An aerosol delivery device is provided that includes a power source, a heating element, a switch coupled to and between the power source and the heating element, and processing circuitry coupled to the switch. The processing circuitry outputs a PWM signal during a heating time period to cause the switch to switchably connect and disconnect the output voltage to the heating element to power the heating element. The processing circuitry outputs a pulse of known current to the heating element, and measure voltage across the heating element, between adjacent pulses of the PWM signal. And the processing circuitry calculates the resistance of the heating element based on the known current and the voltage, calculates the temperature of the heating element based on the resistance, and adjusts a duty cycle of the PWM signal when the temperature deviates from a predetermined target.

An aerosol delivery device is provided that includes a power source, a heating element, a switch coupled to and between the power source and the heating element, and processing circuitry coupled to the switch. The processing circuitry outputs a PWM signal during a heating time period to cause the switch to switchably connect and disconnect the output voltage to the heating element to power the heating element. The processing circuitry outputs a pulse of known current to the heating element, and measure voltage across the heating element, between adjacent pulses of the PWM signal. And the processing circuitry calculates the resistance of the heating element based on the known current and the voltage, calculates the temperature of the heating element based on the resistance, and adjusts a duty cycle of the PWM signal when the temperature deviates from a predetermined target.

An aerosol delivery device is provided that includes a power source, a heating element, a switch coupled to and between the power source and the heating element, and processing circuitry coupled to the switch. The processing circuitry outputs a PWM signal during a heating time period to cause the switch to switchably connect and disconnect the output voltage to the heating element to power the heating element. The processing circuitry outputs a pulse of known current to the heating element, and measure voltage across the heating element, between adjacent pulses of the PWM signal. And the processing circuitry calculates the resistance of the heating element based on the known current and the voltage, calculates the temperature of the heating element based on the resistance, and adjusts a duty cycle of the PWM signal when the temperature deviates from a predetermined target.

A control apparatus for controlling a motor performing pressure control includes circuitry which calculates a detected speed of a motor based on an input pressure command, sensor reaction force, movable part viscous damping force and movable part mass, outputs the detected speed, calculates the movable part viscous damping force by multiplying the detected speed by a movable part viscous damping coefficient to calculate the detected speed, calculates a detected position of the motor by integrating the detected speed, outputs the detected position, calculates a sensor viscous damping pressure by multiplying the detected speed by a sensor viscous damping coefficient, calculates a sensor spring pressure by multiplying the detected position by a sensor spring constant, calculates a detected pressure of a pressure sensor by adding the sensor spring pressure to the sensor viscous damping pressure, and outputs the sensor reaction force which is the detected pressure to calculate the detected speed.

Described embodiments provide circuits, systems and methods for digitally demodulating a pulse-width modulated (PWM) signal in a motor control system. An electronic circuit of the motor control system includes an input to receive a speed demand signal that is a PWM signal having a duty cycle associated with a requested speed of a motor. A PWM demodulator demodulates the PWM signal and generates an N-bit digital speed value representative of the requested speed of the motor, where N is a positive integer. A motor driver generates, based at least in part upon the N-bit digital speed value, one or more control signals to operate the motor.

Methods and systems for operating a gas turbine engine in a multi-engine aircraft are described. The method comprises operating the gas turbine engine in a standby mode to provide substantially no motive power to the aircraft when another engine of the multi-engine aircraft is operated in an active mode to provide motive power to the aircraft, transitioning the gas turbine engine from the standby mode to the non-standby mode, and applying pulse width modulation to an air switching system of the gas turbine engine while transitioning the gas turbine engine from the standby mode to the non-standby mode.

Methods and systems for operating a gas turbine engine in a multi-engine aircraft are described. The method comprises operating the gas turbine engine in a standby mode to provide substantially no motive power to the aircraft when another engine of the multi-engine aircraft is operated in an active mode to provide motive power to the aircraft, transitioning the gas turbine engine from the standby mode to the non-standby mode, and applying pulse width modulation to an air switching system of the gas turbine engine while transitioning the gas turbine engine from the standby mode to the non-standby mode.

A motor drive apparatus driving a motor as a three-phase motor converting direct power into three-phase alternating power, includes: inverter modules equivalent in number to phases of the motor; and a control unit generating PWM signals used to drive the inverter modules with PWM. The inverter modules each include a plurality of switching element pairs connected in parallel, each of the switching element pairs including two switching elements connected in series.

Platforms and techniques are provided for controlling a power inverter using space vector pulse width modulation (PWM) operation. The inverter converts a direct voltage (DC) power source to an alternating voltage (AC) output by controlling a set of three phase switches. A bootstrap capacitor is coupled to each switch. When each switch in the set of three phase switches is in a zero state, the coupled bootstrap capacitor can charge from the current delivered in a corresponding pulse width modulation (PWM) signal. The bootstrap capacitor can deliver stored power when a one (high) switch state is entered. Each switch can be maintained at a zero state, and thus charge the bootstrap capacitor, for at least two consecutive segments of the PWM cycle. Pre-charging of the bootstrap capacitor is ensured before power delivery is required.

Motor drives, methods and estimation systems are presented for estimating a rotor position of a motor load in which four sets of inverter output current samples obtained at four different sample times in a given inverter PWM cycle are converted into a corresponding stationary reference frame current value pairs, and the rotor position estimate is computed according to the stationary reference frame current values.