Abstract: A metal detector has multiple transmit and receive coils for producing multiple detection fields. In one embodiment, a transmit coil is combined with two receive coils in a configuration that enables the detector to generate two detection fields, one being substantially narrower than the other. The transmit coil is inductively balanced with the receive coils such that the transmit coil induces minimum signals in each of the two receive coils. A metal target lying within a detection field changes the coupling between transit and receive coils and produces signals in the receive coils. The received signals are utilized to identify the target's presence within one or both of the detection fields. The use of two detection fields, substantially different in size, enables the metal detector to search over a broad area for object detection and then narrow the search to more precisely locate the detected object.

Abstract: An improved track and vehicle system are provided for model electric vehicles. The track system includes a number of interconnectable panels having alternate portions of negative and positive polarity conductor strips defined on a top surface thereof. The conductive strips are separated by non-conductive portions. Each of the panels includes electrical and mechanical interlocking devices carried on each side thereof so that any one panel can have additional panels connected on each of its sides. The vehicles include a unique arrangement of contacts carried on a linkage underneath of the vehicle to ensure that the vehicle remains at all times in contact with the conductors, regardless of the direction of movement of the vehicle from the surface of the panels.

Abstract: A metal detector utilizes digital signal processing and a microprocessor to process buffers of information which is received at a periodic rate. Both high and low gain phase quadrature and in-phase signals are provided via a multiplexer to an analog-to-digital converter from a first receive antenna. A second receive antenna provides phase quadrature and in-phase signals also through the multiplexer to the analog-to-digital converter. The received signals are averaged, decimated and low pass filtered to eliminate noise and reduce the quantity of data which must be processed. A threshold (triggering) processing operation is performed to determine whether a valid target signal is present in the data. If not, no further processing is performed. The in-phase and quadrature components are processed using Fourier transforms to select a frequency band which includes the energy for the target signal. The energy in this frequency band is utilized to determine the identification of the target.

Abstract: A metal detector utilizes digital signal processing and a microprocessor to process buffers of information which is received at a periodic ram. Both high and low gain phase quadrature and in-phase signals are provided via a multiplexer to an analog-to-digital converter from a first receive antenna. A second receive antenna provides phase quadrature and in-phase signals also through the multiplexer to the analog-to-digital converter. The received signals are averaged, decimated and low pass filtered to eliminate noise and reduce the quantity of data which must be processed. A threshold (triggering) processing operation is performed to determine whether a valid target signal is present in the dam. If not, no further processing is performed. The in-phase and quadrature components are processed using Fourier transforms to select a frequency band which includes the energy for the target signal. The energy in this frequency band is utilized to determine the identification of the target.

Abstract: An apparatus for holding an IC device for tinning the leads in a wave soldering machine is disclosed. The apparatus utilizes a pair of beveled surfaces, one on each side of the lead to be tinned, to limit the extent of penetration of the lead into the molten solder. The beveled surfaces are made of a material which cannot be wet by the molten solder, therefore, surface tension of the solder will tend to limit penetration of the molten solder into the area defined by the beveled surfaces.

Abstract: There is described herein a method of operating an extruder for thermoplastic material to automatically control the output of the extruder. The extruder includes a kneader screw, a hopper having a feed screw for feeding the thermoplastic material in dry particulate form to the kneader screw and an outlet feed screw for removing the plastic material in molten form from the kneader screw. Each of the screws is operated by a separate electric motor. The method includes monitoring the current of the motor for the kneader screw. Variations in the current indicate variations in the opertion of the kneader screw. Upon any variation in the current of the kneader screw motor, the speed of the hopper feed screw and/or the outlet feed screw is varied to compensate for the variation in the operation of the kneader feed screw and return the current to its original value.

Abstract: An improved apparatus for attaching a record matrix to be replicated by electroforming to the cathode of an electroforming device is provided. The apparatus includes a positioning pin which maintains the record matrix center hole concentric to the cathode and to the replicated grooves and a lock knob which effectively holds the center portion of the record matrix in liquid-tight electrical contact with the cathode.

Abstract: In order to provide an improved seal between matrixes and their replicas, as well as eliminating or substantially reducing the problem of premature separation of the replicas from the matrixes, a circumferential spiral groove of a substantially rectangular configuration is cut into the outermost circumferential area of the matrix. The rectangular spiral groove is cut beyond the portion of the matrix which will be used as the molding surface of the stamper. The rectangular groove is substantially larger than the V-shaped groove of audio records and is much larger than the V-shaped grooves used on high density information discs. Because of the larger size and the substantially rectangular geometric configuration of the grooves, the rectangular spiral groove forms a highly effective seal between the matrix and the replica.

Abstract: It has been found that metal stampers, and more particularly nickel stampers, can be simultaneously hardened and passivated by cathodically treating the stampers in an aqueous bath of a passivation agent.

Abstract: A solid electrolyte film-forming capacitor is provided which includes an electroplated conductive layer over the capacitor. The electroplated layer provides greater resistance to mechanical shock and allows the welding of a cathode termination means to the electroplated layer of the capactior. Also provided is a method for electroplating the capacitor which includes placing an electroprocessed capacitor in an electroplating vessel which contains a plating source and electroplating solution, providing a voltage source and connecting the positive terminal of the voltage source to the anode side of the capacitor and to the plating source and the negative terminal of the voltage source to a conducting layer on the anode body, and then electroplating a layer containing metal over the capacitor.

Abstract: A method is provided for electroplating a solid electrolyte film-forming metal capacitor. The method includes placing an electroprocessed capacitor in an electroplating vessel which contains a plating source and electroplating solution, providing a voltage source and connecting the positive terminal of the voltage source to the anode side of the capacitor and to the plating source and the negative terminal of the voltage source to a conducting layer on the anode body, and then electroplating a layer containing metal over the capacitor. Any metal which can be plated may be used, such metals include electrically conductive metals such as silver, gold, copper, nickel, and mixtures thereof. The electroplated layer over the capacitor provides greater resistance to mechanical shock and allows the welding of a cathode termination means to the electroplated layer of the capacitor.