Abstract: Systems and methods for detecting ground faults in a power transmission circuit powering a load. The system includes a common mode union that is connected to a positive terminal of a power supply and a negative terminal of the power supply. The power supply may be a bifurcated symmetrical power source. A power supply symmetry circuit is connected to the common mode union and a offset threshold comparator circuit is connected to the power supply symmetry circuit. The offset threshold comparator circuit is configured to compare a signal from the power supply symmetry circuit to a threshold voltage value and generate a ground-fault signal indicating a ground fault when the signal from the power supply symmetry circuit exceeds a threshold voltage value. A local load control circuit is connected to the offset threshold comparator circuit and configured to receive a signal from the offset threshold comparator circuit.

Abstract: A durable touch screen assembly including a display screen for projecting images to a viewer; an optically clear, flexible touch sensor through which the images are projected; an optically clear, flexible substrate positioned between the electronic display screen and the flexible touch sensor; a space between the flexible substrate and the electronic display screen sufficient to enable the substrate and the touch sensor to flex; and a durable polycarbonate protective layer at least about 0.01 inch thick attached in front of the touch sensor substantially free of intervening features that would impair visibility.

Abstract: A system for optimizing the transmission of power through multiple conductors from a remote power source to a local communications device including: (a) a controller for the power source and for incrementally increasing the output voltage during a transmission resistance detection protocol; (b) a first voltage detection circuit for detecting a predetermined minimum voltage received by the detection circuit and for placing a load across the conductors when that minimum voltage is received; (c) a second voltage detection circuit for detecting a predetermined maximum voltage received by that detection circuit and for removing the load from across the conductors at that time; (d) voltage and current measuring devices to measure the transmission current and the output voltage of the power source when the predetermined maximum voltage is received; and (e) memory for storing the measured voltage, measured current and the predetermined maximum voltage for use by the controller.

Abstract: Embodiments are described that include a “front end” device located remotely from a local telephone location. The front end filters DC and AC current on a telephone line to separate these signals and passes a DC current through a low resistance Low Pass Filter without traditional resistance or current limiting means. The front end also provides signaling capability isolated from the DC and audio channels by a High Pass Filter. Some embodiments also include a “back end” unit located near a local telephone location. The “back end” unit filters the DC and AC currents into at least two DC current streams. One of the DC current streams provides sufficient current to power a local telephone. The other stream(s) provides current sufficient to power an auxiliary device. The “back end” device may also provide signaling isolated from the DC and audio channels that is complementary to the “front end” signaling.

Abstract: Embodiments are described that include a “front end” device located remotely from a local telephone location. The front end filters DC and AC current on a telephone line to separate these signals and passes a DC current through a low resistance Low Pass Filter without traditional resistance or current limiting means. The front end also provides signaling capability isolated from the DC and audio channels by a High Pass Filter. Some embodiments also include a “back end” unit located near a local telephone location. The “back end” unit filters the DC and AC currents into at least two DC current streams. One of the DC current streams provides sufficient current to power a local telephone. The other stream(s) provides current sufficient to power an auxiliary device. The “back end” device may also provide signaling isolated from the DC and audio channels that is complementary to the “front end” signaling.

Abstract: A process and a system are disclosed for detecting activity, e.g., three way calling, call forwarding, or the like, during a phone call. The process includes, and the system is configured for, establishing the call path between a first party and a second party, adding a reference tone to the call path, observing a reflected tone from the call path, and determining a relationship between the reference tone and the reflected tone. Information relating to the relationship may be reported for further analysis.

Abstract: Embodiments are described that include a “front end” device located remotely from a local telephone location. The front end filters DC and AC current on a telephone line to separate these signals and passes a DC current through a low resistance Low Pass Filter without traditional resistance or current limiting means. The front end also provides signaling capability isolated from the DC and audio channels by a High Pass Filter. Some embodiments also include a “back end” unit located near a local telephone location. The “back end” unit filters the DC and AC currents into at least two DC current streams. One of the DC current streams provides sufficient current to power a local telephone. The other stream(s) provides current sufficient to power an auxiliary device. The “back end” device may also provide signaling isolated from the DC and audio channels that is complementary to the “front end” signaling.

Abstract: Embodiments are described that include a “front end” device located remotely from a local telephone location. The front end filters DC and AC current on a telephone line to separate these signals and passes a DC current through a low resistance Low Pass Filter without traditional resistance or current limiting means. The front end also provides signaling capability isolated from the DC and audio channels by a High Pass Filter. Some embodiments also include a “back end” unit located near a local telephone location. The “back end” unit filters the DC and AC currents into at least two DC current streams. One of the DC current streams provides sufficient current to power a local telephone. The other stream(s) provides current sufficient to power an auxiliary device. The “back end” device may also provide signaling isolated from the DC and audio channels that is complementary to the “front end” signaling.

Abstract: A process and a system are disclosed for detecting activity, e.g., three way calling, call forwarding, or the like, during a phone call. The process includes, and the system is configured for, establishing the call path between a first party and a second party, adding a reference tone to the call path, observing a reflected tone from the call path, and determining a relationship between the reference tone and the reflected tone. Information relating to the relationship may be reported for further analysis.

Abstract: Embodiments are described that include a “front end” device located remotely from a local telephone location. The front end filters DC and AC current on a telephone line to separate these signals and passes a DC current through a low resistance Low Pass Filter without traditional resistance or current limiting means. The front end also provides signaling capability isolated from the DC and audio channels by a High Pass Filter. Some embodiments also include a “back end” unit located near a local telephone location. The “back end” unit filters the DC and AC currents into at least two DC current streams. One of the DC current streams provides sufficient current to power a local telephone. The other stream(s) provides current sufficient to power an auxiliary device. The “back end” device may also provide signaling isolated from the DC and audio channels that is complementary to the “front end” signaling.

Abstract: Methods and apparatus for use in connection with a telecommunication between a local telephone and a remote telephone, which are capable of detecting whether one of the parties to the communication has attempted to initiate a three-way, i.e., conference, call by using a hook-flash signal. The apparatus includes a low pass filter for passing energy having frequencies below about 500 Hz, and an energy detector for detecting a specific electrical energy pulse characteristic of the hook-flash having passed through the low pass filter. The existence of the hook-flash is confirmed by digital signal processing equipment which identifies a rapid drop-off in energy also characteristic of the hook-flash signal. Optionally, the hook-flash may be further confirmed by including software for cooperating with the energy detector to ascertain whether sound has occurred in the telecommunication during a predetermined period following the first hook-flash signal.

Abstract: Methods and apparatus for use in conjunction with a telephone or with equipment in telecommunication with a remote telephone are disclosed. The apparatus provides an indication as to whether a remote party using the remote telephone has performed a specific act causing the generation of a hook flash-type signal which is detected by the apparatus. The apparatus includes a low pass filter for passing energy having frequencies below about 500 Hz, and energy detector for detecting a specific electrical energy pulse having been filtered by the low pass filter and having a predetermined minimum magnitude. The apparatus also includes software for cooperating with the energy detector to detect a specific event(s) occurring on the telephone line during a predetermined maximum time window following the detection of a specific pulse. The detection of the specific event(s) provides an indication as to whether the remote party has performed a specific act such as attempting to initiate a 3-way conference call.

Abstract: This invention relates to an improved fluid pump. The pump is of the type, wherein a reciprocating motor acts in concert with supply and exhaust valves to pump fluid from a source to its destination. In the preferred embodiment, the motor comprises a reciprocating diaphragm and the supply and exhaust valves comprise a single resilient plate with individual valve members formed as cutouts therein. The valve plate is sandwiched between two plates which form the associated porting. The interaction between the various ports on the valve plates results in improved sealing effect for the valves.

Abstract: An automatic tourniquet including a mechanism for inflating and deflating a cuff, a pressure sensing mechanism, and a mechanism for displaying the pressure. The pressure sensing mechanism includes a pressure transducer producing a pair of digital signals, and a mechanism for adjusting the signals so that the pressures at which the transitions between the digital quanta occur for one signal are different from the pressures at which the transitions occur for the other signal. The mechanism for adjusting includes a mechanism for setting the signals to be equal at a selected pressure, and a mechanism for offsetting the signals from each other by a voltage corresponding to one-half a digital quantum. The offset signals are summed by a microprocessor to produce a display with twice the resolution of the individual signals.