Abstract: A remote control is used to extend the recording time of a recording device (typically a camcorder (20)). The remote control periodically commands the camcorder (20) to record for a relatively short period of time and then stop recording. In this way, the camcorder (20) is caused to record in a time-lapse fashion. Also, the remote control is used to disable all recording for periods of time when it is known that an event of interest will not occur during these periods. Provisions are made for extending both the recording tape time and the camcorder battery (34) life.

Abstract: An apparatus and method are provided for use in tracing a cable; the apparatus and method allows a cable to be identified at any point along its length. The apparatus includes a transmitter for applying a unique waveform to a cable of interest, a line terminator for forming a cable loop through which current can flow, and a detector which is capable of detecting both voltage (electric field) and current (magnetic field). The unique waveform induces both a magnetic and an electric field in specifically identifiable patterns.

Abstract: An apparatus and method is disclosed for the location of faults occurring within transmission systems. The disclosed apparatus and method allows a user to adjust the center frequency of a pulse output by a standard narrow bandwidth time domain reflectometer, without altering the bandwidth of the output pulse. As a result, the detection of faults occurring at a wide range of frequencies is enabled--while the cost associated with widening the bandwidth of the transmitted pulse is not incurred. Moreover, due to the narrower bandwidth, efficient fault detection is achieved as well for high frequency systems as for low frequency systems.

Abstract: A sensor for permitting a signal carried on a tested conductor to be either inductive or capacitively coupled, in non intrusive manner, onto first or second output conductors includes a partially hollow material with high magnetic permeability wound by a first output conductor for permitting a signal carried on a tested conductor to be inductively coupled onto the first output conductor and a conductive material inserted partially within the hollow material and connected to the second output conductor for permitting a signal carried on a tested conductor to be capacitively coupled onto the second output conductor.

Abstract: An improved method and apparatus for detecting signals on a twisted pair of transmission lines includes a sensor for nonintrusively coupling a portion of the signal to the apparatus. A filter is coupled to the sensor and filters unwanted frequencies from the signal. The signal is then amplified and optionally passed to an identification circuit which identifies the presence of high and low frequency signals. The signal is rectified creating a DC signal proportional to the detected signal's strength. An audio tone proportional to signal strength is generated and the tone is amplified and output.

Abstract: An improved method and apparatus for achieving ping-pong communication over a single channel comprises a circuit (located at each communication station) which adjusts the transmission frequencies of two or more communicating stations such that each communicating station is transmitting at the same frequency as the other communicating stations. Additionally, the circuit provides a time delay between data receipt and data transmission at a given station such that data is not transmitted from the given station when data is being received by the given station. In the preferred embodiment cross coupled phase-lock loops are employed and the delay provided is such that a data pulse is transmitted half way between the receipt of two consecutive data pulses.

Abstract: An apparatus and method are provided for use in tracing transmission lines from a first location to a second location. The apparatus includes a signal generator, a timer/controller, a switching controller and a number of switches. In operation the switches are connected to transmission lines to be traced. The signal generator produces one or more unique signals. A unique signal pattern is applied to each transmission line by selectively opening and closing the switches connected to each transmission line, thereby allowing each transmission line to be traced from a first location to a second location by detection of the corresponding unique signal pattern.

Abstract: An improved method and apparatus for detecting signals on a twisted pair of transmission lines includes a sensor for nonintrusively coupling a portion of the signal to the apparatus. A filter is coupled to the sensor and filters unwanted frequencies from the signal. The signal is then amplified and optionally passed to an identification circuit which identifies the presence of high and low frequency signals. The signal is rectified creating a DC signal proportional to the detected signal's strength. An audio tone proportional to signal strength is generated and the tone is amplified and output.

Abstract: A laser cavity (12) subject to temperature induced effective length change greater than the length of a single power signature cycle of the laser is automatically stabilized by a combined digital arrangement for finding and locking on a selected signature peak corresponding to an optimum laser cavity length, and then digitally tracking such optimum length so as to stabilize operation at such peak. A piezoelectric crystal transducer (26) mounts one of the cavity mirrors (24) and is driven to change effective cavity length, first in an acquire mode, and then in a tracking mode. In acquire mode, voltage on the piezoelectric crystal transducer (26) is increased in a step wise linear fashion from near zero to a near maximum displacement of the crystal. A gain curve peak (33,34,35) is identified by sampling output power (30) of the laser, and storing the maximum value of sampled power, together with a peak transducer driving voltage at which such power maximum occurs.

Abstract: A laser transmitter utilizes optical far field combination of two independent lasers (80,90) and variation of RF exciting power (86) to one (80) to produce sufficient frequency modulation. Two bores (122,124) within the same dielectric body (120) are provided with two independent sets of electrodes (134,135, 138,139) and two independent RF power sources (150,152). The lasers are operated at different frequencies and the beams transmitted in parallel adjacent paths to provide a combined far field optical beam component at the beat frequency of the two lasers. Variation of the frequency of one of the lasers provides frequency modulation of the far field beat frequency, enabling reception and demodulation of the modulated beam without use of a local oscillator laser at the receiver. The transmitter may also be used in a laser radar.

Abstract: A laser array having effectively separate oscillation regions 70,72,74 that are locked in phase is formed with a ceramic body 60,64 having a single, unpartitioned and relatively wide cavity area 62. Effectively isolated separate side by side laser oscillation regions 70,72,74 within the cavity are provided by use of common reflector optics 66,68 on the respective ends of the common cavity, 62 with one of the end optic arrangements comprising a common substrate 100 provided with several separate areas 102,104,106 of high reflectivity, mutually spaced from one another by areas of relatively low reflectivity. Individual control of the several separate regions of laser energy oscillations is provided by employing a separate pair of exciting electrodes 76,78,82,84,88,90 for each such region and applying separate RF exciting signals to the separate pairs respectively.

Abstract: A radio frequency excited carbon dioxide laser (50) is stabilized by sensing (66) variation in output power to generate a feedback signal (68,78 ) that is employed to vary amplitude of the radio frequency exciting signal from a power source (62). Frequency modulation of the laser output is achieved by varying the amplitude of the radio frequency signal from a power source (62) in response to a frequency modulating control signal from a modulation source (74). Both stabilization and frequency modulation are accomplished by combining the sensed power feedback signal with the frequency modulation control signal in a summing circuit (70) and employing the combined signal to vary magnitude of the radio frequency exciting signal.