In one embodiment, a power factor correction (PFC) circuit can include: (i) a rectifier bridge and a PFC converter coupled to an input capacitor; (ii) a harmonic wave compensation circuit configured to shift a phase of a DC input voltage provided from the rectifier bridge, where the harmonic wave compensation circuit comprises a phase of about −45° when a corner frequency is about 50 Hz; and (iii) a PFC control circuit configured to control the PFC converter, where the PFC control circuit comprises a first sampling voltage, and the harmonic wave compensation circuit is configured to control a phase of the first sampling voltage to lag a phase of the DC input voltage by about 45°.

Embodiments of the present invention provide a power supply module and a soft start method. The power supply module includes an input detection circuit configured to output a first notification signal to a trigger drive circuit when it is determined that the power supply module receives a power supply signal; the trigger drive circuit configured to, upon receipt of the first notification signal sent from the input detection circuit, wait for a predetermined duration without sending a drive signal to a current limiting circuit, and to send the driver signal to the current limiting circuit when the predetermined duration elapses; and the current limiting circuit configured to limit a current on a Direct Current (DC) bus of the power supply module when the drive signal is not received by the current limiting circuit, and not to limit the current on the DC bus upon receipt of the drive signal.

Embodiments of the present invention provide a power supply module and a soft start method. The power supply module includes an input detection circuit configured to output a first notification signal to a trigger drive circuit when it is determined that the power supply module receives a power supply signal; the trigger drive circuit configured to, upon receipt of the first notification signal sent from the input detection circuit, wait for a predetermined duration without sending a drive signal to a current limiting circuit, and to send the driver signal to the current limiting circuit when the predetermined duration elapses; and the current limiting circuit configured to limit a current on a Direct Current (DC) bus of the power supply module when the drive signal is not received by the current limiting circuit, and not to limit the current on the DC bus upon receipt of the drive signal.

A power factor correction device comprises a power stage circuit converting input alternating current voltage into input current according to a pulse width modulation signal and outputs the input current to a load generating output voltage on the load, and sampling the input current outputting a correcting current; a current compensating circuit receiving and comparing the correcting current with a reference current signal generating a compensating current signal; a voltage compensating circuit receiving and comparing the output voltage with a reference voltage generating a compensating voltage signal; a multiplication amplifier receiving the compensating current signal and the compensating voltage signal generating an updated reference current signal by multiplying the compensating current signal with the compensating voltage signal; and a pulse width modulation converter receiving the compensating current signal and the compensating voltage signal generating the pulse width modulation signal to synchronize phase of alternating current voltage and input current.

A connection box with reliable and yet inexpensive contacts for solar panels to enable the use of multiple types of passive and active covers for different functionalities in the junction box built into the panel.

A connection box with reliable and yet inexpensive contacts for solar panels to enable the use of multiple types of passive and active covers for different functionalities in the junction box built into the panel.

An electrical safety system comprises a main safety device including a N-type transistor and an auxiliary safety device including a P-type transistor, alternately activated under command of a controller. The N-type transistor and the P-type transistor have the function of overcurrent protection, respectively in a first operating mode and in a second operating mode. The auxiliary safety device includes a passive component, connected in series with the P-type transistor, for providing a voltage drop when a current passes through the passive component, and a driving circuit for turning off the P-type transistor under control of the voltage drop exceeding a first threshold, in the second operating mode.

A voltage detector operates to detect a system power supply voltage and generate a trigger signal. A control signal generator responds to the trigger signal and generates a control signal. A DC bias generator responds to the control signal by generating a DC bias. The control signal controls the DC bias to have a first value when the power supply voltage is a first voltage and have a second value when the power supply voltage is a second voltage different from the first voltage, wherein the first value is different from the second value. A dynamic DC bias is generated which can not only support a larger voltage scope, but also significantly improves signal to noise ratio. The system power supply detection may concern stop/start operation of an automobile engine.

A voltage detector operates to detect a system power supply voltage and generate a trigger signal. A control signal generator responds to the trigger signal and generates a control signal. A DC bias generator responds to the control signal by generating a DC bias. The control signal controls the DC bias to have a first value when the power supply voltage is a first voltage and have a second value when the power supply voltage is a second voltage different from the first voltage, wherein the first value is different from the second value. A dynamic DC bias is generated which can not only support a larger voltage scope, but also significantly improves signal to noise ratio. The system power supply detection may concern stop/start operation of an automobile engine.

A voltage control system includes a first voltage converter, a second voltage converter and a voltage monitoring module. The first voltage converter is coupled to a first power source and configured to convert first electrical energy of the first power source into a first output voltage. The second voltage converter is coupled to a second power source and configured to convert second electrical energy of the second power source into a second output voltage. The voltage monitoring module is coupled to the first voltage converter and the second voltage converter. The voltage monitoring module is configured to regulate the first output voltage or the second output voltage by controlling the first voltage converter and the second voltage converter according to the first output voltage and the second output voltage.