Single ended, separately driven, resonant DC-DC converter

DETAILED DESCRIPTION Accordingly, an object of the present invention is to provide a DC-DC converter which ensures a stable DC-DC conversion, in which, in a DC-DC converter having a switching element inserted between a DC power source and an input terminal of a transformer, for example, a blocking oscillator with an output stabilizing means directly driven by the DC power source voltage is used as an oscillator for driving a switching circuit of the voltage resonance type.
According to the present invention, there is provided a DC-DC converter comprising: an ideal transformer with a leakage inductance and an exciting inductance in the primary winding; a capacitor connected in parallel with the exciting inductance of the ideal transformer; switching means of the voltage resonance type including a switching element connected between the primary winding of the ideal transformer and an input DC power source, the switching means periodically interrupting a voltage of the DC power source; a blocking oscillating circuit with output stabilizing means which directly receives a voltage of the input DC power source and controls the switching means by the oscillating output; and means for rectifying and smoothing the output from the secondary winding of the ideal transformer and for supplying the rectified and smoothed output to a load.
The stabilizing means of the blocking oscillating circuit including a means for individually change a pulse width and a pulse stop period of an output signal from the blocking oscillating circuit, a means for keeping the pulse width and the pulse stop period at fixed values, or a means for preventing a reaction or counter action from the switching circuit to the blocking oscillating circuit.