A power converter including: a dual output resonant converter including a first output, a second output, a common mode control input, and a differential mode control input, wherein a voltage/current at the first output and a voltage/current at the second output are controlled in response to a common mode control signal received at the common mode control input and a differential mode control signal received at the differential mode control input; and a dual output controller including a first error signal input, a second error signal input, a delta power signal input, a common mode control output, and a differential mode control output, wherein the dual output controller is configured to generate the common mode control signal and the differential mode control signal in response to a first error signal received at the first error signal input and a second error signal received at the second error signal input, wherein the first error signal is a function of the voltage/current at the first output and the second error signal is a function of the voltage/current at the second output, and wherein the common mode control signal is output from the common mode control output and the differential mode control signal is output from the differential mode control output, wherein the differential mode signal is limited by a differential mode signal limiting circuit.

A light emitting load driving device includes a first constant current source structured to be serially connected to a first light emitting load group; a second constant current source structured to be serially connected to a second light emitting load group; a first load connection terminal structured to be connected to the first light emitting load group; a second load connection terminal structured to be connected to the second light emitting load group; and a control circuit structured to be supplied a first voltage applied to the first load connection terminal, a second voltage applied to the second load connection terminal, and a reference voltage applied to the control circuit, wherein the control circuit is structured to select a minimum voltage between the first voltage and the second voltage, and the control circuit is structured to equalize the minimum voltage and the reference voltage.

Reverse currents are prevented using existing components, like a primary-side current transformer. A power supply includes an isolation transformer, a switch, a synchronous rectifier, a smoother, a controller with a signal generator circuit that outputs main drive signals for main switching elements of the switch and drive signals for synchronous rectifier elements of the synchronous rectifier, and a current detector that has a current transformer, detects a current flowing to the switch, and outputs an output current detection signal. The controller includes an OR circuit that generates an OR signal for the main drive signals and a reverse current determination circuit that determines whether a reverse current has occurred based on the OR signal and the output current detection signal. When the occurrence of a reverse current has been determined, outputting of the main drive signals and the drive signals is stopped.

The present application is directed to a display device and an over-voltage protection method. As an example, the display device includes a power source assembly and an electric load. The power source assembly includes an LLC circuit, a transformer and a feedback circuit. An input end of the transformer is connected with a control end of the LLC circuit, a first output end of the transformer is connected with a supply end of the LLC circuit, a second output end of the transformer is connected with the electric load, and the transformer is configured to supply power to the LLC circuit and the electric load. A first end of the feedback circuit is connected with the second output end of the transformer, a second end of the feedback circuit is connected with the feedback end of the LLC circuit and the feedback circuit is configured to supply a voltage derived from the second output end of the transformer to the LLC circuit. The LLC circuit is configured to stabilize a voltage supplied by the second output end of the transformer to the electric load based on the feedback voltage supplied by the feedback circuit.

A power converter including: a dual output resonant converter including a first output, a second output, a common mode control input, and a differential mode control input, wherein a voltage/current at the first output and a voltage/current at the second output are controlled in response to a common mode control signal received at the common mode control input and a differential mode control signal received at the differential mode control input; and a dual output controller including a first error signal input, a second error signal input, a delta power signal input, a common mode control output, and a differential mode control output, wherein the dual output controller is configured to generate the common mode control signal and the differential mode control signal in response to a first error signal received at the first error signal input and a second error signal received at the second error signal input, wherein the first error signal is a function of the voltage/current at the first output and the second error signal is a function of the voltage/current at the second output, and wherein the common mode control signal is output from the common mode control output and the differential mode control signal is output from the differential mode control output, wherein the differential mode signal is limited by a differential mode signal limiting circuit.

Provided is a DC power supply device If an electrical tool (81) of a rated voltage of 36 V is connected to the DC power supply device (1) (if the voltage of a lower positive terminal indicates the presence of a short bar), a microcomputer (30) performs control so as to switch a switching element (Q1) on and output a DC voltage of 36 V between an upper positive terminal and the upper negative terminal. If an electrical tool (81) of a rated voltage of 18 V is connected to the DC power supply device (1) (if the voltage of the lower positive terminal indicates the absence of a short bar), the microcomputer (30) performs control so as to switch a switching element (Q2) on and output a DC voltage of 18 V between the upper positive terminal and the upper negative terminal.

A controller for use with a power converter and a power switch comprising a primary controller and a secondary controller. The primary controller to control the power switch to transfer energy from the input side to the output side of the power converter. The secondary controller to transmit a control signal to the primary controller through a communication link, and to initiate a transition operation with the primary controller through the communication link. The secondary controller comprises a secondary switch control circuit configured to output the control signal in response to an output of the power converter, a charging circuit coupled to an energy storage element for providing power to the secondary control circuit, and a voltage detection circuit coupled to the energy storage element, wherein the voltage detection circuit is configured to indicate to the secondary switch control circuit when to initiate the transition operation.

An isolator circuit according to the present invention includes a first isolator, an AD converter, and a second isolator. The first isolator is configured to galvanically isolate a first terminal and a second terminal from each other. The first isolator receives an input pulse signal and outputs an output pulse signal to the second terminal. The AD converter is configured to output a digital signal corresponding to a duty ratio of the output pulse signal. The second isolator is configured to galvanically isolate the second terminal and the third terminal from each other. The second isolator is configured to receive the digital signal and outputs a feedback pulse signal to the third terminal.

A light emitting load driving device includes a plurality of constant current sources structured to be serially connected to a plurality of light emitting loads connected in parallel respectively, and structured to control a current flowing through the plurality of light emitting loads connected in parallel; a plurality of load connection terminals structured to be connected to the plurality of light emitting loads connected in parallel and the plurality of constant current sources respectively; a control circuit structured to be controlled based on a plurality of terminal voltage applied to the plurality of load connection terminals and a reference voltage, and structured to control a voltage output portion generating an output voltage provided to the plurality of light emitting loads connected in parallel so that both of a lowest terminal voltage applied to the plurality of load connection terminals and the reference voltage are equalized with respect to each other.

A load control device for controlling the amount of power delivered to an electrical load (e.g., an LED light source) includes first and second semiconductor switches, a transformer, a capacitor, a controller, and a current sense circuit operable to receive a sense voltage representative of a primary current conducting through to a primary winding of the transformer. The primary winding is coupled in series with a semiconductor switch, while a secondary winding is adapted to be operatively coupled to the load. The capacitor is electrically coupled between the junction of the first and second semiconductor switches and the primary winding. The current sense circuit receives a sense voltage and averages the sense voltage when the first semiconductor switch is conductive, so as to generate a load current control signal that is representative of a real component of a load current conducted through the load.