A power supply including: an AC input power connector; an AC-DC converter circuit coupled to the AC input power connector; a constant-current constant-voltage control unit configured to receive DC power from the AC-DC converter circuit; a light emitting diode (LED) lamp unit configured to receive power from the constant-current constant-voltage control unit; and a capacitor coupled in parallel with the LED lamp unit.

Disclosed are an inverter control device and method. The method according to an embodiment of the present includes estimating a rotation speed of a motor, determining a slip frequency reference using an energy of a direct current terminal capacitor of an inverter, which provides an output voltage to the motor, and a direct current terminal energy reference when a direct current terminal voltage of the inverter is a certain level or less, and providing a frequency reference determined by adding the rotation speed of the motor and the slip frequency reference to the inverter.

This application provides example circuit modules and example electronic devices comprising the circuit module. One example circuit module includes a power input terminal, a power output terminal, a first switching transistor, a second switching transistor, a comparison unit, a boost unit, an energy storage unit, and a direct current conversion unit, where the first switching transistor is turned on and the second switching transistor is cut off when a source voltage input by the power input terminal to the comparison unit is greater than the preset threshold, or the first switching transistor is cut off and the second switching transistor is turned on when a source voltage input by the power input terminal to the comparison unit is less than or equal to the preset threshold.

A constant on time converter control circuit and a constant on time converter are provided. The constant on time converter control circuit comprises an error amplifier, a voltage to current converter, and an initial current source. The error amplifier is for receiving a reference voltage signal and a feedback voltage signal and outputting a compensated voltage signal. The voltage to current converter receives the compensated voltage signal and outputs a converted current signal. The initial current source provides an initial current signal. The initial current signal and the converted current signal form a new reference voltage signal. A constant on time OFF time comparator receives the new reference voltage signal and the feedback voltage signal and outputs a control signal. The control signal affects the turning on and turning off of electronic switches to produce an output voltage of a constant on time converter.

A dual-input power conversion system includes a first primary side power network comprising a first hold-up capacitor, wherein the first primary side power network has inputs configured to be coupled to a first power source, and outputs coupled to a transformer, a second primary side power network comprising a second hold-up capacitor, wherein the second primary side power network has inputs configured to be coupled to a second power source, and outputs coupled to the transformer, and a secondary side power network having inputs coupled to a secondary side of the transformer, and outputs coupled to a load, wherein the first primary side power network and the second primary side power network are configured such that a voltage across one of the first hold-up capacitor and the second hold-up capacitor is maintained by a voltage reflected from the secondary side to a corresponding primary side.

A controller of a power converter is coupled to a switch assembly and configured to perform a hold-up time procedure that causes the controller to control first and second switching elements into opposite conducting states during a first period of time of a pulse cycle and into alternate opposite conducting states during a second period of time of the pulse cycle. The hold-up time procedure also causes the controller to control a first pair of synchronous rectifier switching devices into a conducting state during a third period of time overlapping less than all of the first period of time and into the conducting state during a fourth period of time overlapping less than all of the second period of time. A second pair of synchronous rectifier switching devices is controlled into a non-conducting state during the first and second periods of time.

Disclosed is a method and a control circuit. The method includes operating a buffer circuit (1) in a first operating mode or a second operating mode. Operating the buffer circuit (1) in the first operating mode includes buffering, by a capacitor parallel circuit including a first capacitor (11) and a second capacitor (12), power (Po) provided by a power source (3) and received by a load (4). Operating the buffer circuit (1) in the second operating mode includes supplying power to the load (4) by the second capacitor (12), and regulating a first voltage (Upn) across the second capacitor (12), wherein regulating the first voltage (Upn) comprises transferring charge from the first capacitor (11) to the second capacitor (12).

Disclosed is a method and a control circuit. The method includes operating a buffer circuit in a first operating mode or a second operating mode. Operating the buffer circuit in the first operating mode includes buffering, by a first capacitor of the buffer circuit, power provided by a power source and received by a load. Operating the buffer circuit in the second operating mode includes connecting a second capacitor in series with the first capacitor to form a capacitor series circuit, supplying power to the load by the capacitor series circuit, and regulating a first voltage across the capacitor series circuit. Regulating the first voltage includes transferring charge from the first capacitor to the second capacitor.

A circuit (100) for use in voltage supply for an electrical device, having a first input (111) configured for connecting with a first voltage source, a second input (121) configured for connecting with a second voltage source, and a common output (133) configured for connecting with an input of the electrical device, comprising a first voltage converter (110) with an input connected to or being the first input (111), and configured to provide DC voltage at a first voltage level (V.sub.1) at an output (113), further comprising a second voltage converter (120) with an input connected to or being the second input (121), and configured to provide DC voltage at a second voltage level (V.sub.2) at an output (123), wherein the second voltage converter (120) is configured not to operate when a voltage level present at its output (123) is higher than a stop threshold, and to operate when a voltage level present at its output (123) is lower than a start threshold, the stop threshold is equal to or higher than the second voltage level (V.sub.2) and lower than the first voltage level (V.sub.1), and the start threshold is equal to or lower than the second voltage level (V.sub.2).

A power supply comprising a first-stage capacitor configured to provide energy to a second stage power converter. An energy transfer element coupled to the first-stage capacitor. A reservoir capacitor coupled to the energy transfer element. The reservoir capacitor is configured to receive charge from the energy transfer element. A power switch configured to control a transfer of energy from an input of the power supply to the first-stage capacitor. A controller coupled to the power switch, the controller configured to generate a hold-up signal in response to the input of the power supply falling below a threshold voltage. A charge circuit comprising a first switch and a second switch configured to be controlled by the hold-up signal. The first switch couples the reservoir capacitor to an input of the energy transfer element. The second switch is configured to uncouple the reservoir capacitor from receiving charge from the energy transfer element.