摘要:
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). Apparatus for conditioning the output signals includes a transistor sensitivity control (180, 382A, 382B), a transducer sensitivity adjustment (344A, 384B, or 436) a signal limiting control (226, 394, 396), a signal limiting adjustment (438), a null offset device, or null-width generator (418, 130A/#?, 150A/#?), a rate-of-change controller (144A/#?), a turn signal conditioner, or steering sensitivity control (160, 170, 398, 400, 416), a steering sensitivity adjustment (434), a nonlinear device (420) that functions as a steering sensitivity control, a nonlinearity adjustment (422) that functions as a steering sensitivity adjustment, and a microprocessor (432) that may be used to perform some, or all, of the aforesaid functions.
摘要:
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.
摘要:
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). Frequency response limitation caused by the low-pass filter (210) is obviated by using the derived signal to modulate the forward path (204) substantially simultaneously with modulation of the feedback path (206).
摘要:
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. modulation of the feedback path (16) optionally includes changing the frequency in the feedback path (16) as a function of the frequency of a modulation oscillator (64), changing the frequency in the feedback path (16) by a plurality of pulses for each cycle of the modulation oscillator (64), removing pulses from the feedback path (16), adding pulses to the feedback path (16), dividing the frequency in the feedback path (16) by higher and lower dividing ratios, preventing one cycle in the feedback path (16) from developing a "high" in the feedback path (16), holding a "high" in the feedback path ( 16) between two adjacent pulses, mixing quadrature frequencies with the feedback frequency in the feedback path (16), changing one input to a variable modulus divider (48) by means of a parallel adder (272), and using logic elements (148) to remove pulses from the feedback path (16).
摘要:
A clip connector seaming apparatus having upstanding projections arranged in sections to point inwardly on the lateral and longitudinal axes adapted to join a plurality of modular floor covering units comprising a modular floor covering is provided. The clip connector may comprise a releasable silicone backing and a pressure sensitive tape to affix or “tack” the clip connector to a supporting surface. The clip connector does not require any spray adhesives or additional glue to affix floor covering units to a support surface and is resistant to wear, moisture, excessive force. The clip connector may also be reusable to provide for replacing individual floor covering units.
摘要:
A feedback gate bias circuit for use in radio frequency amplifiers to more effectively control operation of LDFET, GaNFET, GaAsFET, and JFET type transistors used in such circuits. A transistor gate bias circuit that senses drain current and automatically adjusts or biases the gate voltage to maintain drain current independently of temperature, time, input drive, frequency, as well as from device to device variations. Additional circuits to provide temperature compensation, RF power monitoring and drain current control, RF output power leveler, high power gain block, and optional digital control of various functions. A gate bias circuit including a bias sequencer and negative voltage deriver for operation of N-channel depletion mode devices.
摘要:
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).
摘要:
A feedback gate bias circuit for use in radio frequency amplifiers to more effectively control operation of LDFET, GaNFET, GaAsFET, and JFET type transistors used in such circuits. A transistor gate bias circuit that senses drain current and automatically adjusts or biases the gate voltage to maintain drain current independently of temperature, time, input drive, frequency, as well as from device to device variations. Additional circuits to provide temperature compensation, RF power monitoring and drain current control, RF output power leveler, high power gain block, and optional digital control of various functions. A gate bias circuit including a bias sequencer and negative voltage deriver for operation of N-channel depletion mode devices.
摘要:
A clip connector seaming apparatus having upstanding projections arranged in sections to point inwardly on the lateral and longitudinal axes adapted to join a plurality of modular floor covering units comprising a modular floor covering is provided. The clip connector may comprise a releasable silicone backing and a pressure sensitive tape to affix or “tack” the clip connector to a supporting surface. The clip connector does not require any spray adhesives or additional glue to affix floor covering units to a support surface and is resistant to wear, moisture, excessive force. The clip connector may also be reusable to provide for replacing individual floor covering units.
摘要:
A seaming apparatus is formed from an elongated plate that is inextendible in both longitudinal and lateral directions. An upper surface of the plate is divided into multiple, transversely spaced and longitudinally extending zones. In the preferred embodiment, three such zones, including two edge zones spaced by a central zone, are provided. Numerous elongated upstanding sharp projections are provided in each of the edge zones and an adhesive layer is provided in the central zone. A peelable protective cover is arranged atop the adhesive layer. A thin adhesive layer with a peelable protective cover may be placed on a lower surface to secure the seaming apparatus to a supporting surface.