Abstract:
An alarm device such that whether the alarm device is in a normal state capable of raising an alarm can be always confirmed. When a high-level judgement signal (W) representing safety in inputted, a V-F converter (11) supplies an inaudible signal having an inaudible frequency to a loudspeaker (13) so as to cause the loudspeaker (13) to produce an alarm having an inaudible frequency; and, when a low-level (zero-level) judgement signal representing danger is inputted, the converter (11) supplies a signal having an audible frequency to the loudspeaker (13) so as to cause the loudspeaker (13) to produce an alarm having an audible frequency. While an output current having an inaudible or audible frequency is supplied to the loudspeaker (13), whether or not the alarm device is normal is confirmed by extracting the output current by means of the current transformer (21) of a monitoring circuit (20) and generating a DC output signal (SN) by amplifying and rectifying the output current.
Abstract:
A residual pressure sensor for ascertaining a zero residual pressure, and an apparatus for monitoring the sensor for failure thereof. In order to detect a residual pressure reduced to zero, the condition of variation of an output from a residual pressure sensor is detected. This residual pressure sensor is not allowed to generate an output representative of zero residual pressure while the first-mentioned output varies. The energizing condition of a driving solenoid (21) for a solenoid valve which is adapted to open and close a pressure supply passage is monitored by using a current sensor (21) of a fail-safe structure adapted to detect the presence of a current and output a logical value 0, and detect the absence of a current and output a logical value 1, and the residual sensor is monitored for failure based on the monitor output condition of the current sensor and the output condition of the residual pressure sensor.
Abstract:
The present invention relates to a small-sized thin galvanomirror for detecting the displacement angle of a mirror, which is produced by a semiconductor process. By using a semiconductor process, a movable plate (5) and a torsion bar (6) for supporting this movable plate (5) are integrally formed on a silicon substrate (2), and a planar coil (7) and a total reflection mirror (8) are formed on the upper surface of the movable plate (5). Permanent magnets (10A, 10B) and (11A, 11B) for generating magnetic fields are fixedly disposed on the planar coil (7) to thereby control the amount and direction of current to be conducted to the planar coil (7) so as to variably control the swinging angle of the movable plate (5) through the balance between a magnetic force generated and a torsional force by the torsion bar (6). Furthermore, detecting coils (12A, 12B) are provided below the movable plate (5) to thereby cause a detection current to flow to the planar coil (7) by superposing it on a driving current, whereby the detection of a displacement angle of the mirror is performed through the relative inductance variation between the planar coil (7) and the detection coils (12A, 12B) based on this detection current.
Abstract:
This circuit detects ON failure of a switching element for controlling the power supply to a load, and shuts down the load current reliably. The circuit comprises a monitoring sensor which generates an output when energy is externally supplied to the switching element of a switching circuit the switching element is off, and the reception level of the energy at the sensor is accordingly high; and conversely does not generate any output when the switching element is on and the reception level is accordingly low. By utilizing an OR operation circuit and a self-holding circuit, the output from this monitoring sensor, and the load driving signal for driving the switching element are logically processed. The relay contacts are prevented from hunting and following up the load driving signals in case of ON failure of the switching element.
Abstract:
A device for securing the safety of a worker, wherein a mechanically movable section is surrounded by a safety fence, a door lock means unlocked when a built-in solenoid is supplied with electric current from the outside and excited is provided to a door formed in the safety fence, and a door switch is unlocked when the mechanically movable section is stopped. Further, a movable section monitoring sensor is provided for monitoring whether the mechanically movable section is stopped or not, and, when the mechanically movable section is stopped, the movable section monitoring sensor produces an output signal of a logical value (1) corresponding to a high energetic state without performing NOT operation and energizes the solenoid of the lock door means in response to this output signal. With this arrangement, only when the mechanically movable section is stopped, the door lock means is unlocked. Furthermore, in case when the sensor is in trouble, the solenoid is not energized, whereby the door lock means is not unlocked, so that the safety of the worker can be reliably secured.
Abstract:
A fail-safe current sensor and a rotation sensor of a motor using the current sensor. A first transformer (T1) for applying a high frequency signal, a second transformer (T2) for detecting the high frequency signal and a motor (1) constitute a closed circuit. The first and/or second transformer has a saturable magnetic core (C1, C2). The transformer equipped with the saturable magnetic core gets into saturation by a current flowing during the rotation of the motor, the high frequency signal from a signal generator (11) is not transmitted, and the output of a receiver (12) takes a logic value 0 for a warning. The transformer does not get into saturation when the motor is at halt, and the output of the receiver takes the logic value 1 and represents safety. The output of the receiver assumes the logic value 0 for a warning when disconnection occurs in a motor power feed line.
Abstract:
The present invention uses a sensor (10n SIMILAR 15n, 16) which transmits detection data of an object (M) by the decrease of an output signal energy, as a sensor for detecting people, and a sensor which transmits the detection data of the object (M) by the increase of the output signal energy, as a sensor (21 SIMILAR 26) for detecting a work. Driving of a mechanical movable portion is permitted only when the logical sum of the outputs from both sensors is a logical value 1 corresponding to the high energy state. In this way, the present invention provides a safety apparatus which has a high fail-safe function and can reliably secure safety of operators.
Abstract:
This invention relates to an apparatus which can supervise centrally and detect disconnection when one or more lamps among a plurality of lamps connected in series such as guide lamps in the runway of an airfield are disconnected. A core (12) is disposed on a power line (P1) of each lamp (L1 SIMILAR Ln), the power line (P1) is wound on the core (12) as a first winding (N1), a second winding (N2) for extracting the power of the power line (P1) is wound on the core (12), an oscillator (13) is disposed which uses the output voltage of the second winding (N2) as the power supply to generate a frequency corresponding to each lamp (L1 SIMILAR Ln), and the output signal from this oscillator (13) is returned to the power line (P1) through a third winding (N3). Accordingly, a signal consisting of a frequency which represents each lamp flows through a lamp turn-on circuit and any disconnected lamp or lamps can be detected by checking this signal.