Abstract: An electronic measuring device utilizes multiple different transducers for supplying signals exhibiting predetermined and typically nonlinear relationships to the multiple input variables sensed by the transducers. The measuring device includes a microcomputer containing stored linearizing information therein relating to the predetermined nonlinear relationship of the signals supplied by the transducers and the variables sensed by the transducers. The microcomputer linearizes each of the signals supplied by the transducers and thereby obtains highly accurate signals indicative of the variables sensed. Depending upon the ultimate determination to be obtained by the device, the linearized signals representative of the input variables may be employed in a polynomial equation calculation conducted by the computer to obtain the output determination.

Abstract: The temperature within a freezer case or refrigeration compartment is operatively determined and controlled by a control system employing a microcomputer which operatively controls a refrigeration system associated with the freezer case. A sensing element is operatively connected to the microcomputer for supplying a signal representative of the freezer compartment temperature. Temperature selector switches establish upper and lower limits of a desired range of temperatures for the freezer case and another selector switch establishes an alarm condition temperature limit. The microcomputer follows a program of comparing the compartment temperature to the upper limit, the lower limit and the alarm condition limit. During normal operation, the microcomputer also controls a refrigerant valve to regulate the compartment temperature within the desired range. If the compartment temperature elevates to the alarm condition limit, the microcomputer energizes a first alarm.

Abstract: A digital thermometer uses a microprocessor computer containing stored information relating to the response characteristics of a transducer to supply a measurement of temperature. The transducer is preferably a thermistor whose resistance varies in a predetermined and nonlinear relation to its temperature. The microprocessor computer includes a read-only memory which has been preprogrammed with piece-wise linearized information approximating the nonlinear relation of resistance and temperature of the thermistor. A current source develops a voltage across the thermistor which is related to the temperature of the thermistor. The voltage across the thermistor is converted into a digital signal, and the digital signal is related to the piece-wise linearized information stored. The temperature equivalent is calculated from a first order algebraic equation determined by the relationship of the digital signal to the stored information.

Abstract: A display unit having a plurality of light emitting segments is directly attached to a circuit board, thereby avoiding use of a separate encapsulated display device. The circuit board is provided with a plurality of electrical conductors permanently attached to its component mounting surface. Electrically conductive leads extend between the light emitting segments of the display unit and the electrical conductors attached to the circuit board. The display unit includes a base supporting member to which the light emitting segments are attached in a desired configuration. The base member is preferably glued with an electrically conductive glue to an electrical conductor attached to the circuit board, thereby simultaneously physically connecting the base member directly and permanently to the circuit board and electrically connecting a common terminal of the light emitting segments to the electrical conductor on the circuit board.

Abstract: A probe of an electronic thermometer, to which a temperature sensing element is attached, is conditioned with heat energy whereby the temperature of the probe is changed to approximately the temperature of the environment whose temperature is to be measured. A thermistor is thermally attached to the probe and provides a measurable electrical characteristic related in a predetermined manner to the temperature experienced by the thermistor. An auxiliary current source supplies a current to the thermistor of sufficient magnitude so that the thermistor acts as a heating element for raising the temperature of the probe. Heat energy is supplied to the probe for a predetermined time or until the temperature of the probe reaches a predetermined limit. The flow of auxiliary current is terminated and the temperature of the probe and its attached thermistor are allowed to equalize to the temperature of the environment.