Abstract: A cellular base station that includes a baseband unit, at least one programmable power supply and a communication interface is provided. The baseband unit is in communication with a backhaul communication system and a radio. The at least one programmable power supply is configured to provide power to the radio through a communication circuit. The communication interface is in communication with the programmable power supply. The communication interface is configured to provide communications between the programmable power supply and a remote location regarding the communication circuit.

Abstract: A device for use on a back or seat of a chair to provide an indicia that such chair is in use when a person is not seated in the chair. The device includes an elongated foldable web having a first and second end, the length of such foldable web being sufficient to wrap around the width of the seat or back of the chair. Preferably, an adjustable attachment is provided on at least one end of the foldable web for adjustably attaching such one end to the other end of the foldable web. The attachment is a VELCRO type hook and pile attachment. The foldable web may also include indicia removably attached to the foldable web, e.g., a business card, such indicia indicating that the seat is reserved. The foldable web may be securely wrapped around the back or seat of a chair to reserve the chair when it is not in use. In another embodiment, the device is a continuous elastic elongated foldable web, the length of such foldable web being sufficient to tightly wrap around the width of the seat or back of the chair.

Abstract: A coplanar antenna system having a single-coil loop antenna provides both transmit and receive functions. The antenna operates in a tuned mode during transmitting and an untuned mode during receiving. Dead zone and transformer effect problems are virtually eliminated. The transmitter is highly efficient and the receiver is impulse noise immune.

Abstract: An article surveillance system includes a power line activated inductive magnetic field generator having an on duty cycle portion considerably less than 50%. A transformerless AC power line to DC converter and switching circuitry are connected to a series resonant circuit including a coil for deriving the AC inductive magnetic field. During on duty cycle portions, the switches are activated and connected to the series resonant circuit and the power supply to cause resonant current to flow in the series circuit at an activation frequency for the switches, causing the coil to generate the magnetic field at the activation frequency.

Abstract: An inductive magnetic field article surveillance system includes a generator for a first inductive magnetic field having a predetermined frequency. The articles carry a structure which responds to the first magnetic field to derive a second inductive magnetic field having a predetermined frequency; the second field occurs immediately after expiration of the first magnetic field. A receiver for the second magnetic field responds to the predetermined frequency of the second magnetic field to indicate the presence of an article between the generator and receiver, if the frequency subsists for at least a predetermined time interval. The generator for the first magnetic field includes a tuned transmitting coil arrangement, while the receiver includes an untuned receiver coil arrangement.

Abstract: An article surveillance system includes a structure responsive to a first pulsed inductive magnetic field, periodically derived by a power line activated generator. The structure derives a second pulsed inductive magnetic field having a predetermined occurrence time relative to the occurrence time of the first magnetic field. A receiver for the second magnetic field is power line activated. The occurrence time of the first magnetic field and the activation time of the receiver to be responsive to the second magnetic field are synchronized. The synchronization of the transmitter and receiver is provided by separate zero crossing detectors for the power lines respectively activating the transmitter and receiver. The power lines activating the transmitter and receiver are likely to have zero crossings at different predetermined time positions because they are likely to be across two different phases of a three-phase power line.

Abstract: An inductive magnetic field article surveillance system includes a generator for a first magnetic field. Articles to be monitored include a structure responsive to the first magnetic field for deriving a second inductive magnetic field having a predetermined frequency. An inductive magnetic field receiver responsive to the second magnetic field includes a receiver coil arrangement for deriving a signal that is a replica of variations of the second magnetic field. Processing circuitry responds to the receiver coil arrangement to derive an indication of the presence of the structure. The receiver coil arrangement includes first and second coils likely to have different responses to the second magnetic field. Only one of the first and second coils is connected to the processing circuitry at a time, as a function of which coil is supplying a signal at the predetermined frequency of the second field to the processing circuitry for at least a predetermined time interval.

Abstract: An article surveillance system includes a generator of a first inductive magneticc field having on and off duty cycle portions. The generator derives the first magnetic field at a predetermined AC frequency during the on duty cycle portions. The articles to be detected includes a structure which responds to the predetermined frequency of the first magnetic field to derive a second inductive magnetic field at a predetermined frequency. The second field is derived as a pulsed wave having a starting time at the expiration of each on-duty cycle portion and a predetermined carrier frequency. A receiver for the predetermined frequency of the second inductive magnetic field derives first and second different responses while an article including the structure is and is not in a detection region magnetically coupled to the receiver and transmitter.

Abstract: A coplanar antenna system has an interrogating means adapted to generate time varying magnetic field components within a region proximate thereto and a receiving means adapted to detect magnetic field components within a region proximate to the antenna system. The interrogating means has a plurality of coils configured such that the components thereof have near zero net resultant magnetic field. At least one coil of the receiving means is configured to detect components thereof having a preselected net resultant magnetic field.

Abstract: A drill sight for visually estimating the angle at which an electric hand drill is oriented relative to the surface drilled, the drill sight is mounted to the top of the electric drill and has a tubular casing with a hollow bore with internal wall markings and with a cross hair at one opening. By projecting a line of sight normal to the surface drilled and through the cross hair to a selected wall marking, the orientation of the drill can be determined.