Abstract: A deterioration determining device for an exhaust emission reduction device which is capable of improving the accuracy of determination of deterioration of a catalyst as a target, when another catalyst is disposed upstream of the target. The deterioration determining device for determining deterioration of a downstream one of two catalysts includes an ECU. After switching the air-fuel ratio from a learn value to a rich value, the ECU calculates an upstream oxygen storage capability using respective equivalent ratios detected by two LAF sensors, calculates a correction coefficient according to the value of the capability, calculates a basic value of a downstream oxygen storage capability using equivalent ratios detected by two LAF sensors, and multiples the basic value by the correction coefficient to calculate the downstream oxygen storage capability. When this is smaller than a predetermined value, the downstream catalyst is determined to be deteriorated.

Abstract: A deterioration determination device for a catalyst, which is capable of accurately determining deterioration of a catalyst without being influenced by the response delays of outputs from the upstream and downstream oxygen concentration parameter sensors. The deterioration determination device includes upstream and downstream LAF sensors for detecting respective upstream and downstream oxygen concentration parameters. After switching exhaust gases flowing through the former parameter sensor into the catalyst to a reduction atmosphere, an upstream oxygen concentration parameter detected for comparison when a predetermined time period elapses after it exceeds a predetermined value is compared with a downstream oxygen concentration parameter detected for comparison when the predetermined time period elapses after it exceeds the predetermined value. Based results of the comparison, deterioration of the catalyst is determined.

Abstract: An exhaust gas purifying apparatus for an internal combustion engine having a particulate filter provided in an exhaust system of the engine. Regeneration control is performed of burning particulates accumulated in the particulate filter. An oxygen concentration in exhaust gases flowing into the particulate filter is detected, and a flow rate of oxygen flowing into the particulate filter is calculated according to the detected oxygen concentration. An inflowing oxygen amount is calculated by integrating the oxygen flow rate when performing regeneration control. It is determined that an abnormality has occurred if the inflowing oxygen amount at a time when regeneration control ends is equal to or less than a predetermined amount.

Abstract: An exhaust gas purifying apparatus for an internal combustion engine, including a particulate filter provided in an exhaust passage of the engine; a pressure difference sensor for detecting a pressure difference between upstream and downstream side pressures of the particulate filter; an upstream side passage, which connects the pressure difference sensor and an upstream side with respect to the particulate filter of the exhaust passage; and a downstream side passage, which connects the pressure difference sensor and a downstream side with respect to the particulate filter of the exhaust passage. An exhaust gas flow rate is calculated according to an operating condition of the engine. A characteristic of change in the pressure difference, which is detected by the pressure difference detector and corresponds to a change in the exhaust gas flow rate, is detected. An abnormality of the downstream side passage is determined based on the characteristic of change in the pressure difference.

Abstract: An air-fuel ratio control system for an internal combustion engine having a catalyst provided in an exhaust system of the engine for purifying exhaust gases and a first oxygen concentration sensor disposed upstream of the catalyst is disclosed. The air-fuel ratio control system controls an air-fuel ratio of an air-fuel mixture supplied to the engine. A degree of response deterioration of the first oxygen concentration sensor is detected. A response delay of the first oxygen concentration sensor is compensated according to the detected degree of deterioration to calculate a compensated sensor output. The air-fuel ratio is controlled so that a detected air-fuel ratio calculated from the compensated sensor output coincides with a target air-fuel ratio. A frequency characteristic of the compensation is adjusted according to the detected degree of deterioration.

Abstract: Air-fuel ratio control system for an engine having a catalyst purifying exhaust gases, first oxygen sensor disposed upstream of the catalyst, and second oxygen sensor disposed downstream. Intake air flow rate is detected. An amount of oxygen flowing into the catalyst is calculated using oxygen concentration detected by the first sensor and the detected intake air flow rate. The air-fuel ratio is alternately controlled to lean and rich by comparison between the calculated oxygen amount and target values. A rich oxygen amount and a lean oxygen amount are calculated. A correction amount for correcting the first sensor output is calculated based on the rich oxygen amount, the lean oxygen amount, and an accumulated value of the detected intake air flow rate. The oxygen concentration corrected with the correction amount is used for calculating the inflowing oxygen amount, the rich operation oxygen amount, and the lean operation oxygen amount.

Abstract: An air-fuel ratio control system for an internal combustion engine having a catalyst provided in an exhaust system of the engine for purifying exhaust gases and a first oxygen concentration sensor disposed upstream of the catalyst is disclosed. The air-fuel ratio control system controls an air-fuel ratio of an air-fuel mixture supplied to the engine. A degree of response deterioration of the first oxygen concentration sensor is detected. A response delay of the first oxygen concentration sensor is compensated according to the detected degree of deterioration to calculate a compensated sensor output. The air-fuel ratio is controlled so that a detected air-fuel ratio calculated from the compensated sensor output coincides with a target air-fuel ratio. A frequency characteristic of the compensation is adjusted according to the detected degree of deterioration.

Abstract: A deterioration detecting method for a catalyst in an exhaust system of an internal combustion engine for purifying exhaust gases. The system includes a first oxygen concentration sensor and a second oxygen concentration sensor disposed, respectively, upstream and downstream of the catalyst. Intake air flow rate of the engine is detected. An amount of oxygen flowing into the catalyst is calculated according to an oxygen concentration detected by the first sensor and the detected intake air flow rate. An air-fuel ratio of an air-fuel mixture supplied to the engine is controlled by alternately switching between lean and rich with respect to the stoichiometric ratio according to a result of comparison between the calculated and target values of the inflowing oxygen amount. A deterioration degree of the catalyst is detected based on an output of the second sensor when performing the switching control of the air-fuel ratio.

Abstract: A deterioration detecting apparatus for a purifying catalyst in an exhaust system of an engine. A first oxygen concentration sensor is disposed upstream of the catalyst. A second oxygen concentration sensor is disposed downstream. An amount of oxygen flowing into the catalyst is calculated from the oxygen concentration detected by the first sensor and the detected intake air flow rate. A control command value of an air-fuel ratio is alternately switched between a first value corresponding to a lean air-fuel ratio and a second value corresponding to a rich air-fuel ratio according to a result of comparison between the calculated inflowing oxygen amount and target values. Excessive inflowing oxygen amounts are calculated. The target values are corrected with the excessive inflowing oxygen amount. A deterioration degree of the catalyst is detected based on an output of the second sensor when performing the switching of the control command value using the corrected target values.

Abstract: There is provided a melody and image synchronous generation system wherein melody and images matching thereto are synchronously generated at a communication terminal such as a mobile phone. With the communication terminal comprising a melody generator, an image generator, and event timing detection means for detecting event information inserted in melody information, when the event information inserted in the melody information is detected while melody is being generated, the image generator generates an image renewed based on image, information at timing of such a detection.

Abstract: A delay circuit having a delay element circuit composed of a plurality of series-connected first circuit elements being connected to a common power supply line and having a delay time varying correspondingly to a voltage of the common power supply line, the delay element circuit being adapted to receive an input signal and output an output signal obtained by delaying the input signal, and a PLL circuit including an oscillator circuit composed of a plurality of series-connected second circuit elements, which are equivalent to the first circuit elements, respectively, are connected to the common power supply line. The PLL circuit is adapted to oscillate the oscillator circuit at a predetermined frequency locked to a reference clock frequency by comparing a phase of the reference clock signal with a phase of an output frequency of the oscillator circuit and controlling the voltage of the power supply line according to a result of the comparison.

Abstract: A delay time control circuit comprises a delay circuit composed of 2n series-connected unit delay circuits each including a pair of series-connected, first and second inverters, where n is an integer equal to or more than 2, buffer circuits each connected to an output of each of the first and second inverters of the unit delay circuits of the delay circuit, 2n−1 first connection lines each connecting between outputs of adjacent ones of the buffer circuits connected to the second inverters and 2n−2 second connection lines each connecting between adjacent ones of the first connection lines. In response to an input signal input to the first inverter of first one of the unit delay circuit, an output signal delayed with respect to the input signal is obtained through one of the first connection lines and one of the second connection lines.

Abstract: A multi-channel D/A converter is formed with a plurality of converter units, each having one single input transistor and a plurality of output transistors which together form current mirrors. Mutually corresponding ones of these output transistors of different ones of the converter units, which are switched on and off together, are disposed adjacently and connected together to a trunk power supply line such that the parasitic resistances through the conductive lines connected to the output transistors are alike and the conversion characteristics of the individual converter units also become alike. One common input transistor may be shared by all of the converter units for further improving the conversion characteristic.

Abstract: A D/A converter has one single input transistor used in common with a plurality of output transistors to together form current mirrors, and a decoder serves to sequentially select the current mirrors in response to a digital input, causing to generate a corresponding analog output from currents from selected ones of the current mirrors. The commonly used input transistor is centrally located with respect to the current mirrors such that the difference between the maximum and minimum distances, or that between the maximum and minimum parasitic resistances, between the input transistor used in common and the output transistors is reduced and the conversion characteristic can be improved.

Abstract: An active terminator comprises a thermal shutdown circuit. When this circuit detects a predetermined high temperature, this information is supplied to a driver, and the active terminator stops operating. The signal from the thermal shutdown circuit is also supplied to an RS latch circuit that stores information to the effect that the thermal shutdown circuit has detected high temperature, and that the active terminator has stopped operation. A computer examines the contents of this RS latch circuit so that it can be determined that the terminator has stopped operating, and communication errors can therefore be prevented by, for example, reducing the data transfer rate accordingly.