Filter circuit
AssigneeYazaki Corporation
InventorsYuki CHIYAJO, Hidehiko SHIMIZU, Yasutaka WAKASUGI
Life of this patent
Estimating the term…
Abstract
By configuring low-pass filters each with a resistor and a capacitor, noise is removed. Based on a reference value of DC voltage that appears at output terminals of a battery pack circuit, a lowering portion of capacitance that arises in the respective capacitors is estimated in advance, and a compensation value is included in the resistance value of the respective resistors such that the cutoff frequencies of the low-pass filters are within an intended range. Even when a high voltage is handled, the variance in cutoff frequencies can be prevented from arising and the noise in an unnecessary frequency domain can be adequately reduced.
Claims6
A filter circuit connected between a battery pack circuit configured with battery cells of two or more connected in series and a certain voltage detection circuit, in order to detect voltages of output terminals at connection points of the respective battery cells by the voltage detection circuit, the filter circuit comprising:
- a plurality of sets of filter units each configured with a resistor connected between any one of the output terminals of the battery pack circuit and any one of a plurality of input terminals of the voltage detection circuit, and a capacitor connected between the any one of the input terminals of the voltage detection circuit and a ground terminal, wherein
- a resistance value of the resistor is determined so as to include a compensation resistance value necessary to compensate for an estimated lowering amount of capacitance that arises in the capacitor with respect to a reference value of DC voltage at the appropriate output terminal.
Dependencies are inferred from the claim text.