Abstract: The present invention relates to a charge equalization apparatus, which can enable the primary windings and the secondary windings of transformers to be easily manufactured, can control the flow of charges into batteries depending on the charged states of series-connected batteries, and can prevent overcurrent from flowing into batteries that are currently being charged.

Abstract: A phase shift full bridge converter with a reduced current stress includes: a switching unit that switches an input voltage; a transformer that includes a first capacitor serially connected to, and having a primary side and a secondary side; an auxiliary circuit unit that includes a first switch, a second switch, and a second capacitor, which are connected in parallel to the secondary side of the transformer; and a rectification unit that is connected to the auxiliary circuit unit, with an output inductor being removed.

Abstract: The present invention relates, in general, to a charge equalization apparatus with series-connected battery cells and, more particularly, to a charge equalization apparatus, in which series-connected battery cells (B1 to BN) are connected in parallel with the primary windings (Mi 1 to M1N) of transformers (T1 to TN), switches (S1 to SN) for controlling the flow of current of the primary windings are connected in series with the primary windings (M1 1 to M1N), and multiple secondary windings (M21 to M2N) corresponding to the primary windings are connected in parallel with each other.

Abstract: The present invention relates, in general, to a battery voltage equalization apparatus and method, and, more particularly, to a charge equalization apparatus and method, which decrease the withstand voltages of semiconductor switching elements while maintaining charge equalization performance, thus making it easy to implement the secondary windings of transformers while reducing the costs of the charge equalization apparatus. The charge equalization apparatus includes N first transformers (T1 to Tn) connected in series with N series-connected batteries (B1 to Bn) and adapted to decrease voltages of overcharged batteries among the N batteries. A charge storage device (Cdump) stores energy supplied from the first transformers. A second transformer (TS) redistributes energy stored in the charge storage device to the N series-connected batteries.

Abstract: The present invention relates to a charge equalization apparatus, which allows the primary and secondary windings of a transformer to be easily fabricated, can control the flow of charge to batteries depending on the charged states of series-connected batteries, and can prevent overcurrent from flowing into a battery currently being charged.

Abstract: There is provided a transformer improved in leakage inductance including: a core having first, second and third legs electromagnetically coupled to one another; a primary winding formed of a conductor having one end and another end receiving power from the outside and dividedly wound around the first, second and third legs; and a secondary winding wound around at least one of the first, second and third legs and receiving induced power by electromagnetic induction with the primary winding.

Abstract: A direct current (DC) power supply for varying an output voltage according to a load current variation is disclosed. The DC power supply includes an alternating current(AC)/DC conversion unit converting commercial AC power into DC power, a DC/DC conversion unit converting a voltage level of the DC power and outputting output power, and a control unit controlling conversion of the voltage level of the fed-back DC power according to a variation in a load current of the output power from the DC/DC conversion unit.

Abstract: A soft start circuit is connected to a pulse width modulation controller including an oscillator, and a functionality of modulating amplitude to a pulse width and a power supply includes the soft start circuit. The soft start circuit includes a frequency controlling unit, a duty ratio establishing unit, and a variable switching unit. The frequency controlling unit generates first and second parameter signals for determining a frequency signal frequency by a power source from the PWM controller and provides them to the PWM controller. The duty ratio establishing unit generates a third parameter for determining amplitude of the frequency signal generated by the PWM controller according to a reference voltage, and provides it to the PWM controller. The variable switching unit determines whether it is a first predetermined time from a start-up state, and controls the first parameter of the frequency controller during the first predetermined time.

Abstract: An asymmetrical DC to DC converter using one or more NAND gates. In one embodiment, an asymmetrical DC to DC converter includes a converter unit including a switching unit and adapted to transform a first voltage having a first level to a second voltage having a second level according to a switching operation of the switching unit and an output voltage control unit including at least one NAND gate and adapted to control the second level of the second voltage to be substantially uniform. The output voltage control unit is further adapted to generate a driving signal for the switching unit via the at least one NAND gate. As such, an asymmetrical control circuit that is suitable for an asymmetrical half bridge converter or an active clamp converter can be simply and inexpensively realized using a NAND gate instead of using expensive dedicated chips.