Abstract: A drive circuit (18) produces a drive signal for a pump (10) having a piezoelectric actuator (14), with the piezoelectric actuator (14) forming a part of the drive circuit (18) and serving to shape a waveform of the drive signal. The drive circuit (18) comprises a pulse generator (100) which generates pulses; a converter circuit (102) which receives the pulses and produces charge packets at a rate which equals a desired drive frequency; and, the piezoelectric actuator (14). The piezoelectric actuator (14) receives the charge packets and, by its capacitive nature, integrates the charge packets to shape the waveform of the drive signal. Preferably, the piezoelectric actuator (14) integrates the charge packets to yield a drive field that approximates a sine wave. In one non-limiting example embodiment, the pulse generator (100) comprises a microcontroller-based pulsed width modulator (PWM) circuit (116) and the converter circuit (102) comprises a flyback circuit.

Abstract: The present invention relates to novel compounds that are novel adenosine receptor analogues. Specifically, the compounds of the present invention preferably function as both adenosine receptor agonists and ganglionic blocking agents. To achieve this functionality, the compounds of the present invention, preferably contain a ganglionic blocking motif, is inserted into the adenosine molecule. The ganglionic blocking motif preferably includes an elongated carbon chain that, in a particularly preferred embodiment, contains two terminal amino groups. The ganglionic blocking motif preferably includes a carbon along the elongated carbon chain that is integral to a cyclic ketal that is part of the adenosine molecule. In presently-preferred embodiments, the elongated carbon chain ranges from two to sixteen carbons in length. The compounds of the present invention will be useful for treatment of a variety of conditions including, but not limited to, hypertension, vasodilation, and ischemia.

Abstract: The present invention includes a novel class of synthetic adenosine derivatives having clinically relevant and useful properties. These adenosine cyclic ketal compounds will be useful for treatment of a variety of conditions including, but not limited to, hypertension, vasodilation and ischemia.

Abstract: An automatic switched power receptacle includes an outlet receptacle adapted to receive a plug. A relay is connected between the power receptacle and a source of power to selectively power the receptacle. A plug presence sensor in proximity to the receptacle senses presence of a plug in the receptacle. The plug presence sensor comprises a light source and light sensor, the light source and light sensor being disposed on opposite sides of a path of movement of a plug being inserted in the receptacle. An automatic control circuit is connected between the relay and the plug presence sensor for selectively energizing the relay to power the receptacle incident to the sensor sensing presence of a plug.

Abstract: A plug presence sensor comprises an LED and a light sensor in the form of a photo-transistor which senses presence of a plug in a receptacle. The sensor is monitored by a microcontroller to control latching of a relay. The microcontroller de-energizes the relay, so that no power is present at the receptacle, when no plug is inserted. When the plug is inserted, then the microcontroller causes the relay to be energized to provide power to the receptacle. The microcontroller is preprogrammed to communicate with a remote master controller. In the event that a loss of communication occurs between the microcontroller and the master controller, the microcontroller automatically de-energizes the relay so that no power is present at the receptacle. A communication error output signal is connected to an override circuit including a capacitor which differentiates an edge of the communication error signal to inject a pulse onto the plug presence sensor signal which simulates removal and reinsertion of the plug.

Abstract: A switched receptacle includes a latching relay selectively providing power to an outlet receptacle. A drive circuit for the latching relay provides indirect feedback to a logic controller which follows or tracks each relay operation to ensure that the relay is in the commanded mode.

Abstract: A control circuit synchronizes operation of a latching relay to extend contact life. The relay is switched using an H-bridge drive circuit. The synchronization is done using a two-step delay. The first delay is provided by a phase shifter, which delays the timing signals used by a logic controller relative to a zero crossing. The second delay is provided by an adjustable timer circuit including a potentiometer. The two delays are used so that the latching relay is tripped at a selectable time coinciding with the second zero crossing after a switching command is received.

Abstract: Disclosed is a method and apparatus for mixing internally generated or stored video with an external video and driving an LCD display device. External video is clocked into a dual port external frame store. Internal video is either internally generated or read from an internal mass store device and stored in an internal frame store and in a preferred embodiment, the internal video data includes an embedded code which serves to select on a pixel by pixel basis the appropriate frame store signal, either external or internal for display on the LCD panel. By adjusting the start number on row and column counters for reading out data from the external frame store, panning of an external video image can be accomplished. By repeating the readout of the external frame store selectively, a "zoom" of the image can be provided to an LCD display device.

Abstract: An electrical connector assembly includes a pair of spaced receptacle modules mounted to a first printed circuit board which is electrically coupled to a second printed circuit board spaced from and generally parallel to the first printed circuit board. A conductive ground plate is electrically coupled between the printed circuit boards and mechanically supports the circuit boards in their spaced generally parallel relationship. The ground plate is disposed perpendicular to the first and second printed circuit boards forming two separate compartments between the first and second printed circuit boards to provide electromagnetic interference isolation between the compartments. An electrical component such as transformer may be mounted on one side of the ground plate between the spaced generally parallel printed circuit boards, and the ground plate provides a heat sink for the transformer.

Abstract: Disclosed is a method and apparatus for converting interlaced input video to a sequential output compatible with sequential input display devices. The video input is digitized and decoded so as to provide separate luminance or chrominance information for each pixel to a line buffer memory. A line derived frequency reference from the input video serves to reference a pixel clock which clocks pixel information into the memory and clocks pixel information out of the memory at twice the pixel clock rate. The decoder also digitizes the luminance/chrominance information prior to storage in the memory and, as this information is read out of the memory, it is converted back into analog data by a suitable D-A converter and then is converted into appropriate format to provide red, green and blue video output information for operating sequential input devices.

Abstract: A negative pressure filtration device is used in conjunction with a containment enclosure for the removal of hazardous material such as asbestos insulation surrounding pipes in habitable buildings. The inventive negative pressure filtration device generates a negative pressure within the containment enclosure, which negative pressure is quantitatively adjustable and capable of being continuously monitored by the user. Advantageously, the negative pressure filtration device is small, lightweight, portable, battery-operated and reliable, for use in a wide variety of hazardous material removal scenarios. The portability and versatility of the negative pressure filtration device is achieved through the use of operational vacuum pressures and air flow volumes much smaller than those of known systems.