Abstract:
In a condition monitor system for controlling a power supply in a vehicle, a charge/discharge circuit has a capacitor which is discharged in response to each of speed pulses of a speed sensor and periodic pulses of a microcomputer. When none of the pulses are generated due to abnormality, the capacitor is continuously charged without being discharged. When the charge voltage of the capacitor reaches a switching voltage, a relay is turned off to shut off the power supply to various parts in the vehicle. The charge/discharge circuit is commonly used to check generation of the speed pulses and the periodic pulses by setting the switching voltage in accordance with a possible maximum time interval of the speed pulses.
Abstract:
When a microcomputer is automatically reset due to uncontrollable process and recovers from reset, a cancel pulse signal is outputted from the microcomputer to a hold circuit to stop supply of a driving current to a relay. This pulse is generated, when a predetermined condition indicative of possibility of battery rundown lasts for a predetermined time. The predetermined condition includes that a hold set condition is detected based on a status signal inputted from the hold circuit; a card key is present in a key slot; a key verification inputted from an immobilizer ECU is not available; a vehicle speed is zero; and an engine revolution is zero.
Abstract:
A load operating means controls electricity supplied from a power source to a starter in an auxiliary system for starting an engine. An engine control means and an auxiliary electricity supply means turn the load operating means ON for supplying electricity from the power source to the starter in accordance with electricity supply from a power supply device when the engine is started. When voltage of the power supply device becomes less than a reset level, the engine control means resets electricity supply to the load operating means. When the engine control means starts the engine, the auxiliary electricity supply means supplies electricity to the load operating means at a timing simultaneously with or in advance of supplying electricity by the engine control means. When the engine control means resets the electricity supply, the auxiliary electricity supply means supplies electricity instead of the engine control means.
Abstract:
A load operating means controls electricity supplied from a power source to a starter in an auxiliary system for starting an engine. An engine control means and an auxiliary electricity supply means turn the load operating means ON for supplying electricity from the power source to the starter in accordance with electricity supply from a power supply device when the engine is started. When voltage of the power supply device becomes less than a reset level, the engine control means resets electricity supply to the load operating means. When the engine control means starts the engine, the auxiliary electricity supply means supplies electricity to the load operating means at a timing simultaneously with or in advance of supplying electricity by the engine control means. When the engine control means resets the electricity supply, the auxiliary electricity supply means supplies electricity instead of the engine control means.
Abstract:
In an on-board control system, a body ECU executes various control operations in response to the supply of power voltage from a battery. There is connected on the power line of the battery a voltage holding circuit which is formed of a capacitor so that the variation of battery voltage slows. A switch input circuit samples the on/off states of external switches periodically under control of a microcomputer. The microcomputer determines a fall of battery voltage, causing the switch input circuit to stop sampling of switch states. Stopping the circuit operation and thus reducing the battery load current slows the voltage fall at the occurrence of collision of vehicle, allowing adequate time to store collision data in a collision memory circuit.
Abstract:
An overcurrent protection circuit includes a load driver for driving a load, a controller for turning ON and OFF the load driver, a current sensor for measuring a load current flowing through the load, and an add/subtract circuit for performing both an addition operation and a subtraction operation on a previous calculation result or for performing only the subtraction operation on the previous calculation result so as to produce a present calculation result. The addition operation uses an added value depending on the presently measured current. The subtraction operation uses a subtracted value depending on the presently measured current. The controller turns OFF the load driver, when the present calculation result of the add/subtract circuit exceeds a predetermined determination value.
Abstract:
An overcurrent protection circuit includes a load driver for driving a load, a controller for turning ON and OFF the load driver, a current sensor for measuring a load current flowing through the load, and an add/subtract circuit for performing both an addition operation and a subtraction operation on a previous calculation result or for performing only the subtraction operation on the previous calculation result so as to produce a present calculation result. The addition operation uses an added value depending on the presently measured current. The subtraction operation uses a subtracted value depending on the presently measured current. The controller turns OFF the load driver, when the present calculation result of the add/subtract circuit exceeds a predetermined determination value.
Abstract:
A vehicular power supply circuit for supplying power to loads from a battery to drive the loads includes a power line and noise protection circuits. The power line is connected to the loads and systematically separated into multiple power lines based on characteristics of the loads to be connected. Each noise protection circuit is provided to a corresponding power line on the upstream side of the loads connected to the corresponding power line to serve as a common noise protection circuit for the loads connected to the corresponding power line.
Abstract:
The wiper driving apparatus module includes: a motor 12 for driving a wiper unit; a wiper ECU 11 for driving the motor 12; a deceleration mechanism (including gears). The two brush DC motor is employed and driven by a pulse width modulation (PWM) signal, in place of the conventional three brush motor wherein brushes are changed in accordance with a wiper operation speed. Therefore, the number of windings is only a number required for a high speed operation of the wiper unit. The high speed operation is implemented by 100% duty PWM signal, while the low speed operation is implemented by reducing the duty. The PWM signal duty is changed in response to a rainfall, windshield surface state and wind pressure which cause the wiping speed fluctuation.
Abstract:
A disconnection detecting apparatus for detecting disconnection of lamps includes a resistor, a differential amplifier, a microcomputer, and a charge pump circuit. The resistor is connected to detect current flowing in the lamps. The voltage that appears at the ends of the resistor is applied to the input terminals of the differential amplifier circuit. The microcomputer detects disconnection of the lamps by comparing the output voltage with a reference. The charge pump circuit increases a battery voltage to a boosted voltage. This boosted voltage is supplied to an operational amplifier in the differential amplifier circuit.