Novel voltage converter circuits are provided which step-up very low DC input voltages to higher voltages capable of supporting low-power loads. According to embodiments, a voltage step-up power converter circuit may be formed of an oscillator sub-circuit which receives a DC voltage and outputs an AC voltage; a voltage doubler sub-circuit which receives the AC voltage and outputs an augmented AC voltage; and a voltage step-up converter sub-circuit which receives the augmented AC voltage, as a control voltage, and the initial DC voltage and outputs a voltage which is more than the initial DC voltage. These circuits allow electrical energy to be harvested from very low voltage sources and to convert it as efficiently as possible to run a load.

A self-oscillating converter includes a power transistor coupled to a primary winding for controlling current flow in the primary winding, and a turn-on circuit configured to turn on the power transistor for maintaining oscillation in the self-oscillating converter. The self-oscillating converter also includes a turn-off circuit configured to turn off the power transistor to maintain an on-time of the power transistor at a pre-set value for power factor correction, and modulate the on-time of the power transistor to regulate the output current in the load device.

An electromagnetic charge-sensitive electric mosquito swatter, comprising a charging-discharging circuit (1), a boost circuit (3) and a central control circuit (4). The charging-discharging circuit (1) provides required power to the boost circuit (3). Also comprised are an electromagnetic charge space scanning circuit (5) and a gate circuit (6); the gate circuit (6) is bridged between the electromagnetic charge space scanning circuit (5) and the central control circuit (4) so that when the electromagnetic charge space scanning circuit (5) senses a holding signal of a human hand holding the swatter, the holding signal is converted into a startup signal by means of the gate circuit (6) and is transmitted to the central control circuit (4); and the central control circuit (4) drives the charging-discharging circuit (1) to provide power to the boost circuit (3). The present mosquito swatter has the advantages of being convenient and safe to use and being effective in shocking mosquitos.

A connection device for charging a battery device on a vehicle has an alternating current (AC) interface for receiving an AC plug and a direct current (DC) interface for receiving a DC plug. The DC interface has a cover flap mounted movably between a closed position that covers the DC interface and an open position that exposes the DC interface. The direct current interface has a latching mechanism with a latching means on the cover flap. The latching means locks with a mating latching means of the cover flap when in the open position. The mating latching means has an actuating section with which the DC plug makes a contact thereby unlocking the latching means of the latching mechanism when the DC plug is received in the DC interface.

A primary controller applied to a primary side of a power converter includes a current compensation circuit and a compensation voltage generation circuit. The current compensation circuit is used for generating a compensation current to a sensing resistor of the primary side according to a direct voltage and an auxiliary voltage, wherein the auxiliary voltage corresponds to an output voltage of a secondary side of the power converter, and the compensation current changes a peak voltage of the primary side. The compensation voltage generation circuit is used for generating a compensation voltage according to a reference current, a discharge time of the secondary side, and a peak current, wherein the reference current is changed with the output voltage. The compensation current and the reference current are used for making an output current of the secondary side of the power converter not be changed with the output voltage.

The present invention discloses a large-current power supply and a constant-current control method and system thereof. The large-current power supply provided by the present invention includes: a primary power supply, an energy-feedback circuit and a direct-current (DC) large-current generator; the energy-feedback circuit includes a freewheel diode and a magnetic reset winding; and a secondary coil of the DC large-current generator is connected to a load. Without an output rectifier diode and a filter capacitor at a load end of the large-current power supply provided by the present invention, the power consumption problem of the output rectifier diode at a large current is unnecessarily considered, and an electrolytic capacitor does not need to be used for filtration; and therefore, the service life of the power supply is greatly prolonged, a larger current is output easily by extending, and the power supply has the advantages of simple circuit, small size, easy control and high working reliability. By adopting the control method and system provided by the present invention, an output voltage of a Buck circuit in the primary power supply can be accurately controlled, and thus the large-current power supply obtains a constant output current at the load end.

Disclosed is a system and method for large-current power supply and constant-current control. Large-current power supply includes: primary power supply, energy-feedback circuit and direct-current (DC) large-current generator; energy-feedback circuit includes freewheel diode and magnetic reset winding; and secondary coil of DC large-current generator is connected to load. Without output rectifier diode and filter capacitor at load end of large-current power supply provided herein, power consumption problem of output rectifier diode at large current is unnecessarily considered, and electrolytic capacitor is not needed for filtration; and therefore, service life of power supply is greatly prolonged, larger current is output by extending, and power supply has advantages of simple circuit, small size, easy control and high working reliability. By adopting control method and system provided herein, an output voltage of Buck circuit in primary power supply is accurately controlled, and thus large-current power supply obtains a constant output current at load end.

The invention relates to a connection device (10) for charging a battery device on a vehicle, having an electrical alternating current interface (20) for receiving an alternating current connector and a direct current interface (30) for receiving a direct current connector (130), wherein the direct current interface (30) has a cover flap (40) which is mounted movably between a closed position (SP) which covers the direct current interface (30) and an open position (FP) which exposes the direct current interface (30). According to the invention, the direct current interface (30) has a catch mechanism (50) with a catch means (52) on the cover flap (40), said catch means locking with a mating catch means (54) of the cover flap (40) when in the open position (FP), wherein the mating catch means (54) has an actuating section (56) with which the direct current connector (130) makes contact and which unlocks the catch device (50) when the direct current connector is received in the direct current interface (30).

A DC-to-AC inverter provides an AC voltage to the primary winding of an output isolation transformer having at least one secondary winding. An AC output voltage from the secondary winding is rectified to generate a DC voltage, which is applied to a load. The magnitude of a current flowing through the load is sensed and compared to a reference magnitude to produce a feedback signal. The feedback signal controls a voltage superposition circuit, which produces a superposition voltage. The superposition voltage is applied to an input node of a current control circuit. The current control circuit responds to the superposition voltage to vary a magnitude of a control current to a switching controller in the DC to-AC inverter. The switching controller is responsive to the control current magnitude to vary the frequency of the AC voltage and to thereby vary the load current.

An electric drive system includes bus rails carrying a bus voltage, an energy storage system (ESS), and a power inverter. The system includes a voltage converter connected to the bus rails and having an inductor coil, semiconductor switches, a bypass switch connected to a positive bus rail, and a capacitor. A polyphase electric machine is electrically connected to the power inverter. A controller executes a method in which operation of the converter is regulated based on power, torque, and speed values of the electric machine. The converter is selectively bypassed by closing the bypass switch under predetermined high-power/high-torque conditions, with the bus voltage adjusted until it is equal to the battery output voltage. The bypass switch is opened and the bus voltage thereafter regulated to a predetermined voltage.