POWER SUPPLY, DISCHARGE LAMP OPERATING DEVICE AND ILLUMINATING DEVICE

Japanese Patent JP3553266

B2

PROBLEM TO BE SOLVED: To attain the control which gives an appropriate gain when loaded and not loaded by comparing the detected value of a voltage change between the output terminals of a power circuit with a reference value, and switching the gain of inverter circuit based on whether it is in excess of the reference value or not.
SOLUTION: In a control switching circuit 21, R5, R6 for detecting the value of voltage VDC between output terminals, and a detecting part 22 constituted for a power dividing circuit with a capacitor C5 are provided. When loading, detected voltage is lower than reference voltage VREF, therefore, a transistor Q2 is operated to indicate a resistance value corresponding to the detected voltage. The voltage determined by the power dividing ratio of (a resistor R7, the resistance value of the transistor Q2 and a resistor R8), and a resistor R9 is supplied between the gate and source of a transistor Q1 to give an appropriate gain. On the other hand, when no-loading, the detected voltage becomes higher than the reference voltage, therefore, the transistor Q2 is turned off, and controlled with fixed voltage determined by the power dividing ratio of the resistors R8, R9 between the gate of transistor Q1 and the source. It is thus possible to make control appropriately both in loading and no-loading.

Noriyuki Kitamura

JP10902596A

August 11, 2004

April 30, 1996

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Toshiba Lighting & Technology Corporation

H05B41/24; H02M7/48; H02M7/5387; (IPC1-7): H02M7/48; H02M7/5387; H05B41/24

JP8098555A
JP7272880A
JP5095684A

Akira Kashiwagi
Shinji Kashiwagi

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