Logah Technology Corp.

Logan Technology Corp.

Ho-Wen Chen

Cheng-Chia Hsu

Yu-Cheng Pan

Teng-Ho Wu

Teng-Kang Chang

An LCD backlight driving device with an isolating transformer 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 helps to effectively shorten a safety distance required for setting up said driver transformer; the present invention uses said isolating transformer to shorten the safety distance required than that of using said driver transformer directly and to decrease an area in implementing a circuit board and to cut cost of said device.

LCD backlight driving device with an isolating transformer

A double frequency signal generator to which a synchronization signal having a duty cycle of 1% to 999% is inputted. The synchronization signal is used for triggering of a switching component at positive and negative edges to generate a triangular-wave signal. An average of voltages of the triangular-wave signal is acquired and compared with the triangular-wave signal at a comparator to generate a square-wave having a duty cycle of 50%. Then, the square-wave signal is used for triggering at positive and negative edges to generate a double frequency signal. As such, the high cost issue and the limitation of a square-wave input signal occurred in the prior art may be efficiently overcome.

Double frequency signal generator

A bridge type phase detection device comprises one or more than one transformer, a plurality of tubes, a voltage-detecting protection circuit and a first, second and third impedance, wherein a first tube of said plurality of tubes has a phase opposite to that of a second tube of said plurality of tubes, and a first end of said first impedance coupling with a secondary side of said transformer and a first end of said first tube, a first end of said second impedance coupling with said secondary side of said transformer and a first end of said second tube, then a second end of said first impedance connecting to a second end of said second impedance to form a detection point, said detection point coupling with said third impedance and said voltage-detecting protection circuit; said detection point having a voltage value derived from calculating a sum of said phase of said first impedance and that of said second impedance, then an output voltage divided among said first, two and third impedance, resulting in approximately zero voltage at said detection point during normal operation, if said voltage-detecting protection circuit detecting a non-zero voltage, it is concluded that a tube anomaly is present.

Growing community of inventors

Taipei County, Taiwan

Ho-Wen Chen