| 摘要 |
PURPOSE:To eliminate the unnaturality at switching, by switching the coefficients of a transfer function prestored with a signal in a digital filter device. CONSTITUTION:A digital filter device consists of adders 1, 2, multipliers 4, 5, 8, 9, 10, ROM6 storing the coefficients of the transfer function, a coincidence detecting circuit 11 and a latch 16. The ROM6 is designated for the address with the cut-off frequency data from the latch 16 and applies coefficients a1, a2, b1, b2, (k) to the multipliers 4, 5, 8, 9, 10. In changing the coefficients, a cut-off frequency data is stored in the latch 16 with a read-in control signal R from the coincidence circuit 11, the output makes the address designation of the ROM6 and new coefficients are applied to the multipliers 4, 5, 8, 9, 10. Thus, the transient effect at coefficient switching can be decreased. |
