| 摘要 |
PURPOSE:To remove problems on insulation from a protecting circuit and a control circuit, reduce voltages impressed on these circuits and permit miniaturization, by detecting the D.C. stage voltage of an inverter in an insulated form. CONSTITUTION:A D.C. stage voltage or the both terminals voltage of a smoothing capacitor 2 is impressed on the series circuit of a transistor 8 and a high-frequency transformer 9. An output is generated in the secondary side of the high-frequency transformer 9 by effecting ON-OFF control of the transistor 8. A diode 10' reftifies only the output voltage of the high-frequency transformer 9 in the ON period of the transistor 8 among the output voltages of the high-frequency transformer 9. Charging and discharging are effected by a time constant, determined by the smoothing capacitor 2'' and a resistor 5'' whereby a voltage, responding to the variation of the D.C. stage voltage, may be obtained. |
