Abstract: A peak power measurement as a function of various system parameters is made to determine completion of a proper heating operation; in one embodiment by measuring peak power delivered to a level as a function of temperature within a specified time period for a specific load; and in another embodiment by the plot of peak power and ramp-up and ramp-down levels as a function of time.

Abstract: This invention relates to heat-recoverable devices that are self-heating and auto-regulating. The heat-recoverable articles of this invention comprise the combination of a heat-recoverable material and lossy heating particles, such as ferromanetic or ferrimagnetic particles, which produce heat when subjected to an alternating magnetic field and have a Curie temperature at or above the recovery temperature of the material and preferably below the decomposition temperature of the material. The particles can be in an electrically non-conductive layer, on or in thermal contact with the heat-recoverable material or can be dispersed in the heat-recoverable material. The system of this invention includes the heat-recoverable device or article, an induction coil for producing the magnetic field and an alternating current power supply for the induction coil. Preferably the power supply is high frequency and constant current, which produces efficient heating and preferred auto-regulating properties.

Abstract: A temperature self-regulating heater has a thin first layer of high magnetic permeability, a second layer of electrially conductive non-magnetic material forming a substrate and a heat conductive dielectric disposed between the layers. A varying (preferably r.f.) magnetic field is imposed upon the exposed surface of the first layer and the material to be heated may be placed in contact with an exposed surface of the second layer or may be the dielectric. The heater may be employed with an induction stove wherein the first layer is disposed above the stove's induction coil and the second layer can be the bottom of a cooking utensil.

Abstract: A heat shrinkable sleeve or the like is heated by a ferromagnetic member which in turn is heated by a varying magnetic field, the ferromagnetic having a Curie temperature above the shrink temperature of the sleeve whereby when the sleeve is heated to its shrink temperature it tightly groups the members to be joined. Preferably a constant temperature is employed so that the ferromagnetic material will not rise above its Curie temperature.

Abstract: A self-regulating heater is provided by placing ferrite-type body member, which is highly lossy when exposed to a high frequency magnetic field and has a predetermined Curie temperature, on or around a central conductor which is connected or is adapted to be connected to a power source which provides high frequency alternating current to the conductor. The current passing through the central conductor produces a magnetic field around the conductor, which causes the ferrite-type body to be heated by internal losses to its Curie temperature. The heater self-regulates at the Curie temperature of the ferrite-type body. The power source is preferably a constant current, impedance matched power source. The ferrite-type body member can be ferromagnetic or ferrimagnetic. The ferrite-type body is preferably ferrimagnetic, such as ferrite beads, rings, and the like, which heat by hysteresis losses.

Abstract: A flexible circuit which may be a strap or a board or the like has a plurality of conductors exposed on one surface in a predetermined array and a heater disposed on the opposed surface so as to heat the exposed conductors. The exposed conductors may have solder or the heat activated conductive bonding material applied thereto so that the flexible circuit may be directly connected to a component, a printed circuit board, a connector or the like. If a reusable bonding material, such as solder, is employed the heater may be utilized to both connect and disconnect the flexible circuit.

Abstract: An electrical connector including a member, a heater element comprising a coating of ferromagnetic material on the member and a fusible material. The fusible material is melted when the ferromagnetic material is heated inductively by an alternating magnetic field. The connector can be attached to an end of a coaxial cable. The member can comprise a metal ferrule soldered around a tubular conductor of the coaxial cable and/or a central contact having a bore in one axial end thereof in which a central conductor of the coaxial cable is soldered. A dielectric coating can be provided over the coating of ferromagnetic material on the ferrule and/or central contact. The fusible material can be held in the bore in the central contact or between the dielectric coating and an electrically insulating heat-shrinkable sleeve around the ferrule. The ferrule can include one or more ports therethrough for passage of the fusible material into contact with the tubular conductor.

Abstract: A relatively flat, rectangular multipin connector has a terminal end to each pin adapted to receive the stripped end of a wire to be soldered thereto. Both surfaces of the pin may be arcuate in cross-section, one surface being concave and adapted to receive a wire to be soldered thereto. The convex surface has a covering of a thin layer of ferromagnetic material having an effective Curie temperature above the fusion temperature of the solder to be employed. A sleeve of heat shrinkable material has an interior ring of solder and is positioned over the region of contact between the wire and terminal end of the pin and has fusible plastic at each end. Each wire is placed on an individual pin and successively clamped in place, each between a different pair of jaws.

Abstract: A desoldering tool has a removable heater cartridge and a base unit having an assembly interior including a solder collection chamber and a removable vacuum source for developing a vacuum in and above the chamber and a removable porous solder retention pad located between the vacuum source and the solder collection chamber, the cartridge having a temperature self-regulating heater therein, a tail pipe extending from a hollow tip of the cartridge to a position above the solder collection chamber, and a vacuum seal between the cartridge and the base unit to maintain the vacuum and reduce transfer of heat from the tip. The tool is readily converted to a soldering iron or a hot air gun.

Abstract: A basically commercially fast heat highly efficient griddle has interchangeable griddle plates including magnetically permeable materials having Curie temperatures which may be the same or different to provide different cooking temperatures, the plates being heated by induction coils providing sufficient energy to heat the plates to their effective Curie temperatures in the presence of loads and of a design to maintain a uniform cooking temperature across the griddle plate to within less than an inch of the edges of the plates. The plates may be placed in an enhanced idle condition at cooking temperature by placing a cover over the plates or region of a plate not in use. Increased efficiency is further due to an insulator blanket placed between the griddle plates and coils.

Abstract: A heater (seed) and system for subjecting body tissue to closely controlled hyperthermia or higher temperatures includes a core of ferromagnetic material having a high resistivity or resistivity of a non-conductor enclosed with a bio-compatible non-magnetic conductive sheath and excited by a coil positioned to establish a magnetic field coupled to the seed. The core is dimensioned so as to reduce demagnetizing effects to acceptable levels. The thickness of the conductive sheath is optimized to maximize heat generation to achieve a heat generating capacity which is considerably greater than that of the bare ferromagnetic material.

Abstract: This invention provides a system for providing heat to a substrate in an alternating magnetic field using lossy heating particles. This invention in particular discloses an article which is a combination of a base material and lossy heating particles capable of producing the desired heat and capable of being self-regulating at a preselected Curie temperature when subjected to an alternating magnetic field. The article of this invention is adapted to be placed on a substrate in order to heat the substrate in an alternating magnetic field and is adapted to provide the removal of the particles from the substrate after the heating is completed. Preferred materials for the article of this invention are gel materials having a cone penetration of at least about 50(10.sup.-1 mm) and at least about 100% elongation.

Abstract: A single constant voltage power supply concurrently supplies a plurality of independent loads each with an independently selectable constant current load without interaction between the loads (currents) by employing a plurality of parallel connected circuits of electrical lengths equal to (2n-1)90.degree. each connected between the constant voltage source and a different one of said loads.

Abstract: This invention provides a system for providing heating in an alternating magnetic field using lossy heat producing magnetic particles. This invention disclosed a system comprising a combination of particles wherein the first particles are lossy heat producing particles, which have a preselected Curie temperature to provide self-regulating heating in the alternating magnetic field, and the second particles are nonlossy particles which have high permeability which are not heat producing particles but which maintain the coupling of the magnetic circuit and maintain the desired magnetic field focus and intensity through the area in which the first lossy heat producing particles are positioned.

Abstract: In a plastic pipe joining system a plastic sleeve is provided to extend on both sides beyond the region of contact or closest approach to one another of pipes to be joined with the sleeve being fused to both pipes, the sleeve heated to Curie temperature of high mu material excited by an externally generated high frequency magnetic field. The heater may be embedded in the sleeve and the sleeve may also be employed with end caps that extended over the sleeve, the end caps and sleeve being fused to one another and the pipes by heaters carried by the end caps or the sleeve. An external heater may also be employed which in conjuction with shaped end members provides the sleeve with beveled or tapered edges to enhance the ability of the sleeve to withstand cracking.

Abstract: A connector which acts upon itself contains a fusible bonding material the connector forming a part of a temperature autoregulating electrical heater whereby upon application of a generally constant a.c. current to the heater, the temperature of the heater rises to and is maintained at slightly above the melting temperature of the fusible material.

Abstract: A relatively flat, rectangular multipin connector has a terminal end to each pin adapted to receive the stripped end of a wire to be soldered thereto. Both surfaces of the pin may be arcuate in cross-section, one surface being concave and adapted to receive a wire to be soldered thereto. The convex surface has a covering of a thin layer of ferromagnetic material having an effective Curie temperature above the fusion temperature of the solder to be employed. A sleeve of heat shrinkable material has an interior ring of solder and is positioned over the region of contact between the wire and terminal end of the pin and has fusible plastic at each end. Each wire is placed on an individual pin and successively clamped in place, each between a different pair of jaws.

Abstract: This invention provides a method for soldering using induction heating, which is accomplished by the use of lossy heating particles in or on the solder. The method of this invention provides direct heating of the solder itself through induction heating of the magnetic particles in an alternating magnetic field. The magnetic particles useful in this invention can be ferromagnetic particles or ferrimagnetic particles, preferably ferrites, which have a Curie temperature at least equal to the flow temperature of the solder. Selection of the magnetic lossy heating particles with the appropriate Curie temperature for the system in which the particles are being used provides a system in which the temperature is self-regulating when the alternating magnetic field is applied. This self-regulation feature prevents overheating of the solder in the articles being soldered.

Abstract: A self-regulating heater including a body of electrically non-conductive material, an induction coil embedded within the body, lossy heating particles dispersed within the body and connection terminals for supplying power to the induction coil. The lossy heating particles produce heat when subjected to an alternating magnetic field produced by the induction coil. The lossy heating particles have a Curie temperature approximately equal to a substantially constant auto-regulation temperature at which the body is heated. The connection terminals supply power to the induction coil so that the induction coil can produce an alternating magnetic field of sufficient intensity to cause the lossy heating particles to heat the body to the auto-regulation temperature.

Abstract: A thermal atherectomy catheter has a tip of high magnetic permeability cylindrical stem with an enlarged head at one end and an enlarged collar at the other end, a coil of wire wrapped about the stem adjacent the head and removed from said collar, a sleeve of ferromagnetic material disposed about the coil and a second sleeve of non-magnetic outer sleeve extending between and of the diameter of the head and collar to define a space between the sleeves whereby the outer sleeve to collar are maintained at a lower temperature than the head.