Nippondenso Co., Ltd.

Toyota Jidosha Kabushiki Kaisha

Akira Ikuma

Yoshikazu Mizuno

Takeshi Ochiai

Yutaka Ninoyu

Motoyoshi Suzuki

Katsumi Gonda

Apparatus for effecting the impedance discrimination for use in an automobile comprises a plurality of switches (11-14) mounted on a steering wheel, and a plurality of first impedance elements (15-17) for providing a different impedance in response to the operation of each switch. A second impedance element (131) is coupled through a common slip-ring connection (8, 9) to the first impedance elements for feeding a current from a battery (1) to the first impedance elements (15-17) to generate a potential corresponding to the operation of one of the switches. A transistor (133) provides a horn activating signal when the potential reaches a predetermined value. A resistance network (141-144; 141-142, 150-154) derives a first value corresponding to the first potential and a second value corresponding to the battery potential. A potential discriminator (110) derives a relative value from the first and second values and detects which one of the switches is operated as a function of the relative value to generate a control signal associated with the operated switch.

Impedance discriminator responsive to operation of switches mounted on a

An automotive vehicle speed control system, in which steady speed drive control is effected. When a vehicle steady speed is increased to the next steady speed, a target signal for the next steady speed drive is increased by a predetermined value immediately after generation of a steady speed incremental signal, followed by increasing the target signal by amounts per time thereby to increase the steady speed. g

Automotive vehicle speed control system

An automatic speed control system comprises a bistable device, a coincidence gate and a monitor circuit which monitors the speed control element of an engine and applies a first input signal to the coincidence gate if malfunction occurs in the speed control element. The coincidence gate provides a reset signal to the bistable device when it simultaneously receives a second input signal from a microprocessor. The microprocessor verifies the operating conditions of the bistable device before the system is switched to automatic mode and sets the bistable device into a condition for receiving the reset signal from the coincidence gate. During automatic control mode, the microprocessor constantly checks the bistable device if it turns to the reset condition while controlling the speed control element. Whenever the microprocessor detects a reset condition in the bistable device, it enables the speed control element to allow the engine to be controlled on manual mode. A malfunction of the microprocessor will also cause the coincidence gate to provide a reset signal to the bistable device.

Fail-safe speed control system for motor vehicles

A control circuit system for an automobile comprises a plurality of command switches (including an electric horn switch) all provided on a steering wheel. A control circuit is provided to generate a control signal in response to each command signal from the switches, and a signal coupling element is provided to connect the switches and the control circuit through a single signal line conventionally used for the electric horn switch. Operation of the automobile horn is enabled through a normally-closed relay even when a power switch connecting the automobile battery and the control circuit is open, thereby eliminating continuous drain on the automobile battery by a dormant but powered control circuit.

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Kariya, Japan

Akira Ikuma