Resistance Compensation
With ideal components there is no need to use resistors in the design of lattice filters. However, practical considerations of properties of real components leads to resistors being incorporated. Sections designed to equalise low audio frequencies will have larger inductors with a high number of turns. This results in significant resistance being in the inductive branches of the filter, which in turn causes attenuation at low frequencies.
In the example diagram, the resistors placed in series with the capacitors, R1, are made equal to the unwanted stray resistance present in the inductors. This ensures that the attenuation at high frequency is the same as the attenuation at low frequency and brings the filter back to a flat response. The purpose of the shunt resistors, R2, is to bring the image impedance of the filter back to the original design R0. The resulting filter is the equivalent of a box attenuator formed from the R1's and R2's connected in cascade with an ideal lattice filter as shown in the diagram.
Read more about this topic: Lattice Phase Equaliser
Famous quotes containing the words resistance and/or compensation:
“The free man is a warrior.—How is freedom measured among individuals, among peoples? According to the resistance that must be overcome, according to the trouble it takes to stay on top. The highest type of free man must be sought where the highest resistance is constantly overcome: five steps away from tyranny, close to the threshold of the danger of servitude.”
—Friedrich Nietzsche (1844–1900)
“In compensation for considerable disgust, despondency, and boredom—such as living in solitude without friends, books, duties, or passions necessarily entails—we are given those quarter-hours of deepest communion with ourselves and nature. Those who completely barricade themselves from boredom, barricade themselves from themselves as well: they will never get to drink the most refreshingly potent draught from the their own innermost fountain.”
—Friedrich Nietzsche (1844–1900)