Abstract: A digital thermometer, having a sensing tip that is integral with a heater, a display, and a microcontroller which samples for rise time and proportionally operates the heater to increase the temperature of the sensing tip in an alternating control sequence that includes a post-heating delay and, thus, the sensing tip quickly arrives at a stable temperature when no further heating is required.

Abstract: A digital thermometer, having a sensing tip that is integral with a heater, a display, and a microcontroller which samples for rise time and proportionally operates the heater to increase the temperature of the sensing tip in an alternating control sequence that includes a post-heating delay and, thus, the sensing tip quickly arrives at a stable temperature when no further heating is required.

Abstract: A system for detecting the existence of a hazardous condition in an area includes a number of battery-powered detecting units whereby each detecting unit is respectively located within a zone within the area and each detecting unit includes a sensing circuit, a battery level monitoring circuit and a transmitting circuit. The sensing circuit senses the existence of a hazardous condition within that respective zone and generates a hazardous condition alert signal in response thereto. The battery level monitoring circuit monitors the level of the battery powering the detecting unit and generates a battery status signal when the battery is at an acceptable level. The transmitting circuit transmits the hazardous condition alert signal and/or the battery status signal. The system also includes a receiving unit which is responsive to the detecting units and includes a receiving circuit, a battery status indicating circuit and a hazard condition alert circuit.

Abstract: An improved heater wire and electro-thermal controller suitable for use in electric heating appliances such as electric blankets and heating pads. The heater wire is formed with a first conductor for heat generation and a second conductor for sensing. The first conductor and second conductor are wound as coaxial spirals with an insulation material electrically isolating the two conductors. The two spirals are counter-wound with respect to one another to insure that the turns cross, albeit on separate planes, several times per inch. With the conductors thus formed, if the insulation separating the conductors fails, the first and second conductors will come into electrical contact to facilitate detection of this hazardous condition. The controller of the present invention includes an electronic control unit a sensor input circuit, a heater driver circuit and a user interface circuit.

Abstract: A safety-assuring control device for an electric blanket which includes a PTC heater includes an integrated circuit microcontroller unit having first and second safety circuit inputs and an output connected to a control input of an electrically controlled heater switch. A neon tube is connected between the primary safety link return conductor of the heater and the first safety circuit input, to indicate whether there is a first type of fault in the PTC heater. A connection between the second safety circuit input and the secondary safety link return conductor of the PTC heater is provided which indicates whether there is a second type of fault in the heater. The microcontroller unit includes a preliminary fault detection circuit for supplying a limited power test signal in a test mode to the heater for a predetermined period of time prior to a full power operation of the heater.