| 摘要 |
PURPOSE: The horizontal polarizing apparatus is provided to reduce the switching loss of a transistor by supplying or precluding a constant current to a base end so that the transistor can operate in a complete switch mode. CONSTITUTION: The horizontal polarizing apparatus include a switching control unit having a comparator, for comparing a reference voltage connected to a non-inverting terminal and a signal inputted to an inverting terminal from the outside to remove noise. A switching unit(720) includes the first switch(QA) and the grounded second switch(QB) and drives one of the first and second switches depending on the output of the switching control unit. A base current supply unit(730) includes a diode(Da), a diode(Db) and a capacitor(C). If a base current(iB) is inputted via the switching unit(720), the diode(Da) and the diode(Db) are turned on, so that the capacitor(C) is charged with charges corresponding to a forward voltage drop of the diode(Da) and the diode(Db). Also, if there is no signal from the switching unit(720), charges in the capacitor(C) are rapidly discharged while a base current(iB) of an opposite direction is generated, thus rapidly turning off the transistor(Q2).
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