Abstract: A logarithmic attenuator circuit includes a resistive attenuator in which the series resistors are P-channel MOSFETs with gate electrodes connected to V.sub.DD and the parallel resistors are P-channel MOSFETs which also function as switches. A control circuit (8B) produces a plurality of successive control signals (V1,2 . . . 10) on the gate electrodes of the successive MOSFETs which functions as switches in response to a gain control signal (V.sub.

Abstract: A color wheel includes a rotatable disc-shaped carrier to which three or more planar color filter segments are secured in radial fashion about the periphery thereof. The portions of the color filter segments extending beyond the peripheral portion of the carrier form a substantially continuous translucent color ring for being inserted into, and rotated through, a light path. Each of the color filter segments is formed of a continuous sheet of material without any apertures formed therein. The disc-shaped carrier has one or more recesses, or bonding zones, formed therein to receive innermost bonding portions of the color filter segments; these recesses provide stops for aiding in the proper radial and axial positioning of the color filter segments. The bonding portions of the color filter segments are secured to the bonding zone of the disc-shaped carrier by an adhesive. A further recess can be formed in the disc-shaped carrier adjacent each bonding zone to receive the adhesive layer.

Abstract: An optically readable data storage medium includes a thin film data carrier fabricated from first and second juxtaposed plastic layers. A microembossed data surface is positioned within an interface zone and includes physically displaced surface elements which encode digital data. An adaptor temporarily receives and supports the thin film data carrier from below and includes a centrally located aperture geometrically compatible with a standard CD player spindle to enable the adaptor to be supported and rotated by the spindle. The adaptor includes a refraction zone having an area and a location underlying the microembossed data surface to enable the light beam from the light source of the CD player to be focussed onto the rotatable data surface. The reflected light beam modulated by the digital data encoded within the microembossed data surface is intercepted and converted to an electrical signal by the CD player optical readout device.

Abstract: A catheter for use in an electrophysiological procedure to ablate a site includes a metallic tip having a first work function and energized by a source of RF energy. The RF energy return path is through a relatively large plate of a metallic material having a second work function and disposed at a location removed from the ablation site. The difference in work functions of the tip and the plate, operating in the presence of an electrolyte represented by intermediate tissue, produces an exchange of electrical charges through chemical reaction to create a galvanic cell. By loading the galvanic cell with a shunt resistor, it becomes a current source providing a current signal having a peak value representative of occurrence of tissue damage. This representation is used to regulate the RF energy applied to the ablation site.

Abstract: A digital-to-analog converter is provided which compensates for relative errors among weighting elements used for D/A conversion. The converter includes a decoder, a rotator, and a weighting section. The rotator receives decoded signals from a decoder to produce rotated output signals for activating or deactivating a plurality of weighting elements, respectively, included in the weighting section. The rotated output signals assure that the same number of weighting elements are activated in each of a plurality of sub-periods of time constituting a main period of time of the D/A conversion and that each of the plurality of weighting elements is activated the same number of times during the whole main period.

Abstract: A CMOS output circuit including a differential error amplifier (3) is operated to provide a stable quiescent bias current in an output MOSFET by causing a first current equal to a threshold voltage of a P-channel reference MOSFET (M1) divided by the resistance of a reference resistor (R1) to flow through an N-channel current mirror control MOSFET (M4). A first N-channel current mirror output MOSFET (M6) having a gate coupled to the gate of the N-channel current mirror control MOSFET (M4) and a drain coupled to a drain of the P-channel reference MOSFET (M1) causes a second current proportional to the first current to flow through the P-channel reference MOSFET (M1). The first current is controlled in response to feedback from the P-channel reference MOSFET (M1). A bias current in an error amplifier (3) is controlled in response to the N-channel current mirror control MOSFET (M4).

Abstract: A salve includes a water-miscible, hydrophilic cream vehicle, 1-22% by weight a-DFMO, and no absorption enhancer. The salve is preferably contained in an ointment tube permanently sealed at one end to preclude exposure to light and air. The salve is applied as a preventative in an appropriate amount twice daily to skin exposed to actinic radiation. An initial application of a salve including 10% by weight A-DFMO is preferred to minimize the risk of skin irritation without compromising the therapeutic value of the salve. The salve shows no systemic uptake, thereby eliminating systemic toxicities that result from other techniques for administering the drug.

Abstract: A power-saving column driver integrated circuit, and a power-saving method for driving a liquid crystal display, include a series of multiplexers coupled to the columns of the display. The multiplexers selectively couple each of the columns to a common external storage capacitor during a portion of each row drive period for discharging each of the pixels in the selected row of the liquid crystal display to a median bias voltage. During the remaining portion of each row drive period, the multiplexers selectively couple voltage drivers to the columns of the LCD pixel array for applying a desired driving voltage to each column of the array. The polarity of the driving voltages applied to each column alternates on succeeding row drive periods, and the resulting voltage that is summed on the storage capacitor averages to the median bias voltage.

Abstract: A programmable controller includes a photodetector for receiving data as pulses light from a video display and infra-red emitting diodes for transmitting pulses of light in a format recognized by the device to be controlled. The light from the video display is produced by generating a series of vertically displaced, horizontal lines on the screen of the display. Each line corresponds to a pulse of light and to one bit of information and one or more bytes are displayed per frame on the display. The display produces two initial lines that define a timing window for receiving the remaining data and produces a terminal line that toggles for error detection. The controller produces pulses in the format required by the controlled device by executing a sub-set of primitives from a set stored in the controller. The primitives are executed in a sequence determined by the data from the video display.

Abstract: An armored housing has resiliently supported therein the combined weight of a reflector structure, a lamp in the reflector structure and an electrical component, such as a ballast, mounted on the reflector structure. The reflector structure preferably comprises an extruded aluminum reflector support and a sheet metal reflector.

Abstract: An operational amplifier circuit includes a differential operational amplifier and a common mode feedback circuit with first and second transistors (16 and 20) having source electrodes connected to first and second supply voltage conductors and drains coupled to first and second outputs of the operational amplifier, respectively. First and second capacitors (24 and 25) are connected in series between gate electrodes of the first and second transistors and have a common point connected to the first output. A first switch capacitor circuit periodically refreshes the first capacitor to a voltage equal to the average of the first and second supply conductor voltages minus first and second predetermined bias voltages, respectively. A second similar common mode feedback circuit is coupled to the second output a differential output voltage produced by the operational amplifier results in equal excursions of the first and second outputs on opposite sides of the common mode feedback signal.

Abstract: A touchpad, which may include a keypad array, digitizing tablet, touch screen or an electronic mouse, is operable through a suitable dielectric medium, operating by capacitive effect and suitable for use as a computer interface in conjunction with a monitor screen, or as a computer input device in a number of applications, for example, as a cash till keypad.

Abstract: A probe for use with a catheter in an electrophysiological procedure to map and to ablate any of several tissue sites without repositioning the probe includes a metallic tip and a plurality of metallic rings, each tip and ring having a first work function and energized by a source of RF energy. The RF energy return path is through a further electrode of a metallic material having a second work function and disposed at a tissue location removed from the ablation site. After the sites have been mapped and one or more sites are selected for ablation, the selected site(s) is ablated prior to any repositioning of the probe. Regulation of the temperature at the ablation site(s) is achieved by sensing the temperature dependent current of a galvanic cell created by the tissue between the energized tip/ring and the further electrode due to their different work functions.

Abstract: A plurality of tabs extend from three edges of each head of a pair of heads for penetrably engaging respective ones of a plurality of slots disposed along opposed edges of a wrap to form an asparagus box. The pair of heads and wrap are formed from corrugated plastic sheet material and the wall segments present in opposed overhangs of each tab engage opposed triangular elements disposed at opposed ends of each slot to restrain the tab but accommodate disassembly and reassembly. A tray receives and supports the open end of the asparagus box to form a container and includes a plurality of slots for receiving tabs protruding from the wrap of an adjacent stacked container to stabilize stacking of the containers.

Abstract: An integrating circuit includes an operational amplifier and an integrating capacitor which is decoupled from the output of the operational amplifier and precharged to a positive reference voltage before each integration cycle. During each integration cycle the operational amplifier output decreases from the reference voltage toward but not below ground. This allows the operational amplifier to be included as a front-end integrator to a delta-sigma analog-to-digital converter that is powered only by a single power supply. In the described embodiment, the output is coupled to an input of an auto-zeroing stage which provides negative feedback to stabilize the operational amplifier when the integrating capacitor is disconnected during precharging and a bandwidth control input which couples a larger compensation capacitance to reduce the bandwidth during integration to reduce RMS noise.