| 摘要 |
PURPOSE:To eliminate the level regulation of a triangular wave and to obviate the regulation of a circuit by providing PWM conversion ration comparators for positive and negative command inputs, combining comparison signals from the two comparators by a logic circuit, and distributing it into an absolute value PWM signal and a voltage direction signal. CONSTITUTION:An input terminal (12) for a command input having a level 0-+ or -100%, first and second comparators 13, 17, a triangular wave generator 18, an inverter 23 so connected to the generator 18 as to invert the output of the generator 18, and a logic circuit 24 connected to a comparator output terminal (4) are provided. A command input from the terminal (12) and the output of the generator 18 are respectively input to + and. input terminals (2) of the comparator 13, and the command input from the terminal (12) and the output of the inverter 23 are respectively input to + and - input terminals (3) of the comparator 17. Thus, comparison output signals from the comparators 13, 17 are combined by the circuit 24, it is distributed to an absolute value PWM signal and voltage direction signal responsive to the command input and output. |
