Document Type and Number:
Japanese Patent JPS4947576
Kind Code:
B1
Abstract:
1,261,174. Active filters. WESTERN ELECTRIC CO. Inc. 27 Jan., 1970 [1 May, 1969], No. 3859/70. Heading H3U. A filter comprises: means 11-1, 11-2 ... 11-N for modulating an input signal; means 17 for deriving multiplexed sample pulses from the modulated signal; a digital filter 19 for filtering the multiplexed samples; means 21 for demultiplexing the filtered signal; and means 13-1, 13-2 ... 13-N for demodulating the demultiplexed signals. The modulator and multiplexer, Fig. 5 (not shown) comprises an operational amplifier (31) which has its transmission characteristics altered in a predetermined manner by switching transistors controlled by a logic circuit, Fig. 10 (not shown). The demultiplexed signals are sequentially switched to smoothing circuits C1 ... CN by switches 23a, 23b.
Application Number:
JP779970A
Publication Date:
December 17, 1974
Filing Date:
January 30, 1970
Export Citation:
International Classes:
H03H19/00; (IPC1-7): H03H11/00