Patents Assigned to Weiss Controls, Inc.
  • Publication number: 20180279413
    Abstract: A safety circuit to disrupt power to a heating element of an appliance to be powered through a solid state switch (Tri-ac, Q1), typically a triac, from an AC power source (V1) having a positive half cycle and a negative half cycle delivering power. A low resistance condition is sensed by detecting either the current through or voltage across the solid state switch during the positive half cycle and the negative half cycle of the AC power line, when the solid state AC switch is not actuated. A fault signal is generated to interrupt power to the heating element, preferably by a crowbar circuit opening a fuse, whenever the low resistance condition is detected.
    Type: Application
    Filed: December 15, 2017
    Publication date: September 27, 2018
    Applicant: Weiss Controls Inc.
    Inventors: Lenny Novikov, John William Weiss
  • Patent number: 9320084
    Abstract: A dual heater wire circuit for use with a heating pad or electric blanket includes two independent heater wire circuits. Each heater wire circuit includes a heater wire and a temperature sensor conductor. The temperature sensor conductor of each heater wire circuit is connected to a capacitor, or to a resistor, to define with the capacitor or resistor a voltage divider circuit. The juncture between the sensor conductors and either the capacitor or the resistor is provided to the input of a microprocessor. The electrical resistance of the temperature sensor conductors varies with temperature. The signal provided to the microprocessor from the voltage dividers formed between the sensor conductors of the heater wires and either the capacitor or resistor will vary in phase or voltage relative to the temperature of the heater wires. The microprocessor controls the duty cycle of the power signal provided to the heater wires.
    Type: Grant
    Filed: November 20, 2012
    Date of Patent: April 19, 2016
    Assignee: Weiss Controls, Inc.
    Inventors: John W. Weiss, Kuang-Pu Liao
  • Publication number: 20160037582
    Abstract: A safety circuit to disrupt power to a heating element of an appliance to be powered through a solid state switch (Tri-ac Q1), typically a triac, from an AC power source (V1) having a positive half cycle and a negative half cycle delivering power. A low resistance condition is sensed by detecting either the current through or voltage across the solid state switch during the positive half cycle and the negative half cycle of the AC power line, when the solid state AC switch is not actuated. A fault signal is generated to interrupt power to the heating element, preferably by a crowbar circuit opening a fuse, whenever the low resistance condition is detected.
    Type: Application
    Filed: March 14, 2014
    Publication date: February 4, 2016
    Applicant: Weiss Controls Inc.
    Inventors: Lenny NOVIKOV, William John WEISS
  • Patent number: 9089010
    Abstract: A safety overheat protection circuit for flexible heater wire used in heating pads and electric blankets. The heater wire includes a low melt temperature fuse-able layer and a conductive core. A polymetric positive temperature coefficient (PPTC) device is used in series with the heater wire in a configuration so that a hot spot anywhere along the length of the wire will cause the fuse-able layer to melt and the heater wire to short to the conductive core, increasing the current and causing the PPTC device to change to a high impedance state significantly removing power to the heater wire. In addition, dual circuits having the same operating target temperature are presented as a safe method of temperature control.
    Type: Grant
    Filed: November 29, 2011
    Date of Patent: July 21, 2015
    Assignee: Weiss Controls, Inc.
    Inventors: John W. Weiss, Kuang-Pu Liao
  • Patent number: 8772679
    Abstract: Methods and system for controlling a heater conductor in a heating element including a sensor conductor separated from the heater conductor by an NTC layer. The heating element is coupled to a control circuit and the flow of electricity from a direct current source through the circuit is controlled such that a change of the resistance of the NTC layer is indicative of the temperature of the heater conductor. This resistance is detected based on a time or amplitude analysis and based thereon, a heating mode of the heater conductor is controlled. In a variation, the circuit is operated in a two-period measurement mode wherein the energy transferred through the NTC layer in one period is equal and opposite to the energy transferred through the NTC layer in the other period.
    Type: Grant
    Filed: March 19, 2010
    Date of Patent: July 8, 2014
    Assignee: Weiss Controls, Inc.
    Inventor: Lenny Novikov
  • Publication number: 20130134149
    Abstract: A dual heater wire circuit for use with a heating pad or electric blanket includes two independent heater wire circuits. Each heater wire circuit includes a heater wire and a temperature sensor conductor. The temperature sensor conductor of each heater wire circuit is connected to a capacitor, or to a resistor, to define with the capacitor or resistor a voltage divider circuit. The juncture between the sensor conductors and either the capacitor or the resistor is provided to the input of a microprocessor. The electrical resistance of the temperature sensor conductors varies with temperature. The signal provided to the microprocessor from the voltage dividers formed between the sensor conductors of the heater wires and either the capacitor or resistor will vary in phase or voltage relative to the temperature of the heater wires. The microprocessor controls the duty cycle of the power signal provided to the heater wires.
    Type: Application
    Filed: November 20, 2012
    Publication date: May 30, 2013
    Applicant: WEISS CONTROLS, INC.
    Inventor: Weiss Controls, Inc.
  • Publication number: 20100237060
    Abstract: Methods and system for controlling a heater conductor in a heating element including a sensor conductor separated from the heater conductor by an NTC layer. The heating element is coupled to a control circuit and the flow of electricity from a direct current source through the circuit is controlled such that a change of the resistance of the NTC layer is indicative of the temperature of the heater conductor. This resistance is detected based on a time or amplitude analysis and based thereon, a heating mode of the heater conductor is controlled. In a variation, the circuit is operated in a two-period measurement mode wherein the energy transferred through the NTC layer in one period is equal and opposite to the energy transferred through the NTC layer in the other period.
    Type: Application
    Filed: March 19, 2010
    Publication date: September 23, 2010
    Applicant: Weiss Controls, Inc.
    Inventor: Lenny Novikov
  • Patent number: 7180037
    Abstract: An improved control device and method is usable with flexible heating wire having a conductive core with a Negative Temperature Coefficient (NTC) layer and a helically wound heater conductor within an insulative outer sheath. The conductive core is coupled to a control circuit, a phase shift relative to the AC power supply being indicative of the temperature of the wire. The nonlinear nature of the NTC layer enhances the detection of local hot spots anywhere along the length of the wire. Precise temperature measurement is achieved by measuring the time differences between two zero crossings and the power to the heater compensates for abnormal use such as bunching of the heater wire. The control of the heater wire is particularly suitable for use with appliances such as heating pads and electric blankets.
    Type: Grant
    Filed: May 23, 2005
    Date of Patent: February 20, 2007
    Assignee: Weiss Controls, Inc.
    Inventor: John W. Weiss