Abstract: A heating, ventilating, and air conditioning (HVAC) system includes a thermostat, a temperature sensor, a plurality of occupancy sensors in a plurality of zones in a room in a building, a plurality of airflow vents in the plurality of zones in the room, and a motor coupled to each of the plurality of airflow vents. The system receives temperature set point data from the thermostat, receives temperature data from the temperature sensor, receives occupancy data from the occupancy sensors, turns on a heating unit or a cooling unit as a function of the temperature set point data from the thermostat and the temperature data from the temperature sensor, and controls the flow of heated air or cooled air into the zones in the room by transmitting a signal to one or more of the motors so as to adjust the plurality of airflow vents in the room.

Abstract: A data center room is adapted to include electronic equipment supported by a floor. At least one wall of the room is formed as a heat exchanger that conducts heat generated by the electronic equipment outside of the room. An airflow path is formed across the wall to provide outside air to move heat away from the ceiling.

Abstract: A thermal management system includes an airflow sensor that measures airflow in an air path inside an enclosure to be cooled, wherein the air path includes a filter and a fan. A controller is responsive to the airflow sensor for monitoring the rate of airflow inside the enclosure and determining the condition of the filter. In one embodiment, the airflow sensor is an active type sensor, such as a thermistor, disposed on circuit boards. In further embodiments, the airflow sensor is disposed proximate a tube through the filter.

Abstract: A power circuit has an input circuit for coupling to a power supply to receive input current. One or more fans are driven with current pulses from an output circuit. Commutation noise from the current pulses back to the power supply is minimized. The commutation noise may be minimized by providing an isolated current source, by staggering the phase of pulses to multiple motors to increase the frequency and filter out the commutation noise, or by a combination thereof.

Abstract: A fan is controlled to remove or provide air from or to an equipment enclosure as a function of a difference in pressure between a front and back of a rack of equipment.

Abstract: A blower is formed with multiple sets of rotatable rings of blades coupled to each other. Multiple inlet rings are correspondingly coupled to the multiple sets of rotatable rings of blades. In one embodiment, the blades may be forward facing blades and include a volute to accomplish pressure recovery. In further embodiments, the blades are backward facing. Such backward facing blades are designed to provide a static pressure rise. In some embodiment, three or more rings of blades with corresponding inlet rings are utilized.

Abstract: A thermal management system includes an airflow sensor that measures airflow in an air path inside an enclosure to be cooled, wherein the air path includes a filter and a fan. A controller is responsive to the airflow sensor for monitoring the rate of airflow inside the enclosure and determining the condition of the filter. In one embodiment, the airflow sensor is an active type sensor, such as a thermistor, disposed on circuit boards. In further embodiments, the airflow sensor is disposed proximate a tube through the filter.

Abstract: A thermistor is pulsed with energy, and a time constant of decay of temperature is calculated based on measured resistance of the thermistor over a number of known intervals. The time constant is representative of the mass air flow. The ambient air temperature may be found without waiting for the thermistor to reach the ambient air temperature.

Abstract: A technique to provide well-balanced airflow in a computer data center that uses fan assisted tiles coupled to a host computer through a network. In an example embodiment, this is accomplished by disposing the fan tiles, including temperature and airflow sensors and a programmable switch to provide a Network address, in multiple locations in raised floor and ceiling of the computer data center. Further, the example embodiments includes coupling the fan tiles to the host computer through the network to control the fan tiles based on the feedback received from the temperature and airflow sensors to provide adaptive airflow balancing and thermal management in the computer data center.

Abstract: A flow rate measurement and direction system including a number of self calibrating probes each having a sensor with two thermistors for providing signals related to the flow rate; and a connector for interfacing the sensor with a monitor, the connector including a memory for storing calibration data unique to each of the thermistors. The monitor includes a microprocessor for polling the memory and for extracting the calibration data, for converting the signals provided by the thermistors into calibrated signals by applying the extracted calibration data to the signals, and a routine for determining the flow direction.

Abstract: A measurement system including a plurality of self calibrating probes. Each probe has a sensor for providing a signal related to a physical parameter to be measured, and a connector for interfacing the sensor with a monitor. The connector includes a memory device for storing calibration data unique to the sensor. A cable interconnects the sensor with the connector. The monitor of the system includes a microprocessor for polling the storage device on the probe to extract the calibration data, and a software routine which converts the signal provided by the sensor into a calibrated signal and applies the extracted calibration data to the signal provided by the sensor.

Abstract: A digital, back EMF, single coil, sensorless up/down counter frequency adjustment system for a d.c. motor includes means for detecting the occurrence of a null voltage during the back EMF commutation state of a field coil; counter means for counting in one direction during the back EMF commutation state and for counting in the opposite direction when the null voltage is detected; means, responsive to the counter means, for ascertaining the final count of the counter means; and means, responsive to the means for ascertaining, for adjusting the frequency of initiation of the commutation states when a non-zero count is ascertained for synchronizing the field coil and the rotor.

Abstract: Early detection and warning of wetness in a diaper leads to an early change of diapers, keeping the infant dry and healthy. This invention monitors the diaper for dryness by sensing the conductance between two terminals in contact with the diaper. The device aids in toilet training the infant by learning wetting patterns and providing early warning. The device promotes the efficient use of diapers and reduces the cost of using diapers.

Abstract: A gas flow temperature probe includes a sensor device for sensing the ambient gas cooling rate and temperature; a prenormalizer circuit responsive to and remote from the sensor device for detecting gas cooling rate and temperature signals from the sensor device and for providing calibration data unique to the probe for normalizing the detected gas cooling rate and temperature to generate a normalized gas flow and temperature sensed by the probe; and an elongated flexible cable interconnecting the sensor device and the prenormalizer circuit for transmitting the ambient gas cooling rate and temperature signals from the sensor device to the prenormalizer circuit; a gas flow temperature monitor circuit includes a multiplexer circuit for real time sampling of a number of probes; a scheduler circuit for defining the sampling rate; and a normalizer circuit for combining the gas cooling rate and temperature signals and the calibration data from the prenormalizer circuit for each probe and generating normalized gas fl