Patent Application
20080165114
1. Field of the Invention
The present invention relates to an LCD backlight driving device with an isolating transformer and more particularly to an LCD backlight driving device using an isolating transformer to reduce the manufacturing cost of the LCD backlight driving device.
2. Description of the Prior Art
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Therefore, the above-mentioned implementation of a prior-art LCD backlight driving device presents several shortcomings.
In view of the above-described deficiencies of prior-art LCD backlight driving device, after years of constant effort in research, the inventors of this invention have consequently developed and proposed an LCD backlight driving device with an isolating transformer in the present invention.
It is an object of the present invention to provide an LCD backlight driving device with an isolating transformer to effectively shorten the safety distance required in implementing the driver transformer and to further reduce the area of the circuit board and to cut the manufacturing cost of the device.
It is another object of the present invention to provide an LCD backlight driving device with an isolating transformer to improve the stability in using the device, to extend the product lifetime, to cut back the transformer size and to save space.
The LCD backlight driving device with an isolating transformer of the present invention comprises a DC power supply, a square wave generator, a square wave controller, said isolating transformer and a driver transformer; wherein said isolating transformer has a primary side connected to said square wave generator and a secondary side connected to said driver transformer. Since said isolating transformer is placed between said square wave generator and said driver transformer, it effectively shortens a safety distance required for setting up said driver transformer, as compared to when said driver transformer is used directly; as a result, the area for implementing a circuit board is decreased and the manufacturing cost of said device is reduced.
These features and advantages of the present invention will be fully understood and appreciated from the following detailed description of the accompanying Drawings.
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a DC power supply 21 for outputting a DC signal to a square wave generator 22;
the square wave generator 22 for converting the DC signal into an AC signal and outputting the AC signal to a primary side of a isolating transformer 24;
a square wave controller 23 for outputting a control signal to the square wave generator 22;
the isolating transformer 24 for receiving the AC signal from the square wave generator 22, and then outputting the AC signal, from a secondary side of the isolating transformer 24, to a primary side of a driver transformer 25; and
the driver transformer 25 for boosting the AC signal inputted from the isolating transformer 24, and then outputting a boosted AC signal, from a secondary side of the driver transformer 25, to a lamp 26.
For an input voltage of 400V at the primary side of the isolating transformer 24, an output voltage at the secondary side of the isolating transformer 24 will be less than 400V. Therefore the safety spacing between the primary side and the secondary side of the isolating transformer 24 is only 6 mm. Thus, the isolating transformer effectively shortens the safety distance required, as compared to when said driver transformer is used directly; as a result, the area for implementing a circuit board is decreased and the manufacturing cost of the device is reduced.
Please refer to
a DC power supply 21 for outputting a DC signal to a square wave generator 22;
the square wave generator 22 for converting the DC signal into an AC signal and outputting the AC signal to a primary side of a isolating transformer 24;
the isolating transformer 24 for receiving the AC signal from the square wave generator 22, and then outputting the AC signal, from a secondary side of the isolating transformer 24, to a primary side of a driver transformer 25; and
the driver transformer 25 for boosting the AC signal inputted from the isolating transformer 24, and then outputting a boosted AC signal, from a secondary side of the driver transformer 25, to a lamp 26.
Please refer to
a DC power supply 21 for outputting a DC signal to a square wave generator 22;
the square wave generator 22 for converting the DC signal into an AC signal and outputting the AC signal to a primary side of the isolating transformer 24;
a square wave controller 23 for outputting a control signal to the square wave generator 22;
the isolating transformer 24 for receiving the AC signal from the square wave generator 22, and then outputting the AC signal, from a secondary side of the isolating transformer 24, to primary sides of a plurality of driver transformers 25; and
the plurality of driver transformers 25 for boosting the AC signal inputted from the isolating transformer 24, and then outputting the boosted AC signal, from secondary sides of the plurality of driver transformers 25, to a plurality of lamps.
In the embodiments of the present invention, the isolating transformer 24 can have a capacitor implemented at its primary side or secondary side to prevent interference of a DC current.
The present invention discloses an LCD backlight driving device with an isolating transformer which, while compared with conventional techniques, is advantageous in the following respects:
1. The present invention provides an LCD backlight driving device with an isolating transformer to effectively shorten the safety distance required for implementing the driver transformer and to further reduce the area of the circuit board and to cut the manufacturing cost of the device.
2. The present invention provides an LCD backlight driving device with an isolating transformer to improve the stability in using the device, to extend the product lifetime, to cut back the transformer size and to save space.
Many changes and modifications in the above described embodiments of the invention can, of course, be carried out without departing from the scope thereof. Accordingly, to promote the progress in science and the useful arts, the invention is disclosed and is intended to be limited only by the scope of the appended claims.
