Abstract: A system for a two-step activation for a valve includes at least one valve control selector having an output representative of a valve position and a touch sensor having an output representative of a permission to operate said valve.

Abstract: A signal comparison circuit is provided which exhibits a change in its hysteresis as a function of changing temperature. The change in the hysteresis is accomplished by arranging first and second transistors in association with each other and in association with a feedback resistor of a comparator. The known variation in base-emitter voltage drop of transistors as a function of changing temperature is taken advantage of by the comparison circuit and the voltage at the feedback resistor of a comparator is changed as a function of temperature change. As a result, the hysteresis is decreased as a result of increasing temperature and increased as a result of decreasing temperature so that changes in signal magnitude of first and second input signals does not adversely affect the ability of the circuit to respond to changes in the difference between the first and second input signals and properly provide an output signal at the correct time.

Abstract: A pressure transducer circuit is provided which includes a bridge arrangement of piezoresistors which are connected to a diaphragm that is sensitive to a pressure which is monitored. The output of the sensor bridge is provided to a preamplifier which is, in turn, associated with an attenuation network and compensation circuitry. The transducer incorporates a plurality of temperature sensitive resistors within the compensation circuit and these temperature sensitive resistors are produced at the same time and during the same manufacturing step as the piezoresistors of the bridge arrangement. In addition, they are produced using the same dopant and are implanted or diffused in the same semiconductor layer as the piezoresistors. The pressure transducer circuit incorporates a plurality of trimmable resistors which are adjusted during a calibration stage to compensate for temperature variations and nonlinearity of the numerous components in the circuit.

Abstract: A Hall element switching system which provide clean switching and wherein the system operate and release points are the same. The system includes a Hall element, first and second comparator circuits and a feedback circuit. The Hall element is the sensing part of the system and produces a voltage output which is proportional to the strength of the magnetic field impinging thereon. The output of the Hall element controls the switching of the first and second comparator circuits. The second comparator circuit, in turn, controls the output of the feedback circuit. The feedback circuit output is connected to the input of the first comparator circuit and can be at one of three levels. The feedback circuit by being connected to the input of the first comparator circuit causes a shift in the operate and release points of the first comparator circuit. The output of the first comparator circuit is the system output.

Abstract: The output of a condition sensing bridge is linearized by providing a feedback from the output to the bridge supply which feedback is in the linear form of V.sub.B =KV.sub.O +V.sub.X where V.sub.B is the bridge supply voltage, K is a proportionality constant, V.sub.O is the bridge output and V.sub.X is the feedback offset voltage.

Abstract: A hoop, in collapsed configuration fitting readily into the mouth of a plastic trash bag, is formed from a synthetic resionous material and is peripherally expandable from its collapsed form to fit tightly against the inner surface of the bag and hold the bag securely in place with the mouth open. The hoop has provision for either free-standing use with the bag mouth in the vertical position, when trash may be swept directly into the opening, or mounting on a vertical support with the bag mouth in the horizontal position for use as a trash receptacle. A pan attached by a flexible integral connection to the hoop serves both as a threshold when sweeping trash into the bag, and as a lid when the bag is used as a trash receptacle. The flexible integral interconnection of the hoop and pan also permits compact storage and transportation of the holder in assembled form, and even greater space savings when stored or shipped in "blank" form as one flat integral unit.

Abstract: A hoop, fitting readily into the mouth of a plastic trash bag, is peripherally expandable to fit tightly against the inner surface of the bag and hold the bag securely in place with the mouth open. The hoop has provision for either free-standing use with the bag mouth in the vertical position, when trash may be swept directly into the opening, or mounting on a vertical support with the bag mouth in the horizontal position for use as a trash receptacle. A pan attached by a hinge to the hoop serves both as a threshold when sweeping trash into the bag, and as a lid when the bag is used as a trash receptacle. The hinged pan also permits compact storage and transportation.

Abstract: A linear Hall effect integrated circuit in which the output signal of a Hall element formed in an epitaxial layer is amplified by an amplifier circuit whose gain is determined by a resistor partially formed in the same epitaxial layer. A first amplifier stage configured as a voltage to current converter is connected through a current mirror to a second amplifier stage configured as a current to voltage converter. The current bias for the first amplifier stage is controlled by a resistor also partially formed in the epitaxial layer.

Abstract: A Hall effect device with offset compensation in which the output terminals of a Hall effect element formed in an epitaxial layer are connected to a differential current source. The sum of first and second currents produced by the source is determined by a resistor formed in the epitaxial layer in which the Hall effect element is formed and which is powered by the same electrical source as the Hall effect element so as to produce a current which tracks the current through the Hall effect element with temperature. The current through the resistor is split by a pair of trimmable temperature insensitive resistors and supplied to a pair of cross-coupled current mirrors which supply the currents to the output terminals of the Hall effect element.