Unlock instant, AI-driven research and patent intelligence for your innovation.

Piezoelectric transformer inverter

A technology for piezoelectric transformers and inverters, which is applied in the field of piezoelectric transformers and inverters, and can solve problems such as no advantages and large losses

Inactive Publication Date: 2004-09-29
MURATA MFG CO LTD
View PDF0 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In addition, the loss caused by the current flowing into the coil 14 is large, and there is no advantage over the method of inserting a chopper in terms of size and efficiency

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Piezoelectric transformer inverter
  • Piezoelectric transformer inverter
  • Piezoelectric transformer inverter

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0018] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0019] figure 1 is a block diagram of a piezoelectric transformer inverter according to an embodiment of the present invention. exist figure 1 Among them, the piezoelectric transformer inverter includes an inverter unit 20 and a step-down chopper unit 30 . The secondary electrode of the piezoelectric transformer 22 of the inverter unit 20 is connected to the cold cathode fluorescent tube 11 which is lit by the output voltage of the piezoelectric transformer 22 . The inverter unit 20 includes an inverter unit control circuit 21 , wherein the driving unit includes a series circuit composed of a coil 23 and a switching transistor 25 and a series circuit composed of a coil 24 and a switching transistor 26 .

[0020] In other words, the inverter unit control circuit 21 controls the driving frequency or driving efficiency of the control s...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The inverter unit includes a ceramic piezoelectric transformer, a drive unit, and an inverter control circuit. The step-down chopper unit includes a switching device, a free wheeling device, and a PWM feedback control circuit. In the piezoelectric transformer inverter, even when the feedback control by the PWM feedback control circuit is impossible, the on-duty of the chopper unit is restricted so that it is not greater than a given amount.

Description

technical field [0001] The present invention relates to piezoelectric transformer inverters, and more particularly, to piezoelectric transformer inverters for lighting cold cathode fluorescent tubes used in LCD panels such as notebook-sized personal computers. Background technique [0002] Examples of piezoelectric transformer inverters for lighting cold cathode fluorescent tubes in liquid crystal backlighting have been described in Japanese Unexamined Patent Publication No. 6-167694 and Japanese Unexamined Patent Publication No. 9-107684. In Japanese Unexamined Patent Publication No. 6-167694, the brightness of cold cathode fluorescent tubes is adjusted by controlling the tube current of the cold cathode fluorescent tubes for backlighting. In this case, the tube current can be controlled by utilizing the frequency step-up ratio characteristic of the piezoelectric transformer. For example, when a small amount of tube current is required or the input voltage is high, control...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): H02M7/48H02M7/538H02M7/539H05B41/24
CPCH02M7/53806
Inventor 野间隆嗣山胁一郎森岛靖之
Owner MURATA MFG CO LTD