Abstract: Systems and methods for switched mode power amplification are disclosed herein. A circuit is provided comprising an amplifier network, a DC translation stage for receiving input voltage from the amplifier network and for providing an output voltage to a voltage boost circuit, and a feedback network for providing feedback from the voltage boost circuit to the amplifier network.

Abstract: A motor driver high current protector includes a voltage source, a current sensor, a comparator, a switch, a delay circuit, and an inhibitor. The current sensor is configured to sense current passing through the motor driver and output a voltage responsive to the sensed current. The comparator has an output and is configured to generate a low voltage at its output while the output of the current sensor exceeds a first reference voltage. The switch has an input, an output, and a base. The base is activated by a low voltage at the output of the comparator to close the switch. Closing the switch provides electrical connection between the input and the output of the switch. The input of the switch is connected to the voltage source. The delay circuit is connected to the output of the switch and is configured to delay the voltage at the output of the switch while the switch is open. The delay circuit may include a resistor and a capacitor each connected to the output of the switch.

Abstract: The present invention provides a device for sensing when a portable memory element (“PME”) has been properly inserted and secured within a receiving port. The present invention achieves the objective by recognizing a change in an inductive current once a locking device properly secures the PME within an optimal location of the receiving port.

Abstract: A motor driver high current protector includes a voltage source, a current sensor, a comparator, a switch, a delay circuit, and an inhibitor. The current sensor is configured to sense current passing through the motor driver and output a voltage responsive to the sensed current. The comparator has an output and is configured to generate a low voltage at its output while the output of the current sensor exceeds a first reference voltage. The switch has an input, an output, and a base. The base is activated by a low voltage at the output of the comparator to close the switch. Closing the switch provides electrical connection between the input and the output of the switch. The input of the switch is connected to the voltage source. The delay circuit is connected to the output of the switch and is configured to delay the voltage at the output of the switch while the switch is open. The delay circuit may include a resistor and a capacitor each connected to the output of the switch.

Abstract: A feedback control system has two sinusoidal quadrature position feedback signals generated by photosensitive detectors that sense light reflected from (or transmitted through) position encoding strips that have a reflectance (or transmissivity) that varies sinusoidally along the length of the strip. The system may have one position encoding strip, with two photosensors offset along the length of the strip to provide a ninety degree phase offset. Alternatively, the system may have two strips that are offset in phase by ninety degrees. An error signal is produced directly within the servo loop without requiring computation of ARC-SIN or ARC-COSINE. The error signal is continuous, and position error is not sensitive to photosensor gain.

Abstract: A method and apparatus for automatically adjusting the light intensity output of a fluorescent lamp of a document scanner. The fluorescent lamp current level control apparatus comprises preheating circuitry for applying low voltage pulses of alternating polarity across filaments of the lamp, the low voltage pulses sufficient to preheat the filaments but insufficient to cause the lamp to fluoresce; high voltage circuitry for applying high voltage pulses of alternating polarity across the lamp, the high voltage pulses sufficient to cause the lamp to fluoresce; and control circuitry for receiving a first signal (PWM (D)) indicative of a desired level of current in the filaments, sensing a current indicative of the actual level of current in the filaments, and controlling the high voltage circuitry to cause the actual level of current to tend toward the desired level of current.

Abstract: A sightless indicating system and method is disclosed that is useful as an indicating device for diverse equipment, including equipment such as an electronic calculator, and is particularly useful by a blind person. When utilized as a part of an electronic calculator, a standard calculator keyboard is modified to include a sign key and an output key so that an operator can initiate output indications and determine the sign of such indications in addition to initiating the customary numerical and function inputs. The customary numerical and function inputs are processed in conventional manner except that the calculator output is converted to a sightless indicating form, such as audible signals indicative of output.