| 摘要 |
PURPOSE:To emphasize a high frequency of the amplitude characteristic of an amplitude change means by using resistors, capacitors and one amplifier so as to set a value (Q) representing the sharpness of the resonance of a low pass filter to be 1.0 or over. CONSTITUTION:For example, the resistance of a resistor 21 is set to 12.0KOMEGA, the resistance of a resistor 22 is set to 12.0KOMEGA, the capacitance of a capacitor 17 is set to 0.001muF, the capacitance of a capacitor 18 is set to 0.0018muF, the resistance of a resistor 19 is set to 39.0KOMEGA, and the resistance of a resistor 20 is set to 13.0KOMEGA, then a gain of 12dB is obtained for the entire frequency band with a Q set to 2.2. Moreover, the resistance of the resistors 21, 22 is set equal and the capacitance of the capacitors 17, 18 is set equal respectively, since the Q depends on the ratio of the resistance of the resistors 19, 20, the setting of the circuit constants is set simply. Thus, the amplitude characteristic emphasizing a high frequency signal component is formed. |
