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 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 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 multi-axis light beam type sensor with a simple fail-safe sensor system which stops when the sensor system is abnormal (logic value "0") is provided. The construction is such that scanning output signals for synchronously driving respective light emitting elements (LD) and light receiving elements (PD) positioned facing each other are generated using shift registers. A normal or abnormal condition of the scanning output signals is judged based on an output of the light transmission side shift register (5), using an addition operation in a scanning output signal checking circuit (9). Moreover, coincidence or non coincidence of last stage outputs of the respective shift registers of the light transmission and light reception sides, is determined by a coincidence detecting circuit (10).