| 摘要 |
PURPOSE:To miniaturize the titled unit and to lighten a weight by generating a DC by using a high frequency, and generating the AC of a calling signal by an oscillator whose frequency is equal to that of the calling signal, and a semiconductor element. CONSTITUTION:An intermitting part 1 intermits a current by a battery B1, makes the intermittent current of a high frequency conduct to the primary side winding n1 of a transformer T1, and the AC of a high voltage required for a calling signal is induced in secondary windings n2, n3 of the transformer T1. This AC is rectified and smoothed by generating circuits 7, 8, and two DCs whose polarity is opposite to each other are generated. Semiconductors 2,3 inserted in series into each output of the generating circuits 7, 8 are controlled alternately at every half period by the sine wave output signal of a fundamental oscillator 4, and by this control, the outputs of the generating circuits 7,8, which becomes the currents of a sine half wave are superposed so as to become an opposite polarity to each other. In this way, since a voltage conversion by a high frequency is executed, the transformer can be made small in size and light in weight.
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