摘要:
Exemplary embodiments are directed to a power controller. A method may include comparing a summation voltage comprising a sum of an amplified error voltage and a reference voltage with an estimated voltage to generate a comparator output signal. The method may also include generating a gate drive signal from the comparator output signal and filtering a signal coupled to a power stage to generate the estimated voltage.
摘要:
Exemplary embodiments are directed to a power controller. A method may include comparing a summation voltage comprising a sum of an amplified error voltage and a reference voltage with an estimated voltage to generate a comparator output signal. The method may also include generating a gate drive signal from the comparator output signal and filtering a signal coupled to a power stage to generate the estimated voltage.
摘要:
A circuit converts an input voltage to an output voltage. The circuit includes a first stage voltage converter that receives the input voltage and converts the input voltage. The first stage voltage converter includes a first buck converter having a double rail output: a first rail at a high intermediate voltage and a second rail at a low intermediate voltage. The circuit also includes a second stage voltage converter that receives the output rails and produces the output voltage.
摘要:
A circuit converts an input voltage to an output voltage. The circuit includes a first stage voltage converter that receives the input voltage and converts the input voltage. The first stage voltage converter includes a first buck converter having a double rail output: a first rail at a high intermediate voltage and a second rail at a low intermediate voltage. The circuit also includes a second stage voltage converter that receives the output rails and produces the output voltage.
摘要:
Systems, methods and apparatus are disclosed for wireless power transfer using multiple receive coils. In one aspect a wireless power receiver is provided that is configured to receive wireless power from a wireless power transmit coil. The wireless power receiver includes a first receive coil having a first mutual coupling with the transmit coil. The wireless power receiver further includes a second receive coil having a second mutual coupling with the transmit coil. The wireless power receiver further includes a load coupled to at least one of the first receive coil and the second receive coil for receiving the wireless power.
摘要:
Exemplary embodiments are directed to detection and validation of wirelessly chargeable devices positioned within a charging region of a wireless power transmitter. A device may include a wireless power transmitter configured detect a change in at least one parameter at the transmitter. The transmitter may further be configured to determine whether at least one valid chargeable device is positioned within a charging region of the transmitter upon detecting the change in the at least one parameter.
摘要:
Exemplary embodiments are directed to variable power wireless power transmission. A method may include conveying wireless power to a device at a first power level during a time period. The method may further include conveying wireless power to one or more other devices at a second, different power level during another time period.
摘要:
A circuit for operating a polyphase DC motor, such as the type having a plurality of "Y" connected stator coils, has circuitry for charging the coils at a rate which will reduce EMI and other noise, while maintaining an acceptable charge rate. The gate of a selected high side driving transistor is charged at a relatively high rate during a ramping phase. During the ramping phase, the gates of the selected transistor is charged to a voltage near the voltage needed to form a channel in the transistor for conduction. After the ramping phase, the gates are charged at a lesser rate in order to control the rate of charging of the stator coils to prevent noise.
摘要:
A circuit for operating a polyphase dc motor that has a plurality of driving coils has circuitry for receiving the back emf of at least one of the driving coils at a time when the at least one of the driving coils is in a floating state prior to the desired commutation sequence. Circuitry is provided for determining an anticipated direction the back emf will cross a reference voltage based upon the desired commutation sequence. And circuitry is also provided for determining if the back emf received by the circuitry for receiving the back emf crosses a reference voltage from other than the anticipated direction.In addition, a method for operating a polyphase dc motor having a plurality of driving coils includes determining the actual instantaneous position of the rotor of the motor by determining when the back emf of at least one coil at a time when the at least one coil is in a floating state prior to the desired commutation sequence crosses a reference voltage from a predetermined direction. A desired rotor position precedent to executing a desired commutation sequence is determined, and the desired commutation sequence is executed when the circuit for determining the actual instantaneous position of the rotor detects that the rotor is actually in the desired rotor position. A signal is generated if the back emf of the at least one coil in a floating state crosses the reference voltage from other than the predetermined direction.
摘要:
A kelvin current sensing circuit in an integrated control circuit that controls the current flowing through the driving coils of a polyphase DC motor. The invention provides for adjusting the voltage to the lower driver transistors of the control circuit by having the kelvin current sensing occur internally within the chip. A ground compatible differential amplifier circuit is used in one embodiment. Each of the lower transistors are connected to the base of respective PNP transistors, the emitters of which being connected together to control one side of the differential amplifier. A control voltage is applied to the other side of the differential amplifier. The output of a comparator, that is connected to the differential amplifier, is used to control the operation of the lower driver transistors. Therefore all of the sensing is done internally in the semiconductor chip. The voltages are taken at the source of each of the lower transistors. This eliminates the parasitic resistances associated with the connection between the transistors and the sense resistor attached externally to the device. Since the kelvin current sensing is done internally, the pin which connected the inverting input of the comparator to the sensing resistor has been eliminated.