Polarity inverting circuit

DETAILED DESCRIPTION It is an object of the present invention to provide a polarity inverting circuit which can stably and efficiently invert and switch the polarities of battery and ground signals in accordance with an interface condition with respect to a corresponding unit without influencing speech paths.
In order to achieve the above object, according to the present invention, there is provided a polarity inverting circuit for supplying one of first and second potentials to first and second signal lines in accordance with a polarity inversion control signal, comprising first output voltage transmission means, connected to the first signal line, for linearly changing an output voltage from the first potential to the second potential, second output voltage transmission means, connected to the second signal line, for linearly changing an output voltage from the second potential to the first potential when an output voltage from the first output voltage transmission means reaches the second potential, first connection means for connecting the first signal line to a second potential source when the output from the first output voltage transmission means substantially reaches the second potential, second connection means for disconnecting the second signal from the second potential source when the first connection means is connected to the second potential source, first and second polarity switching time changing means, connected to the first and second output voltage transmission means, for changing corresponding rates of changes in output voltage, and control means for controlling operations of the first and second output voltage transmission means and of the first and second connection means.