Abstract: A rush current to an oxygen sensor is restricted to very small to secure the high reliability of oxygen sensor. A non-inverting input of an amplifier 30 is grounded. A resistor 31 is connected between an inverting input and an output of said amplifier 30. A limited electric current type oxygen sensor 34 is connected between said inverting input of said amplifier and a reference power supply 33.

Abstract: A main heater, auxiliary heater and guard heater arranged on an insulator substrate to absorb leakage current, thereby maintaining precise sensing temperature. The main heater is parallel with a bridge circuit containing the auxiliary heater, and the main and auxiliary heater s are typically adjacently arranged with a guard heater there between, electrically interconnected to maintain target temperature of the main heater, regardless of leakage current typically resultant from insulation substrate deterioration.

Abstract: An electric powered bicycle having a dip sensor or switch and/or a gradient sensor or switch. The bicycle has front and rear wheels each rotatably supported by a frame; a chain slung between the wheels and a chainset for transferring manual power to the wheels; an electric motor coupled to one of the wheels for driving the wheel directly; and a power supply capable of supplying electric power to the motor. The dip gradient sensors are associated with a pulse width modulation circuit.

Abstract: An electric powered bicycle having a dip sensor or switch and/or a gradient sensor or switch. The bicycle comprises front and rear wheels each rotatably supported by its frame; a chain slung between said wheels and a chain set for transferring manual power to said wheels; an electric motor coupled to one of said wheels for driving said wheel directly; and a power supply capable of supplying electric power to said motor. The dip or gradient sensors are associated with a pulse width modulation circuit.

Abstract: A DC motor control circuit for controlling a restraint torque of a DC motor which continues the rotation by triggering an external force. This control circuit is installed in a DC motor. In a DC motor control circuit comprising a drive transistor collector connected to a first brush of a DC motor, and a detection transistor collector connected to the base of said drive transistor and base connected to said first brush, a variable resistor is connected between the emitter of said detection transistor and a second brush of said DC motor and a capacitor connected between their one end and movable terminal of said variable resistor. The control circuit further comprises a drive current limiter for the drive transistor.

Abstract: Pressure detector circuits are disclosed in which a pressure sensor is connected to an amplifier having an output signal. A three state comparator compares the output signal with a first reference voltage to provide a comparison output which is fed back in a feedback path to another input of the amplifier through a low-pass filter. A first controllable circuit source connected in series with the first reference resistor are connected in the feedback path to detect an open or short circuit condition of the pressure sensor. Another controllable current source connected in series with a second reference resistor and a voltage divider are also provided in the feedback path which in combination with the first current source detect breaks and short circuit conditions of the pressure sensor. A switch connected is parallel to a high value resistor having a resistance higher than that of a low value resistor in the low-pass filter is also provided in the feedback path.

Abstract: A DC power supply for a DC motor is controlled by a drive transistor. An "ON" state of the drive transistor is maintained by a comparator which compares a terminal voltage at a point between the DC motor and the drive transistor with a reference voltage supplied from the power supply. A clock pulse is applied to the drive transistor to make it periodically turn off in order to detect an induced voltage depending upon the rotation rate of the DC motor. The drive transistor returns to turn off upon stopping the rotating DC motor by force.A regulator is provided between the power supply and the reference voltage. A restraint torque and a rotation rate control means are also provided.Alternatively, a pulsating power supply is provided instead of the DC power supply and the clock.

Abstract: An automatic window opening/closing system includes a motor for driving a window. In association with the window, a pressure responsive sensor (preferably, a pressure responsive sensor with a coaxial structure having uniform sensitivity to pressures in all directions) is provided. A detector circuit is coupled to the pressure responsive sensor and evaluates a rate of change of a pressure on the sensor, thereby detecting a squeezed object caught in a way of the window during an operation of the system. A motor control circuit is provided to control the motor in response to a squeezed object detection signal from the detector circuit in such a direction to release the object from the window. The motor control circuit detects an overload condition of the motor in accordance with a motor terminal voltage and deenergizes the motor to prevent the motor from generating heat. Therefore, this system achieves improved performance, high reliability and safety.

Abstract: An automatic window opening/closing system includes a motor for driving a window. In association with the window, a pressure responsive sensor (preferably, a pressure responsive sensor with a coaxial structure having uniform sensitivity to pressures in all directions) is provided. A detector circuit is coupled to the pressure responsive sensor and evaluates a rate of change of a pressure on the sensor, thereby detecting a squeezed object caught in a way of the window during an operation of the system. A motor control circuit is provided to control the motor in response to a squeezed object detection signal from the detector circuit in such a direction to release the object from the window. The motor control circuit detects an overload condition of the motor in accordance with a motor terminal voltage and deenergizes the motor to prevent the motor from generating heat. Therefore, this system achieves improved performance, high reliability and safety.

Abstract: A motor-powered opening/closing apparatus includes a circuit for detecting a constrained state of a motor as a power source of a window or a door and deenergizing the motor, and a circuit for detecting clamping of a foreign object between an edge of the window or the door and a fixed frame and stopping or reversing rotation of the motor. These circuits are independently arranged to detect clamping of the foreign object with high sensitivity while a closing force at the closed position can be kept large.

Abstract: An electric powered bicycle having a dip sensor or switch and/or a gradient sensor or switch. The bicycle has front and rear wheels each rotatably supported by a frame; a chain slung between the wheels and a chainset for transferring manual power to the wheels; an electric motor coupled to one of the wheels for driving the wheel directly; and a power supply capable of supplying electric power to the motor. The dip gradient sensors are associated with a pulse width modulation circuit.