Abstract: A circuit for decoding a high speed Manchester encoded digital communication signal is provided. The circuit includes a pair of latch circuits which are used to detect clock edges in the encoded signal for providing respectively set and reset pulses to a third latch circuit, an output of which comprises the decoded data of the Manchester code signal. Additional logic is provided to extract a clock signal from the Manchester code signal.

Abstract: An apparatus for use in measuring fetal blood flow characteristics. The apparatus includes a non-invasive pulse oximetry probe that is inserted into the uterus between the fetus and the uterine wall. The probe is deformable and is positively attached to the fetal tissue surface using a vacuum pump which causes the probe to deform from a pre-set curvature to the curvature of the fetal tissue surface and to form a gasket-type seal with the fetal tissue surface. The probe is manually inserted into the uterus using a curved insertion tool, and is shaped to fit through a slightly dilated cervix. In a preferred embodiment, the probe includes fetal and maternal ECG sensors and additional sensing devices, and is provided with apparatus for improving the efficiency of the pulse oximetry optics.

Abstract: An apparatus for testing the quality of a seal on a package overwrap having a cutting or burning element to create a hole in the package overwrap without breaching the integrity of the package; a measuring head for introducing super-atmospheric air pressure through the hole between the overwrap and the package; and a pressure transducer for determining whether the rate of air leakage from the overwrap is within acceptable limits.

Abstract: A headrail and bracket combination is provided in which the headrail comprises a main body portion in the form of a U-shaped channel the forward wall of which is suspended from a top plate of the bracket and also restrained against forward motion, and the rear wall of the main body is supported by a rear plate of the bracket, the bracket being adapted for mounting on a window frame. An end plate is also provided for the bracket for end mounting, which end plate can be removed from view either by breaking it off or by bending it backwardly out of sight.

Abstract: A current limit circuit is provided which may be used to limit the current conducted by a pass transistor in a low dropout voltage regulator circuit having no ground terminal. The output current of the regulator is sensed by a low value resistor in the collector of the transistor. The voltage developed across the resistor is proportional to the output current of the regulator, and is used to vary a current ratio which sets the current limit value. The gain of the current limit loop is increased by providing positive feedback during current limiting. A foldback network is provided which reduces the current limit value at higher input/output voltage differentials. The feedback provided by the foldback network has a breakpoint which is sensitive to the operating temperature of the regulator circuit.

Abstract: A circuit is provided for reducing the turn-off transition time of a switching PNP transistor by providing a reverse drive current to the base of the PNP transistor after the drive current has been removed from the base. The reverse drive current is generated by an NPN transistor, the emitter of which is connected to the base of the PNP transistor. A capacitor coupled to the base of the NPN transistor is charged and during the conducting period of the PNP transistor and discharged after the drive current is removed from the base of the PNP transistor to enable the base of the NPN transistor to be driven above the supply voltage connected to the emitter of the PNP transistor.

Abstract: A lighting fixture is provided which includes a rotatable lamp and reflector system which can be adjusted to direct its maximum candlepower at a desired vertical angle. The lighting fixture also includes a rotatable glareshield which can be adjusted to vary the height of the top of the shield to change the degree of shielding provided. The glareshield and the housing of the lighting fixture form an interchangeable unit which can be installed after wiring. The glareshield may be adapted to provide diffused or patterned backlighting. A removable supplementary baffle may be employed to prevent glare or reflected light from being viewed by a person beneath the lighting fixture, or to prevent undesired backlighting beneath the lighting fixture.

Abstract: A circuit is provided for distributing load current among multiple power transistors in an output stage, each power transistor being adapted to conduct current over a different range of collector-emitter voltages. The circuit includes a first power transistor having a large ballast resistance for conducting current between the input and output of the circuit when the input/output voltage differential is high, and a second power transistor having a small ballast resistance for conducting current between the input and output of the circuit when the input/output voltage differential is low. Both transistors respond to a single control signal, and buffering is provided to prevent either transistor from overloading the common control point. Individual current limit protection circuitry is provided for each transistor, including a foldback network which reduces the current limit value of the current limit circuitry when the input/output voltage differential reaches a threshold value.