Abstract: A superregenerative receiver includes a quenching oscillator for converting a received signal into a low frequency signal. The quenching oscillator comprises a transistor, a positive feedback circuit and an RC time constant circuit. A circuit is provided for modifying oscillation conditions including the base voltage of the transistor, a power supply voltage and the RC time constant of the RC circuit. In response to the output of the quenching oscillator whose oscillation condition or conditions have been modified, the quenching oscillator is placed into its optimum operating state in order that the receiver assumes substantially the maximum sensitivity.

Abstract: An intrusion warning system for indicating the presence of an intruder to a given area comprises a single antenna line encircling the area insulated from the ground, a high frequency oscillator (e.g. of 1 kHz to 10 kHz) for feeding a high frequency signal to the antenna, a coupling impedance, for example, a capacitor, connected between the output terminal of the oscillator and the antenna, and a signal processing part which produces an alarm when detecting a voltage change over a predetermined level of the antenna induced by a proximation of the intruder.

Abstract: Means for mounting a member functioning with a directivity to a mounting station of an associated device or the like. A housing for the member with its functional end surface exposed to the exterior is tapered at the periphery toward the other end to be, for example, hemispherical and rotatably born at diametrally opposed positions adjacent the functional end surface by both ends of a semiarcuate bearing means, the mounting station has a hole including peripherally opposing grooves of a size and shape capable of slidably engaging with the tapered periphery of the housing and receiving semiarcuate body of the bearing means, the housing is inserted in the hole on said the other end side, and the semiarcuate body of the bearing means in the inserted position of the member engages slidably with a resilient means acting to resiliently urge the tapered periphery of the housing against peripheral edge of the hole.

Abstract: A moving object detecting device employing a pair of Doppler signals as a pair of vector signals of respective received-wave signals representing momentary reflected waves from a moving object. These vector signals are processed to obtain signals denoting in which ones of predetermined zones for the vector rotation depending on the movements of the object the vector is momentarily present, and shifting states of such zone signals through the zones are traced to sequentially determine the direction and period of the vector rotation and to actuate an alarm or the like when the rotation is in a fixed direction.

Abstract: An echo-type switch using ultrasonic wave for detecting any object present in a predetermined area with reliable operation irrespective of environmental variations or foreign waves. After the wave is once radiated, the detection is suspended for a fixed time period T.sub.1 and presence or absence of reflected wave received is confirmed during another period T.sub.2. If reflected wave is received in the period T.sub.2, this period is again set for further confirming if the received wave continues and, until absence of the received wave is confirmed after several times of the waves received during the period T.sub.2, next ultrasonic wave is not radiated. Only in case the reflected wave received continues for more than two of the periods, the presence of the object to be detected in the area is indicated.

Abstract: This invention provides an ultrasonic wave watching device for detecting a moving object wherein an ultrasonic wave signal generated by an oscillator is transmitted from a transmitter, reflected signals from a stationary object and moving object are received by a receiver and the variation with time of the phase difference between these received signals and the transmitted signal is detected to determine the presence and moving direction of the moving object.

Abstract: An ultrasonic wave horn adaptable to any desired radiation pattern varying in length-to-breadth ratio of intended detecting area. The horn comprises at least a horn body having gradually expanding caliber from a constricted throat to an expanded opening which is of a flat shape with an unequal length-to-breadth ratio, and an ultrasonic wave generating source of which wave emitting side is disposed adjacent the constricted throat of the horn body, wherein the constricted throat of the horn body is also of a flat shape having an unequal length-to-breadth ratio and the respective major axes of the flat-shaped constricted throat and expanded opening of the horn body are in a relation of intersecting each other at right angles.