Abstract: A system for providing intermittent communication while preserving a sterile area is provided. Sterility is preserved because the user can switch between transmitting and receiving mode without needing to touch a physical button, switch, or dial. The system is particularly valuable to doctors or dentists performing procedures. The system includes a two-way communication device coupled with a sensor, the sensor being capable of detecting the presence of an object, generally the user's hand or an instrumentality of the user, located closer than a predetermined distance from the sensor in a predetermined direction relative to the sensor. Upon such detection, the communication device is switched from receiving to tranmitting mode and remains in transmitting mode until a predetermined amount of time has elapsed since the object has ceased to be located within the predetermined distance in the predetermined direction of the sensor.

Abstract: A system for providing intermittent communication while preserving a sterile area is provided. Sterility is preserved because the user can switch between transmitting and receiving mode without needing to touch a physical button, switch, or dial. The system is particularly valuable to doctors or dentists performing procedures. The system includes a two-way communication device coupled with a sensor, the sensor being capable of detecting the presence of an object, generally the user's hand or an instrumentality of the user, located closer than a predetermined distance from the sensor in a predetermined direction relative to the sensor. Upon such detection, the communication device is switched from receiving to tranmitting mode and remains in transmitting mode until a predetermined amount of time has elapsed since the object has ceased to be located within the predetermined distance in the predetermined direction of the sensor.

Abstract: A thermal attach and detach method and system for surface-mounted components (SMCs) employs a planar-heater which generates heat in response to an electrical current. The heater's resistance varies with its temperature, and the resistance is read to determine heater and SMC temperature. A means of gripping an SMC is provided such that the device's I/O contacts are heated by thermal conduction from the planar-heater through and/or along the SMC's side-walls. An electrical current is provided to the planar-heater such that heat sufficient to attach/detach the I/O contacts to or from a PCB is generated. The method enables the gripping, heating, resistance monitoring and SMC temperature measuring to occur simultaneously. Several means of gripping an SMC are described, including vacuum, mechanical, adhesive and magnetic. A method which employs a heating element to heat a substrate on which SMCs may be mounted is also described.

Abstract: A controller for controlling the intensity of an electroluminescent display is disclosed. The controller controls a number of skipped cycles in a cycle set of an applied waveform to the electroluminescent display to vary the average duty cycle, and thereby adjust the intensity of the electroluminescent display. The controller is further configured to adjust the intensity of individual channels within the electroluminescent display to provide compensation for display aging, color variation, as well as for varying intensity for various operating modes.

Abstract: An apparatus for automatically controlling the flow of fluid in an inlet conduit that provides the water supply for a home or building so as to prevent water damage due to a failure in the water system when unattended. The apparatus comprises a power circuit for supplying a low voltage DC power output which is connectable to a standard AC power source and includes an internal battery which operates in case of AC power failure. A flow sensor and a shutoff valve are connected in the inlet conduit. A control circuit which can be preset for different operational modes, receives and processes flow status signals from the flow sensor and provides output signals that control the shutoff valve, so that if continuous flow is detected in the conduit for a time period exceeding a preselected time, the shutoff valve will automatically close.

Abstract: A high speed hand held polyphase motor and a control system therefor is disclosed. The motor is of the induction type, designed for use in oral surgery and the like. The control system includes a bridge type inverter having a separate pair of solid state switching devices such as transistors connected in a bridge configuration across a pair of direct current power supply conductors for each phase winding of the motor. A switch control circuit is connected between the solid state switches and a variable frequency clock signal generator for turning the switches of each pair on and off in a given phase sequence to provide three phase current for the motor windings. The speed of the motor is proportional to the clock signal frequency. A voltage regulating circuit is connected between the power supply conductors and a source of direct current voltage to supply a direct current voltage across the supply conductors which varies in accordance with the clock signal frequency over a pre-established range.