Abstract: A device for indicating information on the return route for an automotive vehicle includes a memory and control portion for successively storing the detected direction signals and the detected distance signals on the route to a destination and successively generating indication signals to the extent of a predetermined distance in the forward direction on the return route on the basis of the stored detected direction signals and the distance signals. The device also includes a circuit for correcting the difference between the distance of the vehicle travel on the route to the destination and the return route, so that the correct indication of information of the return route is displayed on a display device such as a CRT.

Abstract: A device and method for detecting the running direction of an automotive vehicle includes terrestrial magnetic field direction detection, vehicle steering angle detection, and response to the signals of these detectors for producing the vehicle running direction signal. In a computer, or equivalent circuitry, occurrence of abnormalities of the terrestrial magnetic field is decided when the relationship between the change in the vehicle running direction and the change in the steering angle does not satisfy a predetermined requirement.

Abstract: A heading detecting apparatus of the type which is installed in a roof of a vehicle including a magnetic member (a steel body) capable of having a remanence and includes a heading sensor positioned near the magnetic member, whereby the apparatus detects the terrestrial magnetism and thereby detects the forward heading of the moving objects the apparatus includes a permeability member positioned between the magnetic member and the heading sensor so as to reduce the effect of the remanence of the magnetic member on the detection of the terrestrial magnetism by the heading sensor.

Abstract: A heading detecting apparatus is attached to a moving object and includes a geomagnetic field sensor for detecting the direction of the earth's magnetic field in terms of orthogonal first and second signals and a computing circuit responsive to orthogonal first and second electric signals from the geomagnetic field sensor. In the computing circuit, when any one of the orthogonal first and second electric signals from the geomagnetic field sensor is a predetermined value, the value of the other electric signal is detected so that in accordance with the detected value an offset value is computed and stored, and the electric signals from the geomagnetic field sensor is corrected in accordance with the offset values.

Abstract: A magnetic field measuring apparatus including a magnetic sensor having an excitation winding and orthogonal first and second output windings for generating a first and a second output signal indicative of the orthogonal components of an external magnetic field, adjusting circuits for adjusting the amplitude and frequency of the sensor output signals, circuits responsive to common timing signals whereby the outputs of the adjusting circuit are subjected to sample-and-hold operation and A/D conversion and the resulting converted outputs are counted to generate count outputs, and a first and a second display unit for simultaneously displaying the count outputs.

Abstract: A vehicle's heading indicating apparatus includes a direction-finding sensor having a pair of external field sensing windings wound perpendicular to each other, a sensor exciting oscillator circuit, a signal sampling timing circuit, sample-and-hold circuits, comparators, a logic circuit and an indicator circuit. The output of each of the sensor windings is divided into predetermined (N+1) signal levels such that the heading or direction of travel of a vehicle is detected and indicated in accordance with the combination of each two signal levels sensing the heading, and also large disturbance of the earth's magnetic field is sensed such that the just preceding direction of travel obtained is indicated when the earth's magnetic field is excessively low or high.

Abstract: An apparatus for generating a parallel magnetic field by passing current through a coil cylindrically wound and shielded against the external magnetic fields by a magnetically shielded housing incorporating a fine meshed material such as a high magnetic permeability amorphous alloy. Inside the housing, there are provided a non-magnetic bobbin, on which the coil is wound, and a power source for providing current to the coil to produce a parallel magnetic field of an intensity corresponding to that of the current to be generated within the bobbin.

Abstract: An automobile running position indicator apparatus which comprises a device for generating a unit coverage distance signal each time the automobile has covered a unit distance, a device for generating a direction signal representing the automobile running direction at each time and a device for generating set signals representing the distance and direction from the starting point to the destination. A vectorical length from the starting point to the destination is operated from the set signals. The distance covered by the automobile is accumulated for each direction from the distance signal and the direction signal thereby to calculate a vectorial value length from the starting point to the present position. These vectorial values are used to determine a vectorial length from the present position to the destination, and the resulting vectorial direction and distance are displayed in the same display section.

Abstract: In a direction indicator including a direction sensor having an excitation coil wound on a core and two output coils wound thereon to cross at the right angles with each other, a direct current of given amount is supplied to the two output coils and a direct current magnetic field is produced so that the maximum values of the output signals is made equal by adjusting the gain of the output signals.

Abstract: A demagnetizer for removing residual magnetism in vehicles includes a single coil which is adapted to surround a portion or the whole of the body of a vehicle. A direct current and alternating current are supplied to the single coil simultaneously to produce a d.c. magnetic field and an a.c. magnetic field. The direction and magnitude of the d.c. magnetic field are so arranged, that the d.c. magnetic field cancels the external magnetic field. The magnitude of the a.c. magnetic field is varied within a predetermined range periodically to remove the residual magnetism.

Abstract: A direction finding system of the type finding a present direction on 4N direction divisions defined by 2N boundary levels for automotive vehicles, said system comprising a magnetic sensor circuit for generating a pair of electric signals indicating two perpendicular components of the earth's magnetic field, a logic circuit for signal-converting the electric signals, discriminating and latching to generate direction indicating 2N binary signals with reference to predetermined 2N boundary indicating levels, a sorting circuit for sorting the binary signals to generate one of 4N direction signals and a display device for displaying a corresponding direction.

Abstract: A demagnetizing apparatus for removing residual magnetism in the body of an automobile which is equipped with a magnetic bearing indicator. A first and a second coil are wound around a substantially flat frame of a non-magnetic material to produce respectively a fixed d.c. magnetic field and a controllable a.c. magnetic field in orthogonal directions with each other and along flat surfaces of the substantially flat frame. The substantially flat frame with coils is positioned adjacent to but spaced from a body portion such as a roof, door or floor of the automobile, so that the d.c. magnetic field produced by the first coil cancel the external magnetic field caused by the terrestrial magnetism. The a.c. magnetic field is controlled to be intensified and weakened alternately thereby to remove the residual magnetism of the body portion without being influenced by the external magnetic field.

Abstract: An apparatus for displaying the driving direction and distance coverage of a motor vehicle, wherein a unit distance coverage signal is generated each time the motor vehicle covers a unit distance, a direction signal indicating the present driving direction of the motor vehicle is generated, and the distance and the direction from a starting point to a destination point can be set and the resulting setting signals are generated. The distance coverage for each driving direction of the motor vehicle is accumulated on the basis of the unit distance coverage signals and the direction signals, and from the accumulated values the vector from the starting point to the present position is calculated. The calculated vector and the vector from the starting point to the destination point which is obtained from the setting signals are used to calculate the vector from the present position to the destination.

Abstract: An exhaust gas purifying system for internal combustion engines includes a three-way catalyst disposed in the exhaust system of the engine, and secondary air is supplied to the exhaust system through an air control valve under the control of an air-fuel ratio control circuit. The air-fuel ratio control circuit produces a control signal which increases or decreases stepwisely at every reception of a clock signal depending on whether the air-fuel ratio in the exhaust system is above or below a stoichiometric air-fuel ratio. The air control valve is of the proportional electromagnetic type and controls the secondary air passing therethrough in proportion to the control signal.

Abstract: A method for demagnetizing an automobile is disclosed in which the terrestrial magnetism is detected by a direction-detecting sensor and the running direction of the automobile is indicated in response to a signal produced from the direction-detecting sensor. The distortion of the magnetic field caused by the permanent magnetism of the magnetic materials of the whole body of the automobile is erased by placing the automobile in an AC magnetic field which gradually increases from zero to a predetermined intensity and then gradually decreases to zero, and thereafter the direction-detecting sensor is mounted at the magnetic center of the automobile.

Abstract: A linear solenoid valve actuation device comprises a step wave generating circuit comprising a converting circuit whereby the desired amount of control is computed at a predetermined period of clocks to hold or store the computed value until the next computation and generate a step wave voltage having a value corresponding to the computed value, and a current amplifier circuit for supplying to a linear solenoid valve a current having a value corresponding to the output voltage of the step wave generating circuit, thereby actuating the linear solenoid valve with a step waveform current.