Converter circuit including switch element unit
View Patent ↗A converter circuit includes a transformer having primary windings and at least one secondary winding, a rectifier circuit connected to the secondary winding, and oscillating circuits connected to the primary windings. Each of the oscillating circuits has a switch element unit having no body diode.
1. A converter circuit comprising:
a transformer having a first primary winding, a second primary winding and a secondary winding;
a rectifier circuit connected between the secondary winding and a load;
a first oscillation circuit connected to a first DC power source and the first primary winding;
a second oscillation circuit connected to a second DC power source and the second primary winding; and
a control circuit configured to control the first and the second oscillation circuits,
wherein each of the first and the second oscillation circuits includes at least one switch element having no body diode,
wherein at least one of the first and the second primary windings have a number of turns which are variable, and
wherein the first and the second primary windings are configured such that a ratio n2/n1 is allowed to be selectively switched between n2/n1=Vref2/Vref1 and n2/n1>Vref2/Vref1,
where n1 and n2 are numbers of turns of the first and the second primary windings, respectively; and Vref1 and Vref2 are reference voltages of the first and the second DC power sources, respectively.
2. The converter circuit of claim 1 , wherein each of the first and the second oscillation circuits comprises two pairs of switch elements each having no body diode, the two pairs of the switch elements forming a full-bridge circuit.
3. The converter circuit of claim 1 , wherein each of the first and the second oscillation circuits comprises a pair of switch elements each having no body diode, the pair of switch elements forming a half-bridge circuit.
4. The converter circuit of claim 1 , wherein each of the first and the second oscillation circuits comprises a single switch element having no body diode.
5. The converter circuit of claim 1 , wherein each of the at least one switch elements having no body diode of each of the first and the second oscillation circuits has a lateral transistor structure comprising a GaN layer and an AlGaN layer.
6. The converter circuit of claim 5 , wherein each of the at least one switch element having no body diode of each of the first and the second oscillation circuits is a single gate transistor.
7. The converter circuit of claim 1 , wherein each of the at least one switch elements having no body diode of each of the first and the oscillation circuits is a bidirectional switch element.
8. The converter circuit of claim 1 , wherein the transformer is a flyback transformer.
9. The converter circuit of claim 1 , wherein a reverse current does not flow through each of the first and the second oscillation circuits when the at least one switch element in the corresponding oscillation circuit is turned off.