Hitachi, Ltd.

Koji Yamauchi

Shigeru Matsuoka

Hiroyuki Tadokoro

Seiji Yonekura

Mitsuo Suzuki

Takeshi Tokunaga

Shigeyoshi Kawano

Masahiro Ueno

Shoichi Ito

Masami Joraku

A control system for an illumination lamp installed in a building equipped with a door operation control apparatus. The system comprises a door opening and closing instructor, a control circuit responsive to an instruction signal from the instructor to produce a door control signal and a lamp control signal, a door driver responsive to the door control signal to drive the opening and closing of a door, an illumination lamp for illumination of the interior of the building, a detector for detecting the movement of a human body and producing an electric signal representative of the movement, and a circuit which is responsive to the lamp control signal and the electric signal to turn on the illumination lamp and keeps the illumination lamp turned on for a predetermined time extending from the termination of the lamp control signal and the electric signal.

Control system for illumination lamp installed in building equipped with

Disclosed is an exposure amount control device for a copying machine comprising an exposure amount control circuit for controlling an exposure amount by controlling light of the exposure lamp for illuminating an original document to be copied and a digital light control signal generator for supplying a digital light control signal of a variable duty factor to the exposure amount control circuit. The digital light control signal generator includes a light intensity increase/decrease setting circuit and an oscillator for generating an oscillation output of a variable oscillation period in accordance with a light intensity signal from the light intensity increase/decrease setting circuit. The oscillation output of the oscillator is converted to an on-off light signal, which is supplied to the exposure amount control circuit as the digital light control signal. Thus, the digital light control signal generator is perfectly electrically isolated from a primary power supply circuit of the exposure amount control circuit and a highly safe exposure amount control device with a stable control ability due to an on-off light signal is provided.

Exposure amount control device for a copying machine

A temperature control device for a fixing heat source of a copying machine includes circuits for supplying power to the fixing heat source in synchronism with the zero-cross point of an a.c. signal applied from an a.c. power source. The device functions to supply the full-wave current to the heat source until a first predetermined temperature is sensed by a temperature sensor, to supply the half-wave current to the heat source until a second predetermined temperature is then sensed, and to change the duty factor of the half-wave current after attainment of the second predetermined temperature, thereby maintaining constant the temperature of the heat source with high accuracy.

Temperature control device for fixing heat source of copying machine

A motor driving a garage door is controlled by a controller, and the rotation of the motor in the normal and reverse directions is normally controlled in response to an actuating signal applied to the controller from a main push button switch. In a specific-mode in which an actuating signal is applied to the controller from an emergency push button switch, a mat switch or a fire sensor, the latter signal has priority over the former signal, and the motor is driven to move the garage door to its full-open position.

Door operation control apparatus

A motor for driving a garage door is controlled by a control unit, which counts the time required for the garage door to move between an upper limit switch and a lower limit switch. The control unit sets a comparison reference time on the basis of the time thus counted, and controls the motor in such a manner that the motor driving does not continue for a period of time longer than the comparison reference time.

An automatic door operation control apparatus is disclosed which comprises a door operating device a driving device for opening and closing the door, a condition detector for detecting a condition under which the movement of the door by the driving device is required to be discontinued, and a main control device for issuing a driving command to the driving device to actuate the same as required in response to a condition detection signal from the condition detector. The apparatus further comprises an auxiliary control device for stopping the operation of the driving device in the event that the main control device fails to issue a command to the driving device to stop the door movement within a predetermined length of time in response to the condition detection signal from the condition detector.

Automatic door control apparatus

A motor for operating the door is controlled for forward and reverse rotations and stoppage by a control circuit responsive to an operation command signal, an upper-lower limit signal, an obstruction detection signal and a maximum drive time over signal, thus controlling the door stepwise for opening, stoppage, closing, stoppage and opening in that order. Upon generation of an obstruction detection signal or a maximum drive time over signal during the closing operation, the control circuit controls the motor in a manner to open the door for a certain period of time, and subsequently upon application of an operation command signal, the control circuit is set in a manner to open the door again.

A main control circuit for controlling a door open-close drive motor and a lamp illuminating the interior of a garage is disposed in a body of a door operation control apparatus, and an interface circuit for applying control command signals to the main control circuit is connected by two signal conductors to a control box mounted on the wall of the garage. Signal voltages of a plurality of levels can be generated from the control box to be transmitted to the interface circuit by way of the two signal conductors, and the interface circuit discriminates the level of one of the signal voltage transmitted by way of the two signal conductors to apply a control command signal for controlling a controlled object corresponding to the discriminated voltage level.

A moving apparatus for a load lifts the load by the torque of a motor, and balances and holds the same with the aid of a mechanical brake when the apparatus stops. A timing device is incorporated in brake control so that when the apparatus stops in response to a signal indicating that a zero speed is designated, the mechanical brake is operated with a time lag after the receipt of the signal and, as soon as the brake is applied, the power supply to the motor is cut off. This arrangement remarkably reduces the impact of stopping upon the mechanical brake and drive, lessens the wear of the brake, permits reduction in size of the components and extends the service life of the components, thus providing an apparatus which saves power in comparison with conventional equipment.

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Hitachi, Japan

Koji Yamauchi