characterized in that: described LC resonant circuit is made of half-bridge resonance circuit or full-bridge resonant circuit.

5, according to claim 1ly be used for the piezoelectric oscillator that high pressure is lit a lamp, it is characterized in that: the described two conductive layers outside also respectively welding be provided with an electrode pin, to connect described LC resonant circuit.

6, according to claim 5ly be used for the piezoelectric oscillator that high pressure is lit a lamp, it is characterized in that: described plectane base material and described two conductive layers are two groups, and by the serial or parallel connection in addition that goes between.

7, according to claim 1ly be used for the piezoelectric oscillator that high pressure is lit a lamp, it is characterized in that: described two conductive layers are for circular, and are respectively formed at the upper surface and the lower surface of the whole of described plectane base material or part.

8, according to claim 1ly be used for the piezoelectric oscillator that high pressure is lit a lamp, it is characterized in that: described two conductive layers are formed by elargol, copper cream or nickel cream.

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