CN100370885C - piezoelectric type conversion driving device - Google Patents

Abstract

A piezoelectric conversion driving device is used for components or products which need to be driven at high voltage or low voltage. The device comprises: the drive unit, the conversion unit and the piezoelectric units are synchronously driven by utilizing the single Pulse Width Modulation (PWM) unit to output signals with same phase and frequency so as to drive the loads to act simultaneously.

Description

Piezoelectric conversion drive

technical field

The invention relates to a piezoelectric conversion driving device, in particular to a piezoelectric conversion driving device which uses a single pulse width modulation (PWM) control unit to synchronously drive multiple driving units, conversion units, piezoelectric units and loads.

Background technique

The light source required for the liquid crystal display (LCD) used in commercially available desktop and notebook computers, PDAs, and Webpads is driven by a driving device to drive cold cathode lamps (CCFL) with high voltage, so that the light is projected to the backlight panel. The user can clearly see the displayed picture.

Especially for LCD TVs or LCD displays with additional touch film, higher brightness is required to compensate for visual requirements. A general drive device for driving cold cathode lamps is shown in Figure 1. This device uses a single pulse width modulation (PWM) control unit to drive a single drive unit, and then uses a single drive unit to drive a transformer and a load (cold cathode lamp). The cold cathode lamp uses high voltage to light the lamp. When the tube current is higher, the brightness is brighter.

When the brightness and uniformity of the backlight are insufficient, multiple lamps are often used. At this time, the number of pulse width modulation control units, drive units, and transformers for driving and lighting also increases, resulting in larger circuit boards, resulting in difficulty in production and cost. Increase.

Contents of the invention

The main purpose of the present invention is to solve the defects of the above-mentioned prior art and avoid the existence of the defects. The present invention uses a single pulse width modulation (PWM) control unit to drive multiple drive units, conversion units, piezoelectric units and loads, reducing the number of parts and reducing the size of the circuit board, making it easier to manufacture, and the relative manufacturing cost also follows reduce.

In order to achieve the above-mentioned purpose, the piezoelectric conversion driving device of the present invention includes: a pulse width modulation (PWM) control unit, a plurality of drive units, a plurality of conversion units, a plurality of piezoelectric units, and a plurality of loads, Using the aforementioned single pulse width modulation (PWM) control unit to output signals with the same phase and same frequency, multiple drive units, multiple conversion units, and multiple piezoelectric units are synchronously driven to drive multiple loads to act simultaneously.

Description of drawings

The technical content and detailed description of the present invention are described as follows in conjunction with the accompanying drawings.

FIG. 1 is a schematic circuit block diagram of a conventional piezoelectric switching drive device.

Fig. 2 is a schematic block diagram of the first embodiment of the present invention.

Fig. 3 is a schematic block diagram of the second embodiment of the present invention.

Fig. 4 is a schematic block diagram of a third embodiment of the present invention.

Detailed ways

Referring to Fig. 2, it is a schematic diagram of the first embodiment of the present invention. As shown in the figure: the piezoelectric conversion driving device of the present invention is used for components or products that need to be driven by high voltage or low voltage. This device includes: a pulse width modulation (PWM) control unit 1, a plurality of A wide modulation (PWM) control unit 1 is connected to a drive unit 2 driven synchronously, a plurality of conversion units 3 connected to the aforementioned plurality of drive units 2 and driven synchronously, and a plurality of conversion units 3 connected to the aforementioned plurality of conversion units 3 and driven synchronously. The piezoelectric unit 4 driven synchronously, and a plurality of loads 5 connected to the aforementioned piezoelectric unit 4 and synchronously driven, use a single pulse width modulation (PWM) control unit 1 to output signals of the same phase and same frequency, and synchronously drive multiple A driving unit 2, a plurality of conversion units 3, and a plurality of piezoelectric units 4 are used to drive a plurality of loads 5 to act simultaneously. Since the number of parts is reduced, the circuit board is reduced, which makes the production easier, and the relative production cost is also reduced.

The above-mentioned pulse width modulation (PWM) control unit 1 is used to output signals of the same phase and same frequency after being activated by an external power supply unit (not shown in the figure), and to drive multiple drive units 2 synchronously.

The plurality of driving units 2 are composed of a MOS metal oxide semiconductor element, and after being driven by the same phase and same frequency signal output by the above-mentioned pulse width modulation (PWM) control unit 1, a driving signal output will be generated.

Among the plurality of conversion units 3 , each conversion unit 3 is composed of an inductor for converting the signal output by the driving unit 2 .

Among the plurality of piezoelectric units 4, each piezoelectric unit 4 is composed of any one of a single plate, a laminated piezoelectric sheet, or a transformer, and can be used as an output for boosting and stepping down. 4. Connect a voltage feedback to the above-mentioned pulse width modulation (PWM) control unit 1, and any load 5 connects a current feedback to the pulse width modulation (PWM) control unit 1 to feed back a current, so that the pulse The PWM control unit 1 can sense the current of the load 5 so that the PWM control unit 1 can control the average current of the load 5 .

The multiple loads 5 are composed of components or products that need to be driven by high voltage or low voltage, such as cold cathode fluorescent lamps, ozone generators, negative ion generators, etc.

When the device is started, the pulse width modulation (PWM) control unit 1 outputs signals with the same phase and frequency, and synchronously drives multiple drive units 2 to act. After the conversion unit 3 is converted, it can drive multiple piezoelectric units 4, so that each piezoelectric unit 4 drives each load 5 to act; at the same time, the load 5 is connected with a current feedback to the pulse width modulation (PWM) control unit 1 sensing the current of the load 5, so that the pulse width modulation (PWM) control unit 1 can control the average current of the load 5, so that the load 5 can be driven on average.

Referring to Fig. 3, it is a schematic diagram of the second embodiment of the present invention. As shown in the figure: this embodiment is roughly the same as the above-mentioned embodiment, the difference is that after a single pulse width modulation (PWM) control unit 1a drives a plurality of drive units 2a, two-way drive unit 2a, conversion unit 3a and piezoelectric unit 4a to drive a single load 5a. At the same time, the two piezoelectric units 4a output a pair of voltages with opposite phases to the load 5a, which can obtain the characteristics of uniform output current, larger power output and better impedance matching. A single pulse width modulation (PWM) control unit 1a can be used. Simultaneously drive multiple sets of loads 5a.

Referring to FIG. 4 , it is a schematic diagram of a third embodiment of the present invention. As shown in the figure: this embodiment is roughly the same as the above two embodiments, the difference is that after a single pulse width modulation (PWM) control unit 1b drives multiple drive units 2b, then a single drive unit 2b is used to drive two circuits The conversion unit 3b, the piezoelectric unit 4b and the load 5b. The number of parts used in the piezoelectric conversion driving device is reduced, so that the manufacture is easier and the manufacturing cost can be greatly reduced.

Claims (8)

1. piezoelectric type conversion driving device is characterized in that this device includes:

One pulse-width modulation control unit (1) is in order to the signal of output same-phase and same frequency;

A plurality of driver elements (2) are connected with above-mentioned pulse-width modulation control unit (1), be subjected to simultaneously pulse-width modulation control unit (1) the signal Synchronization of the same-phase of exporting and same frequency drive;

A plurality of converting units (3), connect one to one with above-mentioned a plurality of driver elements (2), or two converting units (3) in above-mentioned a plurality of converting unit (3) are connected with a driver element (2) in above-mentioned a plurality of driver elements (2), and the drive signal that exported by driver element (2) drives;

A plurality of piezoelectric units (4) connect one to one with above-mentioned a plurality of converting units (3), and the signal that exported by converting unit (3) drives;

A plurality of loads (5), connect one to one with above-mentioned a plurality of piezoelectric units (4), or the load (5) in above-mentioned a plurality of load (5) is connected with two piezoelectric units (4) in above-mentioned a plurality of piezoelectric units (4), and the signal that exported by piezoelectric unit (4) drives.

2. piezoelectric type conversion driving device according to claim 1 is characterized in that, this piezoelectric unit (4) adopts any structural design of individual layer or lamination.

3. piezoelectric type conversion driving device according to claim 1 is characterized in that this converting unit (3) is made of inductance.

4. piezoelectric type conversion driving device according to claim 1 is characterized in that, this driver element (2) is made of a MOS metal-oxide semiconductor element.

5. piezoelectric type conversion driving device according to claim 1 is characterized in that this load is any in cold cathode fluorescent lamp pipe, ozone generation device, the anion generator.

6. piezoelectric type conversion driving device according to claim 1, it is characterized in that, after driving a plurality of driver elements (2) with single pulse-width modulation control unit (1), utilize driver element (2), converting unit (3) and the piezoelectric unit (4) of two-way to drive single load (5).

7. piezoelectric type conversion driving device according to claim 6 is characterized in that, this two piezoelectric unit (4) is exported the opposite voltage of a pair of phase place to load (5).

8. piezoelectric type conversion driving device according to claim 1, it is characterized in that, after driving a plurality of driver elements (2) with single pulse-width modulation control unit (1), utilize single driver element (2) to drive converting unit (3), piezoelectric unit (4) and the load (5) of two-way again.

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