Abstract: An apparatus and process are provided for regulating the voltage across a resistive or inductive load by phase angle control of the applied load voltage. Instantaneous load voltage is compared with a preset reference value to control the phase angle of the applied load voltage by means of rms voltage approximation feedback control. A visual display can be provided to assist the user in establishing the preset reference value.

Abstract: An oven temperature control circuit utilizes one or more light emitting diodes to establish a clamping voltage that limits the voltage at the input of a circuit component, such as an analog-to-digital converter, when a sensor, such as a thermistor, is connected to the input of the circuit component and the sensor is subjected to an EMI pulse. A method is provided for continued execution of a heating process after an unavoidable and unintentional interruption.

Abstract: The present invention is used to heat seal seams, and the like, of item holding means such as plastic bags holding loose fill product like beans, hard candy, pretzels, potato chips, etc. The heating station of the present invention has at least two independently controlled heating positions in each half of a pair of jaws and each heating position is heat insulated from the other and each respectively can provide different amounts of heat to material coming in contact therewith. Accordingly, the bonded areas of item holding means can be manipulated to control local package characteristics, i.e., sealed to have a stronger bond strength at one location that at another location, adjust tear properties to suit marketing methods (such as hole punched top seals) and to control seal integrity.

Abstract: The present invention includes at least one low mass flexible heat transfer member to which there is secured a plurality of electrical resistance paths, for each area of the material to be sealed during an excursion through the heat station. The electrical resistance paths are respectively connected to a power source, or power sources, to generate different quantities of heat respectively at different positions along the heat transfer member. The heat transfer member is flexible and is formed and disposed to push against sealable material to transfer heat thereto and cause said sealable material to be sealed.

Abstract: A cascaded fluid heating for electrically heating to fluid, such as a gaseous fluid in a flameless torch, to a high temperature includes a pump to pump a relative constant stream of fluid through a pair of heating chambers arranged in series. A first electric heating element formed of a nickel-iron alloy having a substantially linear positive temperature coefficient of resistance up to 1100.degree. F. is disposed in the first chamber and heats the fluid stream to a first temperature. A second heating chamber receives the heated fluid from the first chamber and contains a second electric heating element of a material, such as Kanthal A, which does not oxide at temperature up to 2000.degree. F. for heating the fluid to a higher temperature. The first electric heating element acts as a sensor for a temperature controller for the first heating element whereby the current supplied by the controller to the first heating element responsive to the changes in resistance of thereof.

Abstract: The present invention provides a low mass, flexible heat transfer member which is made of a suitable material to transfer heat, as well as a plurality of independent heat generating members to provide zoned heat along a portion of the length of said heat transfer member. The heat generating members are encased in an electrical insulation material which is secured to the heat transfer member. The consolidated structure, i.e. the heat transfer member and heat generating members constitute a flexible strip. The ends of said flexible strip are actually sections of the heat transfer member and these ends are respectively looped around two pins, or studs, and over the respective loops there is positioned an associated slotted hollow tube. The slotted hollow tube is formed to be located in a base of a machine with which the flexible heating means is used.

Abstract: The present invention includes a heating element which is secured to a rigid member and which is located so that when a plastic like material is being formed into a package or bag, by effecting a seam along the side of the package, the inside of said side seam will be heated, in addition to said outside of said side seam to help provide a better sealed seam.

Abstract: The present device incrementally adds or subtracts power units to and from a heating or cooling system and employs a major control board into which are plug-connected a plurality of minor control boards. The minor control boards have varying designs. Some are designed to accept different signals from different types of temperature monitoring means and are designed to convert those different signals into common command signals, while other minor control boards are designed to accept those command signals in order to communicate with and control yet others of said minor control boards to effect a turning on and/or turning off of said heating or cooling power units according to at least two different modes of operation. The major control board provides a power source for the minor control boards and provides the circuit paths to enable the minor control boards to transmit signals among any set of such mounted boards.