Abstract: The operation of software carrying out a computer program is monitored for determining which blocks of code are being run and which are inactive. Each block of code being monitored has a software probe inserted at the beginning of the block for detection and identification purposes. In one embodiment, the software probe inserted in the block of code is automatically increment by 1 to indicate that the block has been accessed. The extent of use, or activity, of each block of code is recorded and presented in graphic form on a video display. In a first mode of operation, the times at which a selected block of code is accessed within a given time period is displayed along a horizontal axis and the number of times of access at each time it occurs is represented along a vertical axis in bar graph form.

Abstract: A ground fault interrupter, operable in a measurement state, is employed with a DC circuit having a DC power source and a load. The DC source supplies DC current to the load along a supply current path and receives DC current from the load along a return current path. The ground fault interrupter comprises a first resistance in series with the supply current path, a second resistance in series with the return current path, and a current interrupter disposed in series with one of the current paths. The current interruptor interrupts the one of the current paths in response to actuation of the current interrupter. The ground fault interrupter further includes a measurement unit for measuring voltage drops across the respective first and second resistances during the measurement state, obtaining a measurement value using a difference between the voltage drops, and comparing the measurement value to a predetermined threshold.

Abstract: A communication system includes a distribution center which collects and processes signals from one or more program sources, and distributes these signals in compressed format to one or more airline terminals, each terminal in communication with one or more parked aircraft. An airline issues a program request identifying certain ones of the program sources, and sends this request to the distribution center where a composite signal is prepared including representations of the program source signals and the program request. The composite signal is transmitted to receiver units at subscriber airline terminals of airports where individual program orders are stored and subsequently distributed to the appropriate aircraft for subsequent in-flight playback of the programs.

Abstract: A battery powered portable acoustic transmitter comprises a plurality of single-pole, momentary contact switches, a type 555 pulse producing integrated circuit chip, and an electroacoustic transducer and matching tuning coil. An RC timing circuit includes a plurality of resistors selectively connectable in the timing circuit by the switches to vary the pulse output frequency. A transistor output circuit amplifies the pulses for driving the transducer. A plurality of diodes supply power to the chip and the transistor output circuit whenever a switch is activated. The integrated circuit chip, resistors, diodes and transistor are part of an active thick film circuit.

Abstract: An electronic remote control transmitter employs a two transistor cascade oscillator having positive and negative feedback loops. The oscillator voltage is supplied through a switch assembly containing a plurality of momentary contact switches to a pair of voltage dividers supplying signal voltages in predetermined ratios to a two branch circuit in the negative feedback loop. One branch contains an inductor and the second branch a capacitor. Closure of any switch completes the DC circuits for the transistors. Signal voltage is supplied to the branches to produce a minimum amplitude, zero phase shift condition which establishes oscillation at that predetermined frequency. The output of the oscillator is amplified by a third transistor and supplied to an ultrasonic transducer for generating acoustical control signals.

Abstract: A battery powered portable acoustic transmitter comprises a plurality of single-pole, momentary contact switches, a type 555 pulse producing integrated circuit chip, and an electroacoustic transducer and matching tuning coil. An RC timing circuit includes a plurality of resistors selectively connectable in the timing circuit by the switches to vary the pulse output frequency. A transistor output circuit amplifies the pulses for driving the transducer. A plurality of diodes supply power to the chip and the transistor output circuit whenever a switch is activated. The integrated circuit chip, resistors, diodes and transistor are part of an active thick film circuit.

Abstract: A wireless remote control system has a transducer coupled to a sampling first counter for counting the frequency of incoming signals. A portion of the count distinguishes among various control signal frequencies and is supplied to a memory and a comparator. A second counter counts the number of identical comparisons of present and immediately preceding measurements, and is reset when a non-identical comparison is detected. The memory supplies the stored portion of the count to a decoder which is disabled by the second counter until a predetermined number of identical frequency comparisons have been determined, which provides noise immunity. The decoder is coupled to utilization means to activate the control function corresponding to the frequency of the control signal.

Abstract: A broadcast receiver has a reversible binary counter having its output coupled to a digital-to-analog converter which translates the counter's binary coded output signal to a control voltage and applies it to a voltage controllable circuit means. A local source of clock pulses is selectively coupled to the counter by a pair of operator actuated switches to preferentially alter the counter output signal. The binary coded counter output signals are coupled to a non-volatile memory by read/write means for storage during periods of receiver deactivation and reimposed on the counter during subsequent activation of the receiver. Receiver activation and deactivation transitions are detected by voltage sensing means which are coupled to the read/write means and are responsive to changes in the receiver operating potential. Preset means comprising a non-volatile, non-erasable memory and selector switches permit resetting the counter to a predetermined binary data configuration.