US 4,289,981 AGranted

Pulsive component detecting apparatus

AssigneesSanyo Electric Co., Ltd., Tokyo Sanyo Electric Co., Ltd.

InventorsJunji Sakamoto, Hiroyasu Kishi

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Abstract

An input signal including a pulsive noise such as an ignition noise in superposition on a continuous noise such as a white noise is applied commonly to the base electrodes of a pair of transistors of the same conductivity type implementing a differential amplifier. The amplified signal is applied to first and second rectifying circuits for full-wave rectification. The output of the first rectifying circuit is detected by a detecting circuit. The output of the second rectifying circuit is applied to a pulsive noise detecting circuit for detection of a pulsive component. The ratio of the detecting level of the detecting circuit to the detecting level of the pulsive noise detecting circuit is determined for avoiding malfunction of the pulsive component detecting circuit by virtue of the continuous noise.

Claims17

Dependent claims

An apparatus for detecting a pulsive component in an input signal including a pulsive component in superposition on a continuous component, comprising:

amplifying means for amplifying said input signal,
rectifying means responsive to the output of said amplifying means for rectifying the output of said amplifying means,
detecting means responsive to the output of said rectifying means for detecting at a first detecting level the output of said rectifying means for providing a control signal associated with the level of said continuous component of said input signal,
limiting means responsive to said control signal obtained from said detecting means for limiting the amplitude of said input signal being applied to said amplifying means,
pulsive component detecting means responsive to the output of said rectifying means for detecting at a second detecting level a pulsive component in said input signal, and
level ratio setting means operatively coupled to said detecting means and said pulsive component detecting means for controlling said first and second detecting levels of said detecting means and said pulsive component detecting means, respectively, for avoiding malfunction of said pulsive component detecting means by virtue of said continuous component in said input signal.

3 more elements

Dependencies are inferred from the claim text.