Power supply apparatus

摘要

There is provided a power supply apparatus capable of precisely control a primary side switching frequency at a secondary side by receiving fed-back information regarding a power state at the secondary side without a separate expensive circuit or a complicated circuit. The power supply apparatus includes: a power supplying unit having a primary side and a secondary side having different ground electrical characteristics, switching power input to the primary side, and transferring the switched power to the second side electrically insulated from the primary side to supply the power; a controlling unit provided on the secondary side and receiving fed-back information regarding a power state of the power supplying unit to control a maximum value and a minimum value of a switching frequency of the primary side; and a transferring unit transferring a control signal from the controlling unit to the primary side of the power supplying unit.

主权项

1. A power supply apparatus comprising:
a power supplying unit having a primary side and a secondary side having different ground electrical characteristics, switching an input power input to the primary side, and transferring the switched power to the second side electrically insulated from the primary side to supply an output power; a controlling unit provided on the secondary side and receiving fed-back information regarding a power state of the power supplying unit to control a maximum value and a minimum value of a switching frequency of the primary side; and a transferring unit transferring a control signal from the controlling unit provided on the secondary side to the primary side of the power supplying unit; wherein the controlling unit determines the switching frequency according to a generated maximum current and a generated minimum current, wherein the controlling unit includes:
a current generating unit generating a maximum current and a minimum current flowing in external resistors, respectively;a signal generating unit generating a pulse signal having a frequency determined according to the currents generated by the current generating unit;a monostable unit determining a timing of a signal according to the pulse signal of the signal generating unit; anda driving unit generating a switching signal controlling the switching of the switching unit according to the timing of the monostable unit, and wherein the signal generating unit includes:
a capacitor charged with the current from the current generating unit or discharging the current;a switch controlling the charging or discharging of the capacitor;a first comparator comparing a first preset reference voltage with a voltage of the capacitor to control the switching of the switch;a second comparator comparing the voltage of the capacitor with a second preset reference voltage to supply the pulse signal to the monostable unit; anda buffer buffering a switching control signal of the first comparator.