Abstract: The range of a threshold detection laser range finder is increased by adding a low cost Analog-to-Digital converter and sampling a portion of a reflected laser pulse. The slope of the sampled reflected laser pulse is calculated and the shape of the reflected laser pulse is inferred from known shapes. The center point of the inferred shape is approximated using a lookup table, and a correction value is calculated based on the center point of the inferred shape and the sampled portion. The correction value is applied to an uncorrected range estimate to arrive at an accurate estimate of the range of the object of interest.

Abstract: The range of a threshold detection laser range finder is increased by adding a low cost Analog-to-Digital converter and sampling a portion of a reflected laser pulse. The slope of the sampled reflected laser pulse is calculated and the shape of the reflected laser pulse is inferred from known shapes. The center point of the inferred shape is approximated using a lookup table, and a correction value is calculated based on the center point of the inferred shape and the sampled portion. The correction value is applied to an uncorrected range estimate to arrive at an accurate estimate of the range of the object of interest.

Abstract: A Miniature Remote Control System (10) that overcomes the problems encountered by previous remote control devices is disclosed. The present invention uses a remote emitter (12) which integrates a radio transmitter circuit (60) in a small housing (34) that plugs into an existing lighter receptacle (28) in a vehicle (V). When pushed down, the remote emitter (12) transmits a coded serial pulse train (16) to a remote receiver (14) up to 200 feet away. The pulse train (16) has a unique code (20) (one of 19,683) on a 380 MHz carrier frequency. The remote receiver (14) processes the pulse train (16), and extracts the serial transmitter code (20). The transmitter code (20) is then compared to the preset receiver code (22), and, if a match is found, a relay (104) is triggered. When activated, the relay (104) can be used to operate external devices (ED), including garage doors (GD), security gates (SG), burglar alarms (SA), exterior lights (EL) or interior lights (IL).

Abstract: Safety discharge circuit and method, capable of protecting workers from electric shocks during maintenance of high voltage electrical systems. A high voltage electrical system is placed inside a grounded box having a cover, releasably connected to the box. The circuit uses an electronic device adapted to sense the removal of the cover from the box and disable the high voltage electrical system. The electronic device is connected to the cover at its input and to the high voltage electrical system at its output, and is preferably a semiconductor controlled rectifier having a gate at its input. The semiconductor controlled rectifier is in a reverse blocking state when the cover is connected to the box, and is latched in a forward conducting state when the cover is removed from the box. The connection from the gate of the semiconductor controlled rectifier to the cover is made through mounting screws, which hold the high voltage electrical system connected to the cover.

Abstract: A Computer Controlled Modular Power Supply for Precision Welding (10) that overcomes the problems encountered by previous power supplies is disclosed. A preferred embodiment of the invention includes an enclosure (100) which holds a Computer Control Module (400), a Welding Power Module (500) and an Electrical Power Module (600). These modules are removable, interchangeable and may be used in any combination. The Computer Control Module (400) includes a microprocessor (406) which is programmed using a color LCD display with a touch screen (300) mounted on one side of the enclosure. In a preferred embodiment of the invention, an 80486 chip is used to run a Microsoft.TM. Windows.TM. Operating System and proprietary, user-friendly software developed by Creative Pathways, Inc. of Torrance, Calif. that controls welding operations. The Welding Power Module (500) includes four removable drawers (502) which each contain an individual power unit.

Abstract: An improved circuit and method of making precise time of arrival measurements on optical pulse data of relatively varying widths. The invention provides an analog input pulse representing received optical pulse data, along with a delayed version of the analog input pulse. The time of delay is set such that the original analog pulse and the delayed analog pulse cross each other at a predetermined point. This cross-over consistently occurs at the same point on the signal independent of the size or shape of the analog pulse. Preferably, the cross-over occurs at approximately 70% of the analog pulse amplitude. The cross-over point between the original pulse and the delayed pulse triggers the generation of the leading edge of a time of arrival pulse.

Abstract: Laser range finder circuitry including an avalanche photodiode detector, a capacitor for storing a detector bias voltage, and a transimpedance amplifier for amplifying the detector signal. The capacitor is charged in response to a first control signal by a circuit employing first and second field effect transistors and is discharged in response to a second control signal by a circuit employing a third field effect transistor. An overload protection circuit including a single diode is provided to accommodate excessive charge created by backscatter upon initial laser firing. A temperature sensor is further provided to develop a temperature signal which may be monitored to adjust the detector bias voltage and other parameters so as to permit use of an associated laser range finder over a wide range of temperatures.

Abstract: A laser range finder receiver for detecting a return pulse and providing an output signal indicative thereof and a single-chip microcontroller for controlling receiver operation and, in particular, for automatically recalibrating the receiver. The receiver is responsive to up and down current control signals from the microcontroller to adjust the bias of an APD photodetector. An offset voltage and receiver false alarm rate are monitored with no light on the photodetector while a calibration voltage is adjusted to recalibrate the receiver. The microcontroller further monitors photodetector temperature via a temperature sensor, and can perform APD bias adjustment and receiver recalibration in response to temperature changes, providing operation over a wide temperature range.

Abstract: A high-speed data register for storing a series of data values received at a high-speed clock rate and including a first set of pipelined latches and a second set of pipelined latches. Control circuitry loads the received data values alternately into said first set of latches and said second set of latches from an input or "last" register, which stores the last data value received by the data register. Data values thus enter the last register at the high-speed clock rate but are loaded into each of the first and second set of pipelined latches at one-half that rate.

Abstract: A laser range finder including a receiver for detecting a return pulse and providing an output signal indicative thereof, a single integrated circuit digital range counter chip connected to receive the output signal from the receiver, a power supply unit for powering the receiver and range counter chip, and a single-chip microcontroller for selectively sequencing application of power to the receiver and to the range counter chip, for controlling laser firing, and for automatically recalibrating the receiver.

Abstract: A power management system for a laser range finder including a microcontroller which controls the supply of power by a series of linear regulators to analog electronics and digital electronics such that the respective electronics units are powered only during intervals when they require power during operation of the laser range finder. The linear regulators and a laser firing pulse generator circuit are powered by simplified DC/DC converter circuitry which is, in turn, supplied with power by a solid state front end circuit subject to control by the microcontroller and which includes first, second, and third transistors providing reverse voltage protection, overvoltage protection, and reduced power consumption.

Abstract: A high intensity discharge light source that uses a pseudo-random sequence generator to modulate an RF drive signal, and reduce electromagnetic interference (EMI) produced by the light source. The light source includes a high intensity RF discharge lamp, control and RF drive electronics that are coupled between a power source and the lamp. The control and drive electronics include an electromagnetic interference filter, and a regulator that outputs a bias voltage. The drive electronics provide RF power to the lamp, and includes an oscillator, a mixer/modulator, an amplifier, and an impedance matching network. The control circuit includes a pseudo-random sequence generator that generates a pseudo-random sequence of pulses to modulate the mixer/modulator and thus the output of the oscillator to thereby reduce the EMI spectral density generated in driving the RF discharge lamp.

Abstract: A power beam tube is biased to supply a constant current to an EO crystal used as part of a frequency modulation circuit for FM laser radar. Integration of the constant current by the EO crystal's capacitance generates the desired ramp voltage waveform. A correction current is easily added to the circuit. The circuit effectively removes the EO crystal driver circuitry from the control loop, increasing the speed of the frequency modulator loop about ten times.

Abstract: A pulse compression signal processor (10) for a laser radar system which utilizes substantially identical negative slope SAW matched filters (30,44) for compressing both the up and down chirps of a bi-directional echo signal (14). The signal processor (10) receives the echo (14) and splits it into two signals (16, 18) for processing by separate negative slope SAW matched filters (30, 44).

Abstract: A closed loop frequency control system for maintaining accurate linearity in the transmitted signal (60) in a linear frequency modulated (LFM) chirped laser radar system. A correction signal (50), derived from an output pulse monitor is summed with the modulation waveform (18) to correct non-linearities in real time.

Abstract: Received expanded radar pulses pass through a surface acoustic wave (SAW) weighted filter (64) for sidelobe suppression, and then into a SAW tapped delay line (66). The pulses appear at the taps (66a,66b,66c) of the delay line (66) coarsely aligned in time, pass through individual SAW matched filters (68,84,86,88) for compression and envelope detectors (70,90,92,94) for demodulation, and then into a summer (74) for post detection integration. Individual frequency shifters (78,80,82) are provided between the delay line taps (66a,66b,66c) and the matched filters (84,86,88) for shifting the center frequencies of the pulses and thereby the propagation delays through the matched filters (84,86,88) to provide fine alignment of the pulses in time. The delays through the individual delay line taps (66a,66b,66c) and the frequency shifts of the frequency shifters (78,80,82) are adjustable "on the fly" to compensate for variation of pulse repetition rate (PRF) and interpulse jitter.

Abstract: An optical backscatter filter (10) for use with continuous wave laser radar systems. The filter removes undesired frequency components corresponding to optical backscatter from a received input signal (12) to extract a desired return signal (32) associated with a target. The received signal (32) is processed optically, requiring only an electronic notch filter (24) and one electronic mixer (30) to finally extract the desired return signal (32).

Abstract: A laser radar detection system (10) is provided for detecting targets located within a detection field and discriminating between unresolved and resolved detected objects (32,34). The detection system (10) employs a laser radar sensor (12) for transmitting a frequency modulated optical transmit signal (22) which scans a desires field and receiving a return signal (24) from objects located therein. The laser radar sensor (12) includes a photo mixer (20) for providing the difference between the return signal (24) and a local oscillator (LO) signal (26) derived from the transmit signal (22). A processor (14) is employed for receiving the difference signal and provides a fourier transform thereof to thereby provide a power spectrum in the frequency domain. The processor (14) analyzes the power spectrum to determine whether the transformed signal contains side lobes (40) and is therefore clutter or does not contain side lobes (40) and therefore indicates the detection of an unresolved object (32).

Abstract: A phase-locked-loop frequency synthesizer (18) normally applies a radio frequency (RF) drive signal (DRIVE) to a CO.sub.2 waveguide laser (10) at a first frequency which is optimal for continuous laser operation. For lighting the laser (10), a voltage-controlled oscillator (26) of the synthesizer (18) is forced to sweep the frequency of the drive signal (DRIVE) downwardly from a second frequency which is higher than the first frequency, through an intermediate third frequency which is optimal for laser lighting, to the first frequency. The laser (10) is lit during the downward sweep through the third frequency, and thereafter maintained at the first frequency for continuous operation.