Power converter possessing zero-voltage switching and output isolation
First Claim
1. A power converter circuit for converting a voltage level across a power and a common terminal of a voltage source to a different voltage level when supplying a load, the circuit comprising:
- an input choke having an input and an output terminal, said input terminal being connected to the power terminal of the voltage source;
a main switching means comprising a first switch and a parallel connected diode between the output terminal of the choke and the common terminal for selectively establishing a current through said choke from said voltage source;
a transformer having a primary and a secondary winding, said primary winding having a first and a second input terminal, said first input terminal being connected to said output terminal of said choke;
a secondary switching means connected between the second input terminal of the transformer and the common terminal for selectively establishing a current through said transformer primary winding, said secondary switching means comprising a parallel combination of a capacitor, a diode and a second switch connected between said second input terminal and the common terminal;
a diode connected in series between said transformer secondary winding and the load;
an output capacitor connected in parallel with said load; and
means for complementarily enabling and disabling said main and said secondary switching means to control current through the transformer primary winding.
2 Assignments
0 Petitions
Accused Products
Abstract
A modified boost converter accomplishes power transfer to a load with an electrical isolation, a zero-voltage and a zero-current switching, a transformer core resetting mechanism, and component stresses identical to those in the conventional boost converters. The power converter contains two switching devices, a main one connected in parallel and a secondary one connected in series with a transformer primary winding. A secondary winding of the transformer is connected through an output rectifier to the load. Zero-voltage switching and proper transformer-core resetting are achieved from the resonance that exists between the parasitic capacitance of the secondary switching device and the magnetization inductance of the transformer. A transformer leakage inductance facilitates zero-current switching; thus, reducing the recovery time and current in the output rectifier, and the turn-on switching loss in the conventional main switching device. The switching converter contains a lossless clamping circuit, to limit the voltage stresses across both of the power switching devices to the reflected output voltage appearing across the primary.
-
Citations
10 Claims
-
1. A power converter circuit for converting a voltage level across a power and a common terminal of a voltage source to a different voltage level when supplying a load, the circuit comprising:
-
an input choke having an input and an output terminal, said input terminal being connected to the power terminal of the voltage source; a main switching means comprising a first switch and a parallel connected diode between the output terminal of the choke and the common terminal for selectively establishing a current through said choke from said voltage source; a transformer having a primary and a secondary winding, said primary winding having a first and a second input terminal, said first input terminal being connected to said output terminal of said choke; a secondary switching means connected between the second input terminal of the transformer and the common terminal for selectively establishing a current through said transformer primary winding, said secondary switching means comprising a parallel combination of a capacitor, a diode and a second switch connected between said second input terminal and the common terminal; a diode connected in series between said transformer secondary winding and the load; an output capacitor connected in parallel with said load; and means for complementarily enabling and disabling said main and said secondary switching means to control current through the transformer primary winding. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A power converter for providing a regulated DC output from an unregulated DC voltage source, the voltage source having a pair of output terminals of relatively positive and negative polarity, the power converter comprising:
-
an input choke having an input terminal and an output terminal, said input terminal being coupled to one of the pair of output terminals of the voltage source; a first switching means coupled in circuit between said output terminal of said choke and another of the pair of output terminals of the voltage source; a single-ended transformer having a primary winding and a secondary winding, each of said primary and secondary windings having first and second end terminals, a first end terminal of said primary winding being coupled to said output terminal of said choke; a second switching means coupled in circuit between said another of the pair of output terminals of the voltage source and a second end terminal of said transformer primary winding; an output rectifier means coupled to said end terminals of said secondary winding for providing a rectified DC output; and control means coupled to each of said first and second switching means and operative to selectively gate each of said switching means into and out of conduction so as to establish an alternating magnetization current in said transformer primary winding. - View Dependent Claims (8, 9, 10)
-
Specification