Techniques described herein address these and other issues by utilizing two or more sensors to take temperature measurements from which a temperature-differential or instantaneous temperature rate-of-change, can be determined. In turn, this can be used to make a highly accurate model of the relationship between the temperature, temperature-differential, and clock circuitry frequency, to accurately estimate the frequency rate-of-change for frequency correction/compensation.

Techniques described herein address these and other issues by utilizing two or more sensors to take temperature measurements from which a temperature-differential or instantaneous temperature rate-of-change, can be determined. In turn, this can be used to make a highly accurate model of the relationship between the temperature, temperature-differential, and clock circuitry frequency, to accurately estimate the frequency rate-of-change for frequency correction/compensation.

A measurement system for determining an energy usage parameter of an electronic device under test is described. The measurement system includes a thermal chamber and an analysis circuit. The thermal chamber includes a housing, a temperature regulator and a thermal control circuit. The housing encloses an interior space of the thermal chamber, wherein the interior space is configured to accommodate the device under test. The thermal control circuit is configured to control the temperature regulator to keep a temperature of the interior space at a predefined reference temperature. The thermal control circuit is configured to determine a power consumption of the temperature regulator, wherein the power consumption is associated with keeping the temperature of the interior space at the predefined reference temperature. The analysis circuit is configured to determine at least one energy usage parameter of the device under test based on the determined power consumption. Further, a method of determining an energy usage parameter of an electronic device under test is described.

A measurement system for determining an energy usage parameter of an electronic device under test is described. The measurement system includes a thermal chamber and an analysis circuit. The thermal chamber includes a housing, a temperature regulator and a thermal control circuit. The housing encloses an interior space of the thermal chamber, wherein the interior space is configured to accommodate the device under test. The thermal control circuit is configured to control the temperature regulator to keep a temperature of the interior space at a predefined reference temperature. The thermal control circuit is configured to determine a power consumption of the temperature regulator, wherein the power consumption is associated with keeping the temperature of the interior space at the predefined reference temperature. The analysis circuit is configured to determine at least one energy usage parameter of the device under test based on the determined power consumption. Further, a method of determining an energy usage parameter of an electronic device under test is described.

A system and method for building energy-related changes evaluation with the aid of a digital computer are provided. Obtained is a total amount of fuel purchased for a building over a set period from which an existing amount of the fuel consumed for space heating is derived. Characteristics including thermal performance and furnace and delivery efficiencies of the building for both existing and proposed equipment are obtained, including remotely controlling a heating source inside the building. The thermal performance and furnace and delivery efficiencies characteristics of the existing and proposed equipment are expressed as interrelated ratios. An amount of fuel to be consumed for space heating is evaluated as a function of the existing amount of the fuel consumed for space heating and the ratios of the existing and proposed equipment.

A system and method for building energy-related changes evaluation with the aid of a digital computer are provided. Obtained is a total amount of fuel purchased for a building over a set period from which an existing amount of the fuel consumed for space heating is derived. Characteristics including thermal performance and furnace and delivery efficiencies of the building for both existing and proposed equipment are obtained, including remotely controlling a heating source inside the building. The thermal performance and furnace and delivery efficiencies characteristics of the existing and proposed equipment are expressed as interrelated ratios. An amount of fuel to be consumed for space heating is evaluated as a function of the existing amount of the fuel consumed for space heating and the ratios of the existing and proposed equipment.

An electrical control system for controlling a variable transmittance window is disclosed. The system comprises a driver circuit in communication with an electro-optic element. A controller is in communication with the driver circuit. The controller is configured to identify a temperature condition of the electro-optic element and adjust an output voltage supplied to the electro-optic element in response to the temperature condition.

The overall thermal performance of a building UA.sup.Total can be empirically estimated through a short-duration controlled test. Preferably, the controlled test is performed at night during the winter. A heating source is turned off after the indoor temperature has stabilized. After an extended period, such as 12 hours, the heating source is briefly turned back on, such as for an hour, then turned off. The indoor temperature is allowed to stabilize. The energy consumed within the building during the test period is assumed to equal internal heat gains. Overall thermal performance is estimated by balancing the heat gained with the heat lost during the test period.

The overall thermal performance of a building UA.sup.Total can be empirically estimated through a short-duration controlled test. Preferably, the controlled test is performed at night during the winter. A heating source is turned off after the indoor temperature has stabilized. After an extended period, such as 12 hours, the heating source is briefly turned back on, such as for an hour, then turned off. The indoor temperature is allowed to stabilize. The energy consumed within the building during the test period is assumed to equal internal heat gains. Overall thermal performance is estimated by balancing the heat gained with the heat lost during the test period.

A heater with reduced electromagnetic wave emissions, which has two heating elements separated by an insulating layer and receiving opposite-phase alternating current in a way that cancels out electromagnetic wave emissions.