A feedback architecture for a PWM switching audio amplifier is, capable of compensating the effects of the demodulation filter through at least two feedback paths of the voltage applied to a load without degrading the overall loop gain of the device. Each of the feedback paths may include a respective network or filter for compensating a respective frequency pole of the cascade low-pass filter+load and establishing a certain band pass. These networks or filters may be passive networks.

A feedback device 1 including an interface 2 for receiving a first signal 3 from a point of sale console 4. A processor 5 is responsive to signal 3 for selectively defining a second signal, in the form of an inaudible ultrasonic transmission 6. An output, in the form of an ultrasonic transducer 7, is responsive to processor 5 for propagating transmission 6 to provide only in a predetermined spatially defined transmission zone 8 an audible signal 9 indicative of signal 3. Signal 9 is substantiall...

A generally conically shaped cam formed internally of the actuator piston and a follower connected to a rotary shaft serves to provide a position feedback signal within a minimum of space.

Acoustical signals impinging on an input converter are converted into a first electric signal by a controllably variable transfer characteristic. The transfer characteristic is dependent on the angle at which the acoustical signals impinge on the input converter. The first electric signal is processed and a resulting signal is applied to an output converter. Feedback to be suppressed is compensated by a feedback compensating signal, which is generated in dependency of the resulting signal and is...

For reducing various adverse effects due to provision of a low-pass filter, while suppressing an oscillation generated therein, there is provide a feedback circuit, having at least one operational amplifier, having a low-pass filter in an output portion thereof, for feeding a signal from the output portion back thereto, including: a first feedback circuit portion for negatively feeding a signal from an input terminal of the low-pass filter back to an inverted input terminal of the operational am...

Disclosed are a system, method and device for generating an equalized signal from an input signal. Symbols in the equalized signal may be detected on each of a sequence of symbol intervals to recover a symbol value in the symbol interval. A feedback coefficient may be applied to a symbol value recovered in a previous symbol interval to generate the equalized signal in a current symbol interval. The feedback coefficient may be generated based, at least in part, on an estimated error associated wi...

An electrical feedback signal for an electrohydraulic servovalve is provided by electrical strain gauge means influenced by the bending of a cantilever beam one end of which is constrained to move in a frictionless manner with the output stage valve member of the servovalve, said strain gauge means including a strain sensitive element having a resistance value varied by bending of said beam thereby to generate an electrical feedback signal proportional to the displacement of said valve member wh...

An electroencephalophone which is battery operated and completely self-contained in a headset to be worn by the user and having a plurality of scalp electrodes carried on flexible leads permitting placement of the electrodes on the user's head when the headset is mounted thereon and having an electronic circuit and transducer for converting brain wave signals picked up by the electrodes into recognizable audio tones enabling the user to listen to his own brain wave generation. The scalp electrod...

Active materials having substantially time constant, spatially alternating variations in the propagation characteristics thereof produce laser oscillations when excited above a threshold of oscillation.

The displacement of a servoactuator such as a variable volume pump or motor is controlled by a servovalve of the jet discharge type having a movable jet tube which is responsive to an electrical input to establish a pressure differential between a pair of fluid lines in accordance with the magnitude of an electrical signal. The pressure differential is applied to operate the opposed hydraulic motors which position the displacement changing means of the pump or motor. A resilient feedback spring ...