The low frequency signal processing circuit null from the analysis

摘要

PURPOSE:To obtain a circuit of simple constitution which processes the low frequency signal of an infrared analyzer, etc., at a high speed by shifting the phase of the low frequency signal supplied as an input by (n) parallel-connected branching circuit and adding outputs after shifting operation. CONSTITUTION:The circuit consists of (n-1) sets of phase adjusting parts 101-10n-1 which are equipped with full-wave rectifying parts 201-20n-1 at their output sides respectively and shift the phase of the input low frequency signal by pi/n (n: integer larger than two) differently, a full-wave rectifying part 20 which is connected in parallel to them and inputs low frequency signals, and an adding part 30 which adds the outputs of the full-wave rectifying parts 201-20n-1. Then, the low frequency signal is inputted to the (n) branching circuits in parallel, shifted in phase by pi/n by the (n-1) sets of the branching circuits respectively, and then rectified on full-wave basis. Their outputs are added 30 to the output obtained by rectifying the low frequency signal on full- wave as it is. The frequency of the composite output after the addition is (n) times as high as that of the original signal and the difference between the peak value and bottom value is reducible, so a time constant necessary for smoothing is decreased greatly and fast-response signal processing is performed.