| 摘要 |
PROBLEM TO BE SOLVED: To enable optimum setting in realtime by measuring the magnitude of an input signal when the operation of a threshold value is indicated, calculat ing the threshold value based on the measurement value and setting it as the threshold value of an open/close device. SOLUTION: An open/close indicating signal is outputted from an open/close signal generator 3 whenever the input signal is inputted and supplied to a coefficient genenrating part 8. Thus, whenever the new open/close indicating signal is inputted, the more proper rise coefficient and fall coefficient are calculated based on the envelope waveform of the input signal at that time in the coefficient generating part 8. The coefficient which is held in the coefficient memory 7 as the calculated coefficient is updated. Therefore, the rise and fall characteristics of a gate waveform are set to the optimum ones in realtime by following the state change of the input signal. Then, when the connection of coefficient setting is indicated by a coefficient operating element, the coefficient R held in a register 811 is set as the rising coefficient K in the coefficient memory 7 and the coefficient R held in the register 812 is set as the falling coefficient K. |
