Abstract: A secure passive RFID tag system comprises at least one base station and at least one passive RFID tag. The tag includes a fiber optic cable with the cable ends sealed within the tag and the middle portion forming an external loop. The loop may be secured to at least portions of an object. The tag transmits and receives an optical signal through the fiber optic cable, and the cable is configured to be damaged or broken in response to removal or tampering attempts, wherein the optical signal is significantly altered if the cable is damaged or broken. The tag transmits the optical signal in response to receiving a radio signal from the base station and compares the transmitted optical signal to the received optical signal. If the transmitted optical signal and the received optical signal are identical, the tag transmits an affirmative radio signal to the base station.

Abstract: A smart passive RFID reader includes an RFID reader, a microcontroller providing a means for increasing the probability of detecting correct passive RFID tags and decreasing the probability of detecting incorrect passive RFID tags, and antennas connected to the RFID reader, wherein adjacent antennas have orthogonal polarization and the antennas each have a pivoting axis, whereby rotating the antennas about their pivoting axes causes a change in the overlap of the antenna beam radiation patterns and thereby provides a means for adaptive beamforming in order to improve tag reading.

Abstract: A smart passive RFID reader includes an RFID reader module, a microcontroller providing a means for increasing the probability of detecting correct passive RFID tags and decreasing the probability of detecting incorrect passive RFID tags, and antennas connected to the RFID reader module, wherein adjacent antennas have orthogonal polarization and the antennas each have a pivoting axis, whereby rotating the antennas about their pivoting axes causes a change in the overlap of the antenna beam radiation patterns and thereby provides a means for adaptive beamforming in order to improve tag reading.

Abstract: A circuit board anti-tamper mechanism comprises a circuit board having a frangible portion, a trigger having a trigger spring, a trigger arming mechanism actuated by the trigger wherein the trigger arming mechanism is initially non-actuated, a force producing mechanism, a latch providing mechanical communication between the trigger arming mechanism and the force producing mechanism, wherein the latch initially retains the force producing mechanism in a refracted position. Arming pressure applied to the trigger sufficient to overcome the trigger spring force will actuate the trigger arming mechanism, causing the anti-tamper mechanism to be armed. Subsequent tampering with the anti-tamper mechanism results in a decrease of pressure on the trigger below the trigger spring force, thereby causing the trigger arming mechanism to actuate the latch, thereby releasing the force producing mechanism to apply force to the frangible portion of the circuit board, thereby breaking the circuit board.

Abstract: Aspects of a transport dolly for repositioning a drive unit are described. In one embodiment, the transport dolly includes a base frame, an elevated handgrip bar, and a wheel lock assembly that locks at least one jack wheel of the drive unit into an engaged position for manual displacement of the drive unit using the elevated handgrip bar. The transport dolly may be relied upon to assist an individual with manual movement of the drive unit, by engaging and locking one or more jack wheels of the drive unit into a position which lifts the drive unit off the drive wheels of the drive unit. Once the jack wheels are engaged and locked in position, the drive unit may be more easily repositioned manually.

Abstract: A secure optionally passive RFID tag or sensor system comprises a passive RFID tag having means for receiving radio signals from at least one base station and for transmitting radio signals to at least one base station, where the tag is capable of being powered exclusively by received radio energy, and an external power and data logging device having at least one battery and electronic circuitry including a digital memory configured for storing and recalling data. The external power and data logging device has a means for powering the tag, and also has a means.

Abstract: A circuit board anti-tamper mechanism comprises a circuit board having a frangible portion, a trigger having a trigger spring, a trigger arming mechanism actuated by the trigger wherein the trigger arming mechanism is initially non-actuated, a force producing mechanism, a latch providing mechanical communication between the trigger arming mechanism and the force producing mechanism, wherein the latch initially retains the force producing mechanism in a refracted position. Arming pressure applied to the trigger sufficient to overcome the trigger spring force will actuate the trigger arming mechanism, causing the anti-tamper mechanism to be armed. Subsequent tampering with the anti-tamper mechanism results in a decrease of pressure on the trigger below the trigger spring force, thereby causing the trigger arming mechanism to actuate the latch, thereby releasing the force producing mechanism to apply force to the frangible portion of the circuit board, thereby breaking the circuit board.

Abstract: A secure optionally passive RFID tag or sensor system comprises a passive RFID tag having means for receiving radio signals from at least one base station and for transmitting radio signals to at least one base station, where the tag is capable of being powered exclusively by received radio energy, and an external power and data logging device having at least one battery and electronic circuitry including a digital memory configured for storing and recalling data.

Abstract: A secure passive RFID tag system comprises at least one base station and at least one passive RFID tag. The tag includes a fiber optic cable with the cable ends sealed within the tag and the middle portion forming an external loop. The loop may be secured to at least portions of an object. The tag transmits and receives an optical signal through the fiber optic cable, and the cable is configured to be damaged or broken in response to removal or tampering attempts, wherein the optical signal is significantly altered if the cable is damaged or broken. The tag transmits the optical signal in response to receiving a radio signal from the base station and compares the transmitted optical signal to the received optical signal. If the transmitted optical signal and the received optical signal are identical, the tag transmits an affirmative radio signal to the base station.

Abstract: A violin shoulder rest that facilitates the optimal positioning of a violin relative to a violin player's body for increased comfort and reduced physical stress, and facilitates the optimal positioning of a microphone relative to the violin to achieve the desired volume and tonal qualities of the sound produced by the instrument. The violin shoulder rest includes an elongated base conformable to a violin player's body, clamping members coupled at opposing ends of the base for clamping the shoulder rest to a violin, and a securement mechanism to secure the respective clamping members to the base. The violin shoulder rest accommodates at least one electrical signal input, and amplification circuitry or other signal processing circuitry for pre-amplifying or otherwise processing the electrical signal input. The violin shoulder rest is configured to mount a positionable microphone subassembly adjacent a respective signal input connector.

Abstract: A violin shoulder rest that facilitates the optimal positioning of a violin relative to a violin player's body for increased comfort and reduced physical stress, and facilitates the optimal positioning of a microphone relative to the violin to achieve the desired volume and tonal qualities of the sound produced by the instrument. The violin shoulder rest includes an elongated base conformable to a violin player's body, clamping members coupled at opposing ends of the base for clamping the shoulder rest to a violin, and a securement mechanism to secure the respective clamping members to the base. The violin shoulder rest accommodates at least one electrical signal input, and amplification circuitry or other signal processing circuitry for pre-amplifying or otherwise processing the electrical signal input. The violin shoulder rest is configured to mount a positionable microphone subassembly adjacent a respective signal input connector.

Abstract: The invention provides a monolithic Y-bit resistive-ladder type digital-to-analog converter (DAC) having a unity gain inverting operational amplifier as an input buffer to the resistive ladder segment of the DAC. The reference voltage is applied to the input buffer amplifier. Optional bipolar operation is provided by applying a non-inverted reference voltage to the output of the resistive ladder segment of the DAC through a scaled resistance. Analog ground current cancellation is provided by a secondary X-bit R-2R ladder (where X Y) with the non-inverted reference voltage applied to it. The secondary bit ladder is switched in parallel with the top X bits of the main ladder, thereby supplying or sinking roughly the same amount of current as the X most significant bits of the main resistive ladder, but with opposite sense.

Abstract: A circuit for controlling the circuit thresholds on an MOS integrated circuit takes advantage of the fact that all MOS devices of a particular type on the same chip have nearly identical characteristics. The circuit thresholds are varied by applying a control voltage to the back gate of an MOS device in each stage to be controlled. The control voltage is generated in a reference stage which utilizes a feedback loop to servo the back gate voltage of an MOS transistor in the loop. A reference voltage equal to the desired circuit threshold votlage is applied to the input of the reference stage. The reference voltage and the reference stage output are applied to an amplifier in the feedback loop. The amplifier applies to the back gate of the MOS transistor in the reference stage a control voltage that tends to equalize or establish a desired offset between the reference voltage and the reference stage output.