A device for detecting a tire pressure drop below a controlled value during drive of a vehicle comprises a magnetic member fixed to and rotating with the wheel rim and a switch element fixed to the wheel axle and responsive to an operative orientation of the magnetic field produced by the magnetic member which is carried by a pivotal shaft. A plunger responsive to the tire pressure drop locks the shaft and thereby the magnetic member in an inoperative position as long as the tire pressure is suf...

A lens device in an automatic focusing camera is operable to effect a first characterization of the light passing through one half of the lens device, and a second characterization of the light passing through the second half of the lens device. A sensor device includes first and second sensor arrays, each comprising a plurality of discrete light responsive elements. The sensor arrays are so arranged behind the lens device that the first sensor array receives only the light of the first characte...

A device for detecting the presence of liquid such as flood water, and for providing an audible alarm signal when such liquid is present. The device comprises a housing -- which is preferably of generally spherical shape and capable of floating in a stable upright position. In the housing is provided an electro-acoustic transducer provided with a metal diaphragm. At least two mutually spaced electrodes are supported on an exterior surface portion of the housing to be exposed to contact by liquid...

A multiwavelength radiation detector having the ability to integrate received radiation. The detector comprises a modified MOS field effect transistor wherein the gate takes the form of a cantilevered member formed from two layers of material of differing coefficients of expansion, one above the other. The free end of the cantilevered member extends over the space between the source and drain regions of the field effect transistor. As radiation impinges upon the cantilevered member, it will bend...

This disclosure describes apparatus and the method for continuously sampling either gaseous or liquid media such as atmosphere or water to detect the presence or absence of specific pathogenic micro-organisms. The system as described employs collection apparatus which entrains particles of microorganism size in continuous flowing stream of water. A suspension of fluorescently tagged antibodies is injected into the flowing stream and thereby maintained in contact for a sufficient period of time f...

A gas detecting device, particularly for detecting alcohol fumes, including a tubular body having a gas inlet aperture and a battery-actuated suction fan for aspirating the gas over a gas-sensitive semiconductor element, and indicator lamp means for emitting a signal in response to the semiconductor element sensing the presence of alcoholic fumes.

A focus detecting system includes a lens device for forming an image of an object on a predetermined plane through an optical path. A light gate positioned in the optical path is operable to alternately mask a portion of the optical path. A light responsive device is positioned at the predetermined plane to respond to the unmasked light from the lens device for producing electrical signals representative of the instaneous intensity distribution of the light received thereby. The intensity of the...

A liquid level detecting circuit has an amplifier with a regenerative feedback path and a degenerative feedback path. One of the paths contains a plurality of series connected probes which control whether or not the amplifier oscillates, depending on the liquid level.

A device for detecting the level of a liquid in a transparent tube including a radiation source to be placed facing a region of the periphery of the tube and a photocell to be placed facing a second zone of the tube periphery to receive radiation totally reflected from the internal face of the tube which has been wetted by a liquid, and which contains air rather than liquid. The device may be embodied in an automatic viscometer especially for coloured or opaque liquids.

A method and apparatus are provided for detecting changes in physical phenomena and for subsequently controlling response devices in accordance with such detected changes. A sensor responsive to changes in physical phenomena such as temperature, pressure, density and the like caused, for example, during the occurence and progress of a fire, is operable to sense such changes in physical phenomena during different stages of progress and to sequentially actuate and control the operation of various ...