Abstract: Apparatus (70, 80, 90) and method are provided for selectively proportioning, or hot-switching, rf power to a plurality of rf outputs. The method includes: splitting a single rf signal into a plurality of split rf signals using power splitters (12, 36, 38A, 38B); separately power amplifying the split rf signals into the plurality of rf power outputs in solid-state current devices (Q1, Q2, Q3, Q4); selectively proportioning gains of the power amplifying steps; and maintaining a total rf power substantially constant during the selectively proportioning step. Preferably, the method includes series connecting the solid-state current devices (Q1, Q2, Q3, Q4) in series between a dc source-voltage (VDC) and a lower dc voltage; and performing the separate amplifying steps in the series-connected solid-state current devices (Q1, Q2, Q3, Q4). The selective proportioning step includes adjusting gate voltages of the solid-state current devices (Q1, Q2, Q3).

Abstract: A rotomolded plastic wall and ladder structure (10, 50, or 58)), which may be an article such as a window well (10) or a manhole (50 or 58), includes a thermoplastic wall (12), a ladder (16) whose rungs (18) each include an elongated metallic core (20) and a thermoplastic sleeve (22). Mold apparatus (70) includes a thermoplastic rotomold (72), an elongated hollow metallic core (20) having a heating passage (74) therein, and means for flowing hot air through the heating passage (74). The method includes disposing the hollow metallic core in a mold, placing a quantity of a thermoplastic inside a mold, heating the mold, rotating the heated mold, flowing heated air through the hollow metallic core, and bonding a layer of the thermoplastic onto the hollow metallic core.

Abstract: Variable phase-shifting rf power amplifiers (10, 30, 50) shift rf outputs at any angle up to 90, 180, or 270 degrees, respectively, while maintaining an rf output substantially constant. The variable phase-shifting rf power amplifiers (10, 30, 50) include two to four field-effect transistors (Q1, Q2, Q3, Q4) that are interposed between phase splitters and combiners, and that are connected in series between a source voltage and a lower voltage. Phase shifting is achieved by selectively and variably controlling amplification of the field-effect transistors (Q1, Q2, Q3, Q4). Selective and variable control of amplification is achieved by separately and variably controlling gate voltages of the field-effect transistors (Q1, Q2, Q3, Q4), whereby a difference between the source voltage and the lower voltage is used selectively by one of the field-effect transistors (Q1, Q2, Q3, Q4) and selectively proportioned between two of the field-effect transistors (Q1, Q2, Q3, Q4).

Abstract: Divided-voltage FET amplifiers (10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 130, 140, 150, 160, 170, 180, 200, or 220) include two or more solid-state current devices, preferably gallium arsenide FETs, (Q1, Q2, Q4, Q5, Q6, and/or Q8), connected in series or series-parallel for dc operation, and connected in parallel for rf operation, thereby improving power efficiency by using the same current two or more times to develop rf power. Various ones of the embodiments produce separate rf outputs, separately amplify two rf outputs and subsequently combine them into a single rf output, and/or selectively phase shift rf outputs. Isolation between rf frequencies and dc voltages includes using decoupling capacitors with selected resonant frequencies and low effective series resistances (ESRs) and using inductors with selected self-resonant frequencies for rf chokes.

Abstract: Apparatus (40, 70, and 80) and method are provided for minimizing power losses when combining rf signals in conductors (50A, 50B, 62A, and 62B) that are at quadrature phase angles. The method includes: mixing rf signals that are at quadrature phase angles; producing a dc voltage from the mixing step that is a function of a phase-angle deviation from quadrature; and correcting the phase-angle deviation. The correcting step includes tuning a length of a selected one of two rf conductors. Preferably, the method also includes equalizing amplitudes of the rf signals. When the method includes series connecting upper (Q1) and lower (Q2) solid-state current devices, the step of equalizing amplitudes of the rf signals includes adjusting a bias voltage of one (Q1) of the solid-state current devices.

Abstract: Apparatus, such as a wheelchair (10) is proportionally controlled by output signals produced by an X-Y input device (26, 58, 90, 100, 110, 360, or 370), which may be attached to head (90), a hand (112) or some other body component, and which may be actuated by tilting. The output signals are conditioned prior to application to the wheelchair (10).

Abstract: A building ornament, building ventilator, roof ventilator, or cupola (10 or 50), includes a top portion (12 or 52), a base portion (14 or 54), one portion (12, 14, 52, or 54) preferably is translucent. Optionally, the cupola (10 or 50) includes an illumination unit (82), elongated ventilation slots (32, 74), a plastic screen (76), to exclude bugs, that preferably is welded into one of the portions (52 or 54), and multiple V-shaped flanges (92A, 92B, or 92C) of different pitches that provide means for attachment to double-pitched roofs (42) having different pitches (40A, 40B, or 40C).

Abstract: A frequency-hopping oscillator (72, 136, 170, or 190) includes a phase-locked oscillator (74, 152, 172, or 196). The phase-locked oscillator (74, 152, 172, or 196) includes both a digital integrator (82 or 146) and a lead compensator (84, 148, or 180), and uses either analog (108) or digital (184) summation of integration and lead-compensation signals to provide a lead-compensated digital integrator (86, 150, or 182). The frequency-hopping oscillator (72, 136, 170, or 190) is adaptive in that it develops channelizing voltage via analog components, such as a VCO 20 and an improved D/A converter 98. The improved D/A converter 98 is designed to prevent “holes” even if a larger number of bits are processed using low-precision resistors.

Abstract: Digital-to-analog converters (282, 292, 310, 340, or 370) produce intentionally nonlinear outputs. When outputs of a plurality of lower bits are replaced by a next higher bit, a downward step (281 or 330) is produced in an output voltage (276, 332, or 336). Each of the downward steps (281 or 330) results in production of substantially equal output voltages in response to two different digital numbers being inputted. The digital-to-analog converters (282, 292, 310, 340, or 370) of the present invention are useful in frequency-hopping oscillators (72, 136, 170, or 190), in phase-locked oscillators (10, 74, 152, 172, and 196), and in other electronic systems that include a learning path (222, 224, or 226) with a digital-to-analog converter.

Abstract: A phase locking oscillator (60, 70, 80, 90, or 110) and a radio frequency oscillator (62, 72, 82, 92, or 112) achieve reduced incidental frequency modulation. A frequency-deviation sensitivity is reduced by a divider (66 or 100) that reduces a frequency-control voltage, thereby decreasing voltage spikes and other electrical noise, and thereby reducing incidental frequency modulation. In embodiments having an AC voltage divider (66), the frequency-control voltage is reduced when a frequency thereof is above a predetermined roll-off frequency. Below the roll-off frequency, the voltage dividing function ceases, and full deviation sensitivity of the radio frequency oscillator (62, 72, or 82) is restored, whereby a capture range of the phase locking oscillator (60, 70, or 80) and a maximum frequency range of the radio frequency oscillator (62, 72, or 82) are restored.

Abstract: A vehicle and luggage box assembly (40) includes a vehicle (42) and a luggage box (44). The luggage box (44) includes an open-ended chamber (61) with a flange (62) that extends perimetrically around an open end (49). A perimetrical chamber (66) is molded inside the flange (62). A perimetrical groove (68) is cut through the flange (62) and into the perimetrical chamber (66), thereby forming a perimetrical T-slot (70). A resilient gasket (72) is inserted perimetrically into the perimetrical T-slot (70), and a door (48) of the vehicle (42) closes against the resilient gasket (72). The molding process forms two separate chambers (66 and 94) in a single mold (100) by constructing a throat opening (122) with a dimension (120) that results in bridging across the throat opening (122), and that thereby results in the perimetrical chamber (66) being isolated from the closed chamber (94). Subsequently, removal of a web (92) transforms the closed chamber (94) into the open-ended chamber (61).

Abstract: A method for making an article of manufacture (10 or 34) includes making a PVC structural element (12 or 36) with a surface (26), adhesively securing a sheet of stranded material (22) to the surface (26), and molding a sponge material (16 or 40) to the sheet of stranded material (22). The sheet of stranded material (22) is a woven material or nonwoven mat. Securing the sheet of stranded material (22) to the surface (26) includes chemically softening a layer (18) of the structural element (12 or 36) by applying a solvent, applying a plastic cement layer (20) to the softened layer (18), partially embedding the sheet of stranded material (22) into the layer (20) and/or into the layer (18), thereby at least partially encompassing a plurality of first portions (28) of strands (24), and molding the sponge material (16 or 40) onto the partially-embedded sheet of stranded material (22), thereby at least partially encompassing a plurality of second portions (30) of the strands (24).

Abstract: Signal processing apparatus (410) includes a phase-locked oscillator (200, 236, 310, 330, 390), having a closed loop with both forward (204) and feedback (206) paths, that is a part of a larger closed loop (438). The larger loop (438) is phase locked to the phase-locked oscillator (200, 236, 310, 330, 390) by a signal derived from the larger closed loop (438) that modulates the feedback path (206), and by an output frequency of the phase-locked oscillator (200, 236, 310, 330, 390) that is delivered to the larger loop (438). Modulating the feedback path (206) either adds pulses to the feedback path (206) or removes pulses, thereby causing irregularities in the flow of pulses. A low-pass filter (210) in the feedback path (206) obviates these irregularities, thereby also obviating incidental frequency modulation (IFM) in the output of the phase-locked oscillator (200, 236, 310, 330, 390).

Abstract: A system (200) provides control of speeds and positioning of linear or rotary actuators (14A, 14B, 342A, 342B), and the system (200) may be used to control both speeds and steering of a conveyance (10). A transducer sensitivity control apparatus (202) provides selective control of sensitivity of transducers (28A, 28B) in an X-Y controller (26). The X-Y controller (26) delivers voltages to a steering sensitivity control apparatus (156, 180) that decreases, differences as an inverse and nonlinear function, in the two voltages supplied by the X-Y controller (26), thereby reducing steering sensitivity of the conveyance (10), increasing controllability in turns by decreasing sensitivity of joystick (34) movement, and/or automatically slowing the conveyance (10) when making sharp turns.

Abstract: Apparatus (10) for applying floor coatings (11) in selectively predetermined thicknesses (12) includes an elongated handle (16) that is attached to an elongated spreader blade (13), a pair of cams (28 or 56) that are attached to ends (14A and 14B) of the spreader blade (13) by means of studs (26), so that the spreader blade (13) is suspended above a surface (53) of a floor (54) by cam-determined distances (52), and each stud (26) includes an indexing-shaped portion (36) that cooperates with an indexing-shaped hole (44 or 60) in the cams (28 or 56) to provide selective rotational indexing of the cams (28 or 56).

Abstract: A rake (140) includes an elongated head (142) and an elongated handle (144). The elongated head (142) includes a white-metal extruded head blank (148) with a tooth-blanking flange (154) and a handle-attaching flange (158). A plurality of rake teeth (186) are blanked, or otherwise defined, in the tooth-blanking flange (154). A pair of identical handle-attaching brackets (202) each having both a semi-cylindrical portion (206) and a flange portion (208) are used to attach the elongated handle (144) to the elongated head (142). The elongated head (142) includes a lifting portion (162) that cooperates with the rake teeth (186) in a raking step, an ironing portion (166) that provides an ironing step, and a secondary smoothing portion (170) for use in a supplemental smoothing step.

Abstract: Wheeled apparatus (10) is usable both as a wheeled walker and as a wheelchair. The wheeled apparatus (10) includes a foldable frame (12 or 258), first (16A) and second (16B) transversely spaced-apart wheels that are attached to the frame (12 or 258) with a negative camber angle, a third wheel (24A) that is longitudinally spaced from the first (16A) and a second (16B) wheels and that is attached to the frame (12 or 258), and a seat cushion (97) that is attached to the frame (12 or 258). When used as a wheeled walker, bi-directional seat (101, 124, 146, or 162) provides rearward facing seating (186) for resting, and when used as a wheelchair, the bi-directional seating means (101, 124, 146, or 162) provides forward facing seating (187). Centers (94) of handgrips (82A and 82B) are disposed longitudinally intermediate of the first and second wheels (16A and 16B) and the third wheel (24A) to minimize danger of the wheeled apparatus (10) tipping backwardly when used as a wheeled walker.

Abstract: A method for inserting an audio signal (132) into a composite video signal (10) having a front porch (24), a back porch (26 or 32), a horizontal sync pulse (20) with a leading edge (22), and a luminance portion (16) to provide an audio-on-video signal (222), includes removing one or more video parts (180, 200) at least partially from the luminance portion (16), sampling one or more audio parts (182, 202), biasing a zero magnitude (238) of the audio parts (182, 202) to the midpoint (240) of the maximum luminance magnitude (242), and placing the sampled parts (182, 202) at least partially within the luminance portion (16) of the composite video signal (10) to form the audio-on-video signal (222).

Abstract: A pig feeding mat (10) is provided for use over a grated floor (12). The pig feeding mat (10) includes a rectangular surface (14) having first and second ends (16 and 18) and a perimeter (20). A rim (22) around the perimeter (20) restrains movement of solid material transversely over the perimeter (20). A plurality of spaced-apart gaps (24) in the rim (22) allow liquid to drain from the pig feeding mat (10). Paired lugs (26and 28, or 32 and 34) disposed at respective ends (16 and 18) of the mat (10) are used to position the mat (10) under a partition (50 or 52) of a feeding stall (44) by invertedly straddling the mat (10). The mat (10) can be cut along a joggled groove (40) to separate the rectangular surface (14) into first and second surface portions (36 and 38), to be used in separate feeding areas (64 and 66).

Abstract: A D.C. modulated phase locked oscillator (60, 80, 100, 140, 160, 190, 220, 264, or 290) includes a phase locking oscillator (70, 90, 128, 180, 192, 222, 266, or 292) and a D.C. modulator (72, 92, 130, 156, 182, 194, 224, 268, or 294). Both a forward path (14) and a feedback path (16) are D.C. modulated. D.C.