| 摘要 |
PURPOSE:To obtain resonance characteristics without increasing the capacity of an ROM for coefficient storage by giving amplitude caracteristics a peak by increasing or decreasing some of coefficients of a transfer function. 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 coefficients b1 and b2. An arithmetic circuit 11 operaters the coefficient b2 supplied from the ROM6' to calculate a coefficient b2n, which is supplied to a multiplier 8. 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. An 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. |
