High power switching power supply

DETAILED DESCRIPTION The present invention is intended to provide an SPS having a high output power and high efficiency.
This is accomplished by successively applying voltages of opposite polarities across primary of a power transformer, wherein only two transistors are used.
The input voltage may be AC or DC.
Only one input capacitor is employed.
Another capacitor stores a DC voltage.
In one embodiment the DC voltage is substantially equal half the input voltage, wherein the capacitor may have a small value.
In another embodiment the DC voltage has an opposite polarity to the input voltage in order to effectively increase it.
The primary is coupled to ground so that transformer current, including short circuit current, can be easy monitored.
In one embodiment the SPS converts input signal into output signal and comprises a node, a switching means for alternatively coupling the node to the input signal or ground, a capacitive means for storing a DC voltage, and an inductive means for providing the output signal, wherein the capacitive and inductive means are coupled in series between the node and ground.
SPS according to the present invention converts input voltage into output signal and comprises a node, a capacitive means coupled to ground for storing a DC voltage having an opposite polarity to the input voltage, a switching means for alternatively coupling the node to the input voltage or DC voltage, an inductive means coupled to the node and ground for providing a charging signal and the output signal, and a rectifying means for applying the charging signal to the capacitive means.