| 摘要 |
PURPOSE:To obtain resonance characteristics without increasing the capacity of an ROM by increasing or decreasing some of coefficients of a transfer function and by making a gain adjustment of amplitude characteristics by operating the other coefficients. CONSTITUTION:In an ROM6', coefficients b1 and b2 are stored which correspond to cutoff frequencies, and a coefficient K to be supplied to a multiplier 9 is calculated by an arithmetic circuit 10 by using the coefficient b1 and the output coefficient b2n of an arithmetic circuit 11. The circuit 11 operates the coefficient b2 to calculate the coefficient b2n and then supplies it to a multiplier 8 and the circuit 10. The outputs of multipliers 4 and 8 are subtracted from and added to an input signal by an adder 1 and to the output of the adder 1, the outputs of a multiplier 5 and a delay circuit 5 are added by an adder 2. The output of the adder 2 is multiplied by K at the multiplier 9 to obtain an output signal. As a result, the cutoff frequency is equivalent to the resonance frequency of this device and according to combinations of logical levels of control signals n-infinity , n0 and n1 supplied to the circuit 11, the depth of a resonance level is controlled. |
