Abstract: A battery pack connection system includes a first battery pack, a second battery pack, and a battery receptacle. Each of the first and second battery packs includes a first guide slot, a second guide slot, and an electrical connector slot. The second battery pack has a power capacity and a width greater than the first battery pack. The battery receptacle defines an elongate passage sized and shaped to separately receive each of the first and second battery packs therein. The battery receptacle includes an electrical connector rail, a first guide rail sized and shaped to cooperatively engage the first guide slot of each of the first and second battery packs, and a second guide rail sized and shaped to cooperatively engage the second guide slot of each of the first and second battery packs.

Abstract: Power tools such as cutting saws with rotary powered blades are described. Also described are various accessories for tools used with cylindrical workpieces such as pipes are described. The accessories include a clamp and saw joint assembly, various quick connection assemblies between a saw and a clamping system, a plunge guide assembly, a latch plate assembly, an interlock switch, a blade guard system, and a chip management system or chip deflector. Also described are related methods of use.

Abstract: Power tools such as cutting saws with rotary powered blades are described. Also described are various accessories for tools used with cylindrical workpieces such as pipes are described. The accessories include a clamp and saw joint assembly, various quick connection assemblies between a saw and a clamping system, a plunge guide assembly, a latch plate assembly, an interlock switch, a blade guard system, and a chip management system or chip deflector. Also described are related methods of use.

Abstract: A plasma generator system for reducing the effects of impedance mismatch. The system has a variable frequency source having an output for emitting an RF signal. A plasma chamber has an input for receiving the RF signal. The variable frequency source modulates at least one of the frequency and phase of the RF signal to improve the system tolerance of impedance mismatches between the output of the variable frequency source and the input of the plasma chamber.

Abstract: A system for communicating signals and data without the need for continuous telephone lines is described. This system provides a base unit connected to incoming signals, such as cable, satellite, PCS, cellular, fiber optics, XDSL, ISDN, etc, one or more extension units connected to the users telephone or electronics equipment and a communication link between the base unit and the one or more extension units. The preferred communication link employs a combination of an A/C power line carrier and a wireless RF channel. This system provides for the communication signals from a variety of sources through out a building or office without requiring either dedicated telephone lines or the availability of AC power outlets near the user's telephone extension equipment. This invention, in its preferred embodiments, is specifically adapted to meet the technical requirements of A/C power line communications, while taking advantage of RF communication within buildings or facilities.

Abstract: A method and system which detects failures in communication between a base unit and an extension unit in a wireless communication system and which resets the system upon detecting such failures is described. A wireless communication system in this invention can use an RF over the air communication channel or an AC power line communication channel. In this method and system failures in the extension unit are detected and the base unit is reset, thereby permitting further use of the telephone communication link. A variety of embodiments are disclosed, including: transmitting a low frequency signal from the extension unit; transmitting a high frequency signal from the extension unit; periodically transmitting a status command signal from the extension unit; and detecting the signal strength of the transmitted signal from the extension unit in the base unit.

Abstract: A system for communicating signals between a transmitter and a receiver using digital modulation techniques is provided. This invention is particularly adapted to meet the requirements of power line communication. In one preferred embodiment of this invention the modulation technique is differential binary phase shift key modulation. This system provides a low cost, simple delay and multiply process for the modulation and demodulation of data. This system lends itself to an ASIC implementation, thereby further reducing the cost of the system while improving the reliability of the system in a noisy environment.

Abstract: A system and method for the automatic detection and matching of power line impedance which makes use of level detection and source impedance circuits in electronic communication with the existing circuitry of a power line communication devices are disclosed. This invention uses modified power line communication device circuitry to sense the impedance of the power line and to correct its impedance to match the impedance of the power line. By automatically sensing and adjusting the source impedance of the power line jack this invention maximizes power transfer to and from the power line, reduces radiated power as well as the power line reflection coefficient.

Abstract: A system and method for detecting power line null frequencies and for adjusting the transmit frequency and transmit power to maximize the reliability and efficiency of the AC power line transmission link is described. This invention uses a programmable logic device in the transmitter, which transmits multiple frequencies to a receiver. The receiver detects and records the bit error rate and/or the received noise per frequency and communicates this information to the transmitter. When all desired frequencies have been transmitted and tested, the optimal frequency is identified or selected. Generally, the optimal frequency is the frequency requiring the lowest transmit power while maintaining an acceptable bit error rate or an acceptable noise level.

Abstract: A wireless telephone jack that uses the 49 MHz frequency band as allowed by the FCC (47 CFR 15.233). This jack supports both voice and data communication and operates as a convenient means for providing telephone device communications in locations where telephone wiring is limited or unavailable. A base station is provided to connect to the telephone lines, or a central office, which has an RF transmitter and receiver for communicating with a provided extension unit, which also has an RF transmitter and receiver for communicating with the base station. This invention is designed to work with standard telephone communication signals and standard telephone equipment.

Abstract: A method and system for the reception, conversion and distribution of wireless signals over AC power lines to one or more telephone communication devices within a building, office or complex is disclosed. This invention specifically provides for the reception of PCS, cellular and/or satellite communication signals, by receiving the wireless signal and providing an interface to standard generally available telephone equipment. By making use of the power line carrier channel, this invention provides for the reception of the wireless signals upon telephone equipment that is located in the building or complex in locations remote from standard telephone wiring. Moreover, by distributing such received wireless signals over the power line a number of telephone devices can be used to receive the distributed signals.

Abstract: A method and system for the reception, conversion and distribution of wireless communication signals received from such communication devices as PCS, Cellular, and Satellite over AC power lines commonly found within a building, office, home or other structure is disclosed. This invention specifically provides for the distribution of wireless signals in structures where otherwise signal degradation and/or blockage are common. Moreover, this invention takes advantage of the existing AC power lines to create a communication channel avoiding the necessity of rewiring the building or other structure. This invention provides important improvements to the signal coverage and reception of wireless transmitted signals within buildings and other structures and does so in an efficient and cost effective manner.

Abstract: A wireless power line carrier data communication device is provided. The device is specifically adapted to meet the requirements of high-speed modem data transmission, such as is typically required by digital computer networks and similar devices. The device employs an improved power line transmitter power output which reduces the effect of harmonic distortion and also employs a bit-stream sine wave generator with a digital to analog converter to producing a sine wave for the sub-audio carrier signal, which also reduces the effects of harmonic distortion. The device is specifically designed for data transfer over the AC power lines and is compatible with standard AC power signals as well as standard modem equipment and standard telephone connections.

Abstract: A wireless power line carrier voice and data communication device is provided. The device permits a user to connect one or more electronic devices to surge suppress and isolated AC power connections while simultaneously providing a communication channel between telephone equipment, such as telephone extensions, modems and/or facsimile machines, across the AC power lines to a remote telephone connection. This invention prevents the degradation of the voice and/or data signal across the power lines that would otherwise be induced by the AC connected electronic equipment. Furthermore, this invention provides a cost effective, convenient solution to the data processing user who requires access to telephone lines, for voice, data or both, as well as AC power outlets for electronic equipment all from a physical location some distance from a convenient phone connector. The isolation and surge suppression circuitry is designed specifically to address the power line carrier environment.

Abstract: A wireless power line carrier voice and data communication device is provided. The device permits a user to connect a caller identification unit to a telephone extension whose only connection to a telephone line is over an AC power line. The invention provides for appropriate amplification, joining with other audio paths, and transmission while requiring no hardware modifications of the extension unit or the wireless extension jack.

Abstract: A method and system for multiple access telephone communications is described. The system utilizes one or more base units connected to subscriber lines, and multiple extension units in communication with each base unit via building power lines. Secure multiple access coding is used to prevent eavesdropping and interference. Extension units may employ cordless telephone technology. Caller ID information transmitted with incoming telephone signals may be transmitted to extension units via building power lines and displayed on the extension handset or cradle.

Abstract: A spread-spectrum communication system in which the energy output is more smoothly distributed than the length of the pseudo-random code would otherwise indicate. A spread-spectrum communication system in which the code sequence is pseudo-randomly inverted on data-bit boundaries, so that the code sequence appears longer, for energy spreading, than it otherwise would appear.

Abstract: A spread-spectrum communication system in which the energy output is more smoothly distributed than the length of the pseudo-random code would otherwise indicate. A spread-spectrum communication system in which the code sequence is pseudo-randomly inverted on data-bit boundaries, so that the code sequence appears longer, for energy spreading, than it otherwise would appear.

Abstract: A signal detector for receiving a wide band (W) of frequency-hopped signals which channelizes the incoming signals, via filter banks into a plurality (L) of channels. Magnitude squaring circuits in each channel generate a "power" estimate which is compared to a preset threshold value by threshold-quantizer units that produce a positive voltage (=1) if the threshold is exceeded. After summation of all the channels, the direct sequence (DS) signal component and noise component are processed so that a DC voltage is produced if a frequency-hop signal (FH) is present which is greater in value than when the signal is not present. Thus the DC signal indicates whether the FH signal is present or absent.

Abstract: A narrowband parameter estimator circuit is described which can be used to estimate the frequency and the relative power of narrowband interference tones which reside in a wideband information signal. A two-weight adaptive filter with a phase/frequency-lock loop circuit works in conjunction with a stepped synthesizer to lock onto the individual narrowband interference tones. A lock-detect circuit signals a digital logic unit to record the frequency of the stepped synthesizer and to measure the power in the adaptive filter output signal. This same output signal is used to cancel the unwanted tone in the wideband information signal being transmitted.