Abstract: The present invention relates to a fail-safe automatic sliding operation control apparatus for a press. The entrance and withdrawal behaviors of an operator's hand relative to danger zones (D, D.sub.N) on a bolster of the press are detected by an output generation configuration of two optical curtains. A signal for permitting a lowering operation of the slide is generated when the operator's hand is withdrawn from the danger zones (D, D.sub.N).

Abstract: A laser beam generated from a laser beam generating means 201 is reflected on a semiconductor mirror galvanometer 102. A region 105 to be inspected is scanned with the reflected laser beam 106. The laser beam 106 passing through the region 105 to be inspected is received by a light receiving device array 130. A pulse train included in an output signal produced from the light receiving device array 130 are monitored by a signal processing circuit 206. If an obstacle intrudes into the region 105 to be inspected and induces a pulse deficiency in the pulse train, the deficiency is detected by use of a pulse deficiency detecting circuit 204. A constitution mentioned above provides an optical barrier apparatus capable of reducing manufacturing costs without endangering a fail-safe property.

Abstract: The invention relates to a load drive circuit wherein an emergency shutdown switch for forcible interruption and a normal shutdown switch for normal current control are disposed in series in a load power supply circuit. An emergency shutdown switch (SW.sub.A) and a normal shutdown switch (SW.sub.B) are disposed in series in a load power supply circuit. The normal shutdown switch (SW.sub.B) is periodically driven off for a short time by means of a control signal (X) from a normal shutdown switch control circuit (30), and the fact that this is off is monitored by an output signal (AC) from a monitoring circuit (40). If the output signal (AC) is not generated for an off-delay time or more of an off-delay circuit (21), then a control signal (Z) for an emergency shutdown switch control circuit (20) is stopped thereby forcibly switching off the emergency shutdown switch (SW.sub.A).

Abstract: The present invention relates to an information generating apparatus for transmitting and receiving elastic waves through a transmission medium and for generating information which is necessary for controlling/monitoring associated elements of a control system.Elastic waves are transmitted and received by using the movement path (2, 111, 112, 211, 211') of a mobile unit (1, 151, 213) as a transmission medium. Based on a change in the level of a received elastic wave or on reception conditions, such as propagation time, of elastic waves, information on the timing of starting a sounding operation in a railroad crossing, information on the presence/absence of a mobile unit on a movement path, information on the presence/absence of rupture in a movement path or information for automatically controlling a train is generated.

Abstract: A rotation stopped detection sensor detects a rotation stopped condition of a rotatable body using a plurality of optical sensors. The detection sensor also includes a rotation disk having optical guide portions for guiding light beams from light emitting devices to respective light receiving devices, and light shut off portions for shutting off the light beams to the respective light receiving devices. The optical guide portions and the light shut off portions are disposed alternately on an outer peripheral portion of the rotation disk. The plurality of optical sensors are disposed such that when the disk is stopped, one of the optical sensors is always at a position corresponding to an optical guide portion. As a result, when the disk is stopped, there is always one output from the optical sensors which is at a high level. Hence the stopping of the disk can be advised using a direct output from the optical sensor.

Abstract: The present invention relates to a sensor for verifying that a motor has stopped rotating including rotation due to inertia.Respective signal input lines are connected to three power supply lines of a three phase AC motor. A high frequency signal current is supplied to one of the power supply lines, and the difference in the current flowing in the other two power supply lines is sampled from the signal input lines connected to the two power supply lines, and made an output from a sensor section. The sensor output is subjected to a threshold value operation in a signal processing circuit, and the resultant threshold operation output is output from an on-delay circuit as a motor rotation presence judgment output.

Abstract: The present invention relates to a moving body control apparatus wherein operating control flexibility and system maintainability are improved by carrying out moving body travel control by transfer of ultrasonic wave signals between moving bodies, without intervention of a ground apparatus. An ultrasonic wave transmission apparatus (1) is provided on one train (A), and an ultrasonic wave reception apparatus (10) and a signal processing circuit (13) are provided on another train (B). The timing of transmission and reception of ultrasonic wave signals is synchronized by timing signal generating circuits (2, 11) on the respective trains, and the ultrasonic wave signals are transmitted and received via a metal transmission medium (30). The reception side train (B) measures the transmission time for the ultrasonic wave signal by means of the signal processing circuit (13), and based on the measurement result generates information necessary for train travel control.

Abstract: A fail-safe signal transmitting apparatus including a power supply which does not let a transmission output signal generate an error that would allow a dangerous situation to arise even when a multiple failure has occurred in circuits constituting the signal transmitting apparatus. In particular, the present invention includes a source failure monitoring function and in order to monitor the power supply, a fail-safe window comparator and a fail-safe ON delay circuit are employed. An output signal constituted of the logical product of source monitoring signal and a signal to be transmitted and a carrier signal is used as a transmission signal.

Abstract: A rotation detecting means detects rotation of a mechanical movable portion and outputs a detection signal corresponding to the rotation rate of the mechanical movable portion. A rotation monitoring circuit, to which the detection signal from the rotation detecting means is provided, outputs a rotation-existing signal when the detection signal indicates that the mechanical movable portion is rotating. A rotation stop monitoring circuit, to which the detection signal from the rotation detecting means is provided, outputs a rotation-stop signal when the detection signal indicates a rotation rate lower than a predetermined rotation rate, and a movable portion control circuit uses at least either the rotation-existing signal or the rotation-stop signal and an external command signal for input signals to control the mechanical movable portion with logic of these signals.

Abstract: The invention relates to a drive control apparatus for a rotating machine having a movable part which is rotatably driven by a motor.The apparatus has a fail-safe construction which gives an output of logic value "1" when the movable part is stopped, wherein, to enable supply of motor current to start a motor (2) at the motor start-up time under a condition of the movable part stopped, motor drive permission is granted by a logical product output which is obtained by a logical product operation of a start signal generated by switching a start switch on, and a logical sum output obtained by a logical sum operation of an output of a current sensor (3) generating an output of logic value "1" when the motor current does not flow and an output of a rotation sensor (4) generating an output of logic value "1" when the movable part is rotating.

Abstract: The invention relates to an electromagnetic relay drive circuit which generates an electromagnetic relay excitation signal after first verifying that the electromagnetic relay make contact points are off. A forced-operation electromagnetic relay with make contact points and break contact points having complementary relationship with each other is used, and when the break contact points are on, that is to say the make contact points are off, a trigger input signal of logic value "1" with a predetermined level range is applied to a trigger input terminal of a self hold circuit. When an input signal IN of logic value "1" within a predetermined level range is applied to a reset terminal while the trigger input signal is being applied, the relay is excited and the make contact points switch on.

Abstract: The invention relates to a highly reliable mat sensor which can also detect temporary faults in a sensor portion. Two sensor portions are provided, and agreement or disagreement of an ON/OFF condition of the output from the two sensor portions is detected, and when the output conditions of the two sensor portions are in agreement, then a normal judgment signal for both sensor portions is generated. When the normal judgment signal is generated and the two sensor portions are OFF, an operation permit signal for a movable portion of a machine is generated. Moreover, the presence or absence of a body is detected from a change in value of the electrostatic capacity of one sensor portion. In this way, a temporary poor contact attributable to deterioration of the sensor portion can also be detected, and the movable portion of the machine can be stopped.

Abstract: A detection means 1 detects changes in impedance generated at a coil TC caused in response to indentations Py1 and Py2 and projections provided at the surface of a movable portion Rot to generate a detection signal thereof. A speed judgement circuit 2, to which the detection signal from the detection means is provided, continuously generates a high level output signal A2i when the detection signal e change interval becomes greater than a specific length of time. A level detection circuit 3, to which the detection signal e is provided, generates a high level output signal A1i when the detection signal e is at or above a specific level. An AND circuit 4, to which the output signal A2i from the speed judgement circuit 2 and the output signal A2i from the level detection circuit 3 are provided, generates an output signal Z resulting from AND calculation of the two output signals A1i and A2i.

Abstract: A detector 1, with its object of detection having operation characteristics that include a shift from a first state to a second state, outputs a signal e1 that corresponds to the operation characteristics of the object of detection. A first state detection circuit 2 generates a first output signal SA corresponding to the first state based upon the signal e1 provided by the detector 1. A second state detection circuit 3 generates a second output signal SB corresponding to the second state based upon the signal provided by the detector 1. The second output signal SB is generated only when the object of detection shifts from the first state to the second state in a normal manner while the first output signal SA is being generated. A state judgement circuit 4 generates a state judgement output signal Z on condition that there has been a period of time during which the first output signal SA and the second output signal SB have been both at high.

Abstract: A leakage and earthing wire disconnection detection apparatus monitors for earthing wire disconnection and leakage of an electrical or electronic device during operation of the device. Two earthing wires are independently provided for the electrical or electronic device. The ends of the earthing wires on the electrical or electronic device side are electrically connected together, while earth-side ends are connected independently to earth. A single closed loop is made up of the two earthing wires, the electrical or electronic device, and earth. A detection circuit determines that the earthing wires are normal when the closed loop is closed, and abnormal when the closed loop is open. In addition, the apparatus performs leakage detection of a motor, or the like, based on a current level flowing in the earthing wires.

Abstract: A bridge circuit monitoring apparatus which can accurately detect a fault in a bridge circuit of a sensor circuit even when multiple faults occur. Changes in the imbalance output signal of a bridge circuit (11) are monitored with a first window comparator (WC1), while changes in the bridge circuit (11) power source current, which does not require amplifying, are monitored with a second window comparator (WC2). At the time of an output of logic value "1" indicating that the monitoring outputs are both normal, an output of logic value "1" indicating that the bridge circuit (11) is normal is generated from an AND gate (13).

Abstract: The invention relates to a motor stopped verification apparatus for verifying if a motor has stopped rotating, and in particular to rotation sensor technology for sampling rotation signals from a motor. With a first aspect of the invention, a high frequency current signal is supplied to the winding of a tachometer generator incorporated in a motor. This high frequency signal is modulated by an output signal from the tachometer generator, and the modulated signal made a motor rotation detection output from a rotation sensor. With a second aspect of the invention, a transducer coil is utilized as a part of an oscillator, and the motor rotation is converted to a change in the oscillation frequency of the oscillator and then sampled. With a third aspect of the invention, the motor rotation is converted by means of a resonance circuit incorporating the transducer coil, into a change in terminal voltage of the resonance circuit and then sampled.

Abstract: A movable section of a machine is enclosed by a fence and a door. A locking device provided on the door is controlled by a movable section control circuit. In the movable section control circuit, an operating switch outputs either a movable section ON signal or a movable section OFF signal. A door switch outputs an ON signal representing that the door is open. A switch means constitutes a self-holding circuit which uses an AND signal constituted of the movable section OFF signal from the operating switch and a rotation stop signal as a reset input signal and an OR signal constituted of an ON signal from the door switch and a rotation-presence signal as trigger signal to provide the locking device with a control signal. When a sensor fails, the locking devive is not unlocked even if the operating switch for driving the movable section is closed.

Abstract: A residual pressure sensor for verifying that a residual pressure is zero, and to a monitoring apparatus for monitoring for faults in the residual pressure sensor. In order to detect that a residual pressure has completely gone, the residual pressure sensor detects change conditions in the output therefrom, and an output for no residual pressure is not generated while there are changes. Moreover, an electrical power supply condition to a drive solenoid (21) of a solenoid valve for opening/closing a pressure supply line, is monitored using a fail-safe current sensor (21) which outputs a logic value "0" when the presence of a current is detected, and which outputs a logic value "1" when the presence of a current is not detected. Fault monitoring of the residual pressure sensor is then carried out based on the monitoring output conditions of the current sensor and the output conditions of the residual pressure sensor.

Abstract: This invention relates to a load driving circuit having a fail-safe breaking mechanism for breaking a primary power source when a failure occurs. This invention also relates to a load driving circuit capable of saving electricity in driving an inductive load and reducing a delay in stopping the load. The breaking mechanism for braking the primary power source has no contact. The load driving circuit includes a power supply circuit involving a semiconductor switching element that turns ON and OFF the supply of power to the load. There is arranged a detector for detecting a failure in the semiconductor switching element. When detecting a failure, the detector provides an output signal to activate the breaking mechanism. To drive the inductive load, the power supply circuit may have two power supply sources. In response to a load driving instruction signal, the two power supply sources together apply a high voltage to the load.