Abstract: A temperature calibration device uses Peltier cells for heating and cooling. The Peltier cells are connected to a relay that connects the cells to each other in one configuration for heating and a different configuration for cooling. The Peltier cells also receive supply voltages having different magnitudes and polarities for heating and cooling. By changing the manner in which the Peltier cells are connected to each other and using different supply voltages for heating and cooling, the cells are able to operate closer to their specified maximum temperature differential without sacrificing the useful life of the cells.

Abstract: A temperature calibration device uses Peltier cells for heating and cooling. The Peltier cells are connected to a relay that connects the cells to each other in one configuration for heating and a different configuration for cooling. The Peltier cells also receive supply voltages having different magnitudes and polarities for heating and cooling. By changing the manner in which the Peltier cells are connected to each other and using different supply voltages for heating and cooling, the cells are able to operate closer to their specified maximum temperature differential without sacrificing the useful life of the cells.

Abstract: A temperature calibration device uses Peltier cells for heating and cooling. The Peltier cells are connected to a relay that connects the cells to each other in one configuration for heating and a different configuration for cooling. The Peltier cells also receive supply voltages having different magnitudes and polarities for heating and cooling. By changing the manner in which the Peltier cells are connected to each other and using different supply voltages for heating and cooling, the cells are able to operate closer to their specified maximum temperature differential without sacrificing the useful life of the cells.

Abstract: An externally powered temperature calibration device includes a system that provides a warning of high temperatures within the device after the device has been disconnected from the external power. The warning system includes a capacitor that provides power to a light-emitting diode (“LED”) after the calibration device has been disconnected from the external power. A temperature sensor monitors the temperature of an internal component. An output signal from the sensor is used to control a switch that connects the capacitor to one of several resistors having different resistances. The switch therefore controls the discharge rate of the capacitor based on the sensed temperature at the time the calibration device was disconnected from the external power. As a result, the period during which the capacitor powers the LED can be commensurate with the time required for the internal component to cool from its initial temperature.

Abstract: A temperature calibration device uses Peltier cells for heating and cooling. The Peltier cells are connected to a relay that connects the cells to each other in one configuration for heating and a different configuration for cooling. The Peltier cells also receive supply voltages having different magnitudes and polarities for heating and cooling. By changing the manner in which the Peltier cells are connected to each other and using different supply voltages for heating and cooling, the cells are able to operate closer to their specified maximum temperature differential without sacrificing the useful life of the cells.

Abstract: An externally powered temperature calibration device includes a system that provides a warning of high temperatures within the device after the device has been disconnected from the external power. The warning system includes a capacitor that provides power to a light-emitting diode (“LED”) after the calibration device has been disconnected from the external power. A temperature sensor monitors the temperature of an internal component. An output signal from the sensor is used to control a switch that connects the capacitor to one of several resistors having different resistances. The switch therefore controls the discharge rate of the capacitor based on the sensed temperature at the time the calibration device was disconnected from the external power. As a result, the period during which the capacitor powers the LED can be commensurate with the time required for the internal component to cool from its initial temperature.