DC to DC converter

Claim 2

The converter of claim 1, wherein said filter circuit further comprises a filter inductor and a filter capacitor.

Claim 3

The converter of claim 1, wherein said switching circuit comprises two switching devices, the first switching device when closed connecting said energy storage inductance across said input voltage and said second switching device when closed connecting said energy storage inductance across said capacitance.

Claim 4

The converter of claim 3 wherein said control circuit drives said two switching devices such that (a) said first switching device is turned on while second switching device is off; (b) said first switching device is turned off and both said switching devices are off for a short dead-time interval; (c) said second switching device is turned on and said first switching device is off; (d) said second switching device is turned off and both said switching devices are off again for a short dead time interval; and (e) the process is repeated periodically.

Claim 5

The converter of claim 4 further comprising capacitance in parallel with at least one of said switching devices, so that voltage across said switching device is virtually zero prior to turning on or off.

Claim 6

The converter of claim 5 wherein said capacitance comprise self-capacitance of said electronic switching devices.

Claim 7

In a DC to DC converter having: an input voltage source; a capacitance coupled to said input voltage source; and an inductance, a method for regulating output power comprising the steps of: connecting said inductance alternatively across said input voltage source and across said capacitance via a switching circuit; full wave rectifying the resulting voltage across said inductance; filtering said rectified voltage in order to generate a DC output voltage; controlling the operation of said switching circuit for modulating said DC output voltage.

Claim 8

The method of claim 7, wherein said filtering step includes the step of providing said rectified voltage to a filter inductor and a filter capacitor.

Claim 9

The method of claim 8, wherein the step of connecting said inductance alternatively includes: coupling two switching devices across said inductance; closing the first switching device to connect said energy storage inductance across said input voltage source; and closing the second switching device to connect said energy storage inductance across said capacitance.

Claim 10

The method of claim 9, wherein said step of controlling the switching circuit includes the steps of: turning on said first switching device while said second switching device is off; turning off said first switching device while said second switching device is off for a short dead-time interval; turning on said second switching device while said first switching device is off; turning off said second switching device while said first switching device is off for a short dead time interval;and (e) repeating steps (a) through (d) periodically.

Claim 11

The method of claim 9 further comprising the step of reducing voltage across said switching devices to virtually zero prior to turning on or off by coupling capacitance in parallel with said switching devices.

Claim 12

A DC to DC converter comprising: an input voltage source; a capacitance; an output circuit; a switching circuit for connecting said output circuit alternatively across said input voltage source and said capacitance; said output circuit further comprising: an inductance coupled to the output of the switching circuit and having at least one rectifier at each end, the second terminal of said rectifiers coupled to a common point, and a capacitance and a load terminal connected across an intermediate point of said inductance and said common point.

Claim 13

The converter of claim 12, wherein said inductance comprises a first and a second inductance coupled in series forming said intermediate point.

Claim 14

A DC to DC converter comprising: an input voltage source; a capacitance; an output circuit; a switching circuit connecting said output circuit alternatively across said input voltage source and said capacitance; said output circuit further comprising: a first and second inductance coupled in series to the output of the switching circuit; a third and fourth inductance coupled in series and formed by isolation windings across said first and second inductance, said third and fourth inductance having at least one rectifier at each end for full wave rectification, the second terminal of said rectifiers coupled to a common point, and a capacitance and a load terminal connected across an intermediate point of said third and fourth inductance and said common point.

Claim 15

In a DC to DC converter an output circuit comprising: a first and second inductance coupled in series to form the first and second terminals of said output circuit; a third and fourth inductance coupled in series and formed by isolation windings across said first and second inductance, siad third and fourth inductance having at least one rectifier at each end for full wave rectification, the second terminal of said rectifier coupled to a common point, and a capacitance and a load terminal connected across an intermediate point of said third and fourth inductance and said common point.

Claim 16

The converter of any one of claims 12 to 15, wherein said first and second inductance are substantially equal in value.

Claim 17

The converter of claim 14, wherein said third and fourth inductance are substantially equal in value.

Claim 18

The converter of claim 17, wherein said inductances have substantially low magnetising inductance.

Claim 19

The converter of any one of claims 12 to 18, wherein said circuit comprises two electronic switching devices, the first switching device when closed connecting said output circuit across said input voltage source and said second switching device when closed connects said output circuit across said capacitance.

Claim 20

The converter of claim 19, wherein said switching circuit switches said two switching devices such that (a) said first switching device is turned on while said second switching device is off; (b) said first switching device is turned off and both said switching devices are off for a short dead-time interval; (c) said second switching device is turned on and said first switching device is off; (d) said second switching device is turned off and both said switching devices are off again for a short dead time interval; and (e) the process is repeated periodically.

Claim 21

The converter of claim 20 further comprising capacitance in parallel with at least one of said switching devices, so that voltage across said switching device is virtually zero prior to turning on or off.

Claim 22

The converter of claim 21 wherein said capacitance in parallel with said switching devices comprise self-capacitance of said electronic switching devices.