Abstract: The object of the invention is a system and method for identifying and communicating with a plurality of transponders which are at the same time in the same interrogation field. The system is based on an interrogator which sends interrogation bursts in a periodical manner, and transponders which send the response back with a random delay related to the end-of-burst event. The system is primarily suitable for passive (no additional power supply) transponders, but can also be used for active transponders.

Abstract: A position detector includes an outer tube of having a magnetostrictive wire disposed therein. An electric circuit is mounted completely within the outer tube and is electrically connected to a pickup coupled to the magnetostrictive wire. A multi-pin connector is mounted at one end of the outer tube for coupling conductors extending from the circuit in the outer tube to external conductors. In an alternative embodiment, the position detector includes a threaded adapter threadingly mountable within an end wall of a pressurized fluid operated cylinder. Conductors extend from the circuit in the outer tube through the adapter to an external connector.

Abstract: A float for a liquid level detection apparatus including a tube extendable through liquid in a tank. The float is a buoyant body slidably mounted about the tube and having a diameter passable through an aperture in the tank. The float is preferably formed of two separate bodies joined by spacers positioned to allow the body to pivot from a first position substantially axially in line with the tube for insertion and removal of the float with respect to the tank to a second position substantially perpendicular to the tube in operative floating engagement with the liquid surface in the tank. The spacers, in one embodiment, are in the form of pins arranged in pairs along opposite side edges of the two bodies and spaced apart along the length of the two bodies such that the innermost pins of the two pairs of pins define an aperture for mounting the bodies transversely about the tube in the second, floating position.

Abstract: A drive circuit for a photoelectric sensor which automatically adjusts the sensor response time with adjustments in the drive current to the light source based on a desired sensing distance. The drive circuit includes an oscillator for establishing an output signal having an output frequency. An output of the oscillator is provided as an input to an adjustable current source. The current source is connected to the light source for providing the drive current to the light source at the output frequency. A peak detector is connected to a lead of the light source for detecting a feedback voltage proportional to the drive current through the light source. The feedback voltage is provided as an input to the oscillator, and the output frequency of the oscillator is variable depending on the feedback voltage so that variations in the drive current result in corresponding variations in the output frequency and, therefore, the frequency of the drive current.

Abstract: An Integrated controller for a commercial vehicle air conditioning system according to the present invention includes a central control unit in communication with a high-pressure switch or sensor, a low-pressure switch or sensor, and an evaporator thermostat. The central control unit includes outputs that control the air conditioning system compressor and fan according to the conditions detected by the high pressure switcher sensor, the low pressure switch or sensor, and the evaporator thermostat.

Abstract: An infrared heat source is directed through a chopper or modulator and beam splitter to the surface of the water. A pair of radiometers are provided, one located behind the back surface of the wafer to measure transmittance, the other adjacent to the beam splitter to measure wafer reflectance. The wafer temperature may then be calculated using an experimentally determined relationship between wafer radiance W.sub.W and wafer temperature, with wafer radiance being provided by the relationship ##EQU1## where r.sub.BS is the reflectance of the beam splitter, W.sub.W is the blackbody radiance of the wafer, W.sub.a is the blackbody radiance equivalent to ambient temperature, and e.sub.W is the wafer emittance. Alternatively, rather than locate a radiometer behind the wafer to measure wafer transmittance, a mirror may be located behind the wafer to reflect the transmitted energy back through the wafer on a periodic basis for a short part of each duty cycle.