Abstract: A temperature sensor device has a digital interface with a first memory storing a current temperature value which can be read through the digital interface and a second memory storing a rate of temperature change value which can be read through the digital interface. Such a temperature sensor can be preferably used in a system with a cooling fan and a processor coupled with the digital interface of the temperature sensor. The processor is operable to control the cooling fan based on temperature measurement values and the rate of change in temperature retrieved from the temperature sensor through the digital interface.

Abstract: System and method for initiating rotation of a rotor in a motor. The motor may include the rotor and a plurality of pairs of electromagnets. A rotation period may be determined. One or more pairs of electromagnets of the plurality of pairs of electromagnets may be excited at a first excitation level. The excited one or more pairs of electromagnets may be determined based on the rotation period. The excitation level may be decreased, over a first period of time, to a second excitation level. The second excitation level may be a lower excitation level than the first excitation level. The excitation level may be increased, over a second period of time, to a third excitation level. The third excitation level may be a higher excitation level than the second excitation level. The rotation period may be decreased over the first and second periods of time.

Abstract: A control circuit for controlling the rotational speed of a fan may include a memory element to store operating data corresponding to an operational profile of the fan defined by RPM (revolutions per minute) versus temperature, with the operating data comprising a respective temperature value and a respective RPM value for each respective operating point representing a change in slope of a function that corresponds to the operational profile of the fan. A processing unit may receive a present temperature value, retrieve the operating data from the storage unit, and identify a pair of consecutive operating points corresponding to the present temperature. The processing unit may calculate a desired RPM value corresponding to the present temperature value by performing linear interpolation between the pair of consecutive operating points, and provide the desired RPM value to a closed-loop fan controller to control the fan according to the desired RPM value.

Abstract: A temperature sensor device has a digital interface with a first memory storing a current temperature value which can be read through the digital interface and a second memory storing a rate of temperature change value which can be read through the digital interface. Such a temperature sensor can be preferably used in a system with a cooling fan and a processor coupled with the digital interface of the temperature sensor. The processor is operable to control the cooling fan based on temperature measurement values and the rate of change in temperature retrieved from the temperature sensor through the digital interface.

Abstract: An improved hydroponic nutrient delivery gardening system apparatus is described. This improved hydroponic delivery gardening system apparatus improves upon existing systems by minimizing the effects of sunlight and heat on the nutrient solution system without the use of an external nutrient cooling system, improve nutrient availability to roots, improve oxygen availability to roots, and improve the consistency of, and the ability to accurately measure, the pH of the media and nutrient mix.

Abstract: A motor includes a rotor and a plurality of pairs of electromagnets. The energy needed for alignment of the rotor is used to generate the first movement in forced commutation and may be combined with the initial energy to start the motor. The logic is configured to align the rotor by energizing the three coils of the motor. PWM is applied to the first coil to control current on the coils; when a maximum PWM duty cycle is reached, the coil not required to rotate the correct direction are released, thereby initiating motion in a rotor. A rotation period is determined. One or more pairs of electromagnets are excited at a first excitation level which may be increased, over a second period, to a second level. The second level may be a higher level than the first level. The rotation period may be decreased over the first and second periods.

Abstract: A resistive sensing touch panel may include row receiver tracks and column drive tracks. A controller may send and receive control signals and sense signals, respectively, to and from the resistive touch panel. The resistive touch panel may provide sense signals when a touch of the panel is detected. The sense signals may be sampled on a number of rows. When sampling a given row, the controller may change the termination of that row by coupling the end of the sampled row to a resistor having a higher value then terminating resistors coupled to the end of non-sampled rows that are adjacent to the sampled row. The controller may further pull the terminating resistors coupled to the end of the non-sampled adjacent rows to a supply rail voltage while the sampled row is being sampled.

Abstract: A control method for a sensor-less, brushless, three-phase DC motor. The stator coil in the electromagnets inside the motor may be used as the inductive element through which a voltage regulator can regulate the current as a means of regulating the output voltage. The value of the control signal provided to the drivers controlling power to the coils may be calculated based on at least the rail voltage, as measured in real time. This allows for a wide variation of input voltages, while maintaining a relatively constant output power to the motor. In general, by taking into account the value of the rail voltage when determining the final value of the control signal that is applied to the stator coils, the maximum current through the stator coils may be scaled to the same magnitude current that would be expected to flow through the coils if the rail voltage were the rated (nominal) fan/motor voltage, even when the actual rail voltage is different, e.g. higher than the rated fan/motor voltage.

Abstract: A control method for a sensor-less, brushless, three-phase DC motor. The effects of commutation on the motor may be minimized using a sinusoidal current drive on each electromagnet. The “off” times and/or the “on” times of the drive transistors controlling the electromagnets in a full “H-bridge” configuration drive scheme may be delayed. By overlapping the drive signals to the electromagnets with respect to a commutation command, the effects of switching between electromagnets may be minimized. In addition, the “on” and “off” times may also be adjusted during the overlapping to further ensure that the coils continuously conduct current, and that the current does not change direction during the switching. The delays, and hence the overlap times of the coil drive signals may be dynamically controlled, for example by using digital timers, making the response predictable and easily controlled.

Abstract: A system and method are presented for aligning a rotor in a motor. The motor may include the rotor and a plurality of pairs of electromagnets. One or more pairs of electromagnets may be excited at a first excitation level. The one or more pairs of electromagnets may be less than all of the plurality of pairs of electromagnets. The excitation of the one or more pairs of electromagnets may be increased to a second excitation level over a first period of time. The excitation of the one or more pairs of electromagnets may be decreased to a third excitation level over a second period of time. Exciting the one or more pairs of electromagnets, increasing the excitation, and decreasing the excitation may cause the rotor to stop in a known position.

Abstract: The present disclosure provides a selective data acquisition system of a matrix resistive touch panel and a method of using the data acquisition system to selectively acquire data on a touch panel. Each analog signal from the sensing track is tested with its own threshold value to determine whether the characteristics of the analyzed signal are sufficient to constitute a user's actuation on the touchscreen. If the analyzed analog signal exceeds or otherwise clears the threshold, the selective data acquisition system converts the signal into a digital word. Conversely, if the analyzed analog signal falls below or otherwise fails the threshold, the selective data acquisition system does not convert the signal. This process continues for all analog signals from the sensing tracks.

Abstract: A control method for a brushless, three-phase DC motor. The motor may include a plurality of electromagnets and a rotor. A voltage induced by rotation of a rotor may be sampled at an expected zero crossing value to produce a first sampled voltage value. An average of a plurality of sampled voltage values, including voltage values sampled at a plurality of prior expected zero crossing values, may be calculated. A delta zero crossing error may be calculated. The delta zero crossing error may be calculated based on a difference between the first sampled voltage value and the calculated average. The plurality of electromagnets may be commutated. Commutation timing for the plurality of electromagnets may be determined based at least in part on the delta zero crossing error.

Abstract: A system and method are presented for aligning a rotor in a motor. The motor may include the rotor and a plurality of pairs of electromagnets. One or more pairs of electromagnets may be excited at a first excitation level. The one or more pairs of electromagnets may be less than all of the plurality of pairs of electromagnets. The excitation of the one or more pairs of electromagnets may be increased to a second excitation level over a first period of time. The excitation of the one or more pairs of electromagnets may be decreased to a third excitation level over a second period of time. Exciting the one or more pairs of electromagnets, increasing the excitation, and decreasing the excitation may cause the rotor to stop in a known position.

Abstract: A control method for a sensor-less, brushless, three-phase DC motor. A pulse-width modulation (PWM) duty cycle may be calculated. A voltage induced by rotation of a rotor may be sampled at a first expected zero crossing value to produce a first sampled voltage value. An average of a plurality of sampled voltage values, including voltage values sampled at a plurality of prior expected zero crossing values and the first sampled voltage value, may be calculated. The first sampled voltage value may be subtracted from the calculated average to produce a delta zero crossing error (ZCE). The current value of an integral term corresponding to a rotational period may be updated according to the sign of the ZCE. The integral term may be updated periodically and multiple times during each rotational period. The ZCE may be subtracted from the integral term, and the resulting value may be used to generate one or more time values.

Abstract: A resistive sensing touch panel may include row receiver tracks and column drive tracks. A controller may send and receive control signals and sense signals, respectively, to and from the resistive touch panel. The resistive touch panel may provide sense signals when a touch of the panel is detected. The sense signals may be sampled on a number of rows. When sampling a given row, the controller may change the termination of that row by coupling the end of the sampled row to a resistor having a higher value then terminating resistors coupled to the end of non-sampled rows that are adjacent to the sampled row. The controller may further pull the terminating resistors coupled to the end of the non-sampled adjacent rows to a supply rail voltage while the sampled row is being sampled.

Abstract: A system and method are presented for aligning a rotor in a motor. The motor may include the rotor and a plurality of pairs of electromagnets. One or more pairs of electromagnets may be excited at a first excitation level. The one or more pairs of electromagnets may be less than all of the plurality of pairs of electromagnets. The excitation of the one or more pairs of electromagnets may be increased to a second excitation level over a first period of time. The excitation of the one or more pairs of electromagnets may be decreased to a third excitation level over a second period of time. Exciting the one or more pairs of electromagnets, increasing the excitation, and decreasing the excitation may cause the rotor to stop in a known position.

Abstract: A control method for a brushless, three-phase DC motor. A voltage induced by rotation of a rotor may be sampled at a first expected zero crossing value to produce a first sampled voltage value. An average of a plurality of sampled voltage values, including voltage values sampled at a plurality of prior expected zero crossing values and the first sampled voltage value, may be calculated. The first sampled voltage value may be subtracted from the calculated average to produce a delta zero crossing error. A pulse-width modulation duty cycle may be adjusted based on the delta zero crossing error. The pulse-width modulation duty cycle may be used to control a rotational velocity of the rotor.

Abstract: A control circuit for controlling the rotational speed of a fan may include a memory element to store operating data corresponding to an operational profile of the fan defined by RPM (revolutions per minute) versus temperature, with the operating data comprising a respective temperature value and a respective RPM value for each respective operating point representing a change in slope of a function that corresponds to the operational profile of the fan. A processing unit may receive a present temperature value, retrieve the operating data from the storage unit, and identify a pair of consecutive operating points corresponding to the present temperature. The processing unit may calculate a desired RPM value corresponding to the present temperature value by performing linear interpolation between the pair of consecutive operating points, and provide the desired RPM value to a closed-loop fan controller to control the fan according to the desired RPM value.

Abstract: A control circuit for controlling the rotational speed of a fan may include a memory element to store operating data corresponding to an operational profile of the fan defined by RPM (revolutions per minute) versus temperature, with the operating data comprising a respective temperature value and a respective RPM value for each respective operating point representing a change in slope of a function that corresponds to the operational profile of the fan. A processing unit may operate to receive a present temperature value, retrieve the operating data from the storage unit, and identify a pair of consecutive operating points such that the present temperature value is greater than a lower respective temperature value of the pair of consecutive operating points, and lower than a higher respective temperature value of the pair of consecutive operating points.

Abstract: System and method for digitizing analog voltage signals. A first voltage signal may be received at a comparator. A ramp signal may be received at the comparator. The ramp signal may be generated by a ramp generator. An output signal may be generated by the comparator. The output signal may indicate whether the analog voltage signal or the ramp signal is greater. The output signal may be conveyed to logic circuitry by the comparator. Control information may be conveyed by the logic circuitry to the ramp generator. The ramp generator may generate the ramp signal based on the control information. The logic circuitry may determine a digital representation of the first voltage signal based on the output signal from the comparator and the control information.