| 摘要 |
PURPOSE:To invert the polarity of a battery and ground stably and efficiently without giving effect onto a talking path by providing a means increasing/ decreasing an output voltage of the battery linearly independently of a load, a polarity switching time variable means and a changeover control means. CONSTITUTION:When an output of a switch circuit (TB-SW) 3 is close to an open state, a switch circuit (TG-SW) 4 is conductive with a control signal from the (TB-SW)3 and an earth level is sent to a line T. When an SW control circuit 5 detects it that an output of a line T -48V sending switch circuit TB-SW3 reaches close to an open state, the circuit 5 changes linearly the output of an line R -48V sending switch circuit RB-SW1 from an open level (G level) to -48V through an RB integration circuit 6 and turns off a line R -48V sending switch circuit RG-SW2 and opens an output of the RG-SW2. Thus, the polarity is inverted from the state of G level of the line R and -48V of the line T into the state of -48V of the line R and G level of the line T. |
