| 摘要 |
PURPOSE:To allow the effective filtering of the signals of resembling frequency characteristics by adjusting one of the currents of integrators to obtain a 1st filter characteristic and changing the one current at the same ratio to obtain a 2nd filter characteristic. CONSTITUTION:A filter circuit 1 is combined with the two integrators GAA, GAB and the time constants omega1, omega2 are changed according to the ratios of two currents I1A, I1B and I2A, I2B to be supplied by which the filter characteristics are determined. The 1st filter characteristic is obtd. by adjusting either of the 1st or 2nd currents I1A, I1B or I2A, I2B. The one of the 1st or 2nd currents is changed at the same ratio by which the 2nd filter characteristic is obtd. The effective filtering and transmitting of the signal components having the resembling frequency characteristics on a frequency axis are possible with the simple constitution in this way and this filter circuit is effectively used for a rotary head type DAT, etc. |
