DC-DC converter and transformer
First Claim
1. A DC-DC converter comprising:
- a first transformer provided with a first core having a gap, the first core being wound around with a first core primary winding and a first core secondary winding;
a second transformer provided with a second core having a gap narrower than the gap of the first core or no gap, the second core being wound around with a second core primary winding and a second core secondary winding;
a first switching element serially connected to the first core primary winding and the second core primary winding, the first switching element being set in conducting/non -conductive state in a predetermined period;
a first rectifier element in which a first polarity terminal is connected to a first terminal of the first core secondary winding that generates an electromotive force of first polarity when the first switching element conducts, the first rectifier element being biased in a reverse bias condition;
a second rectifier element in which the first polarity terminal is connected to a second terminal of the second core secondary winding that generates an electromotive force of second polarity when the first switching element conducts, the second rectifier element being biased in a forward bias condition;
a secondary winding connection point to which a third terminal and a fourth terminal are connected, the third terminal being provided at an opposite side of the first terminal of the first core secondary winding and the fourth terminal being provided at an opposite side of the second terminal of the second core secondary winding;
a connection point which connects the secondary polarity terminal of the first rectifier element and the second polarity terminal of the second rectifier element;
a common current path in common with a current path which includes the first core secondary winding and the first rectifier element and a current path which includes the second core secondary winding and the second rectifier element, the common current path connecting the secondary winding connection point and the connection point;
an output terminal provided on the common current path; and
an output coil provided on the common current path.
1 Assignment
0 Petitions
Accused Products
Abstract
A DC-DC converter using a plurality of transformers capable of decreasing the loss, preventing heat generation of transformers, and improving the heat transfer property of the core, and an integrated type transformer used in this DC-DC converter. A terminal T1 in which a negative electromotive force is generated and a terminal TR2 in which a positive electromotive force is generated, while a switching element Q1 is conducting, are connected at a node N1. An output coil L1 and output terminals TO1 and TO2 are provided on a current route shared by transformers T1 and T2. Diodes D1 and D2 are respectively inserted in a forward direction from a node N3 toward a terminal TR3 and in a forward direction from the node N3 toward a terminal TR4. An operation of a first transformer and an operation of a second transformer are respectively assigned to a flyback operation and a forward operation.
-
Citations
6 Claims
-
1. A DC-DC converter comprising:
-
a first transformer provided with a first core having a gap, the first core being wound around with a first core primary winding and a first core secondary winding; a second transformer provided with a second core having a gap narrower than the gap of the first core or no gap, the second core being wound around with a second core primary winding and a second core secondary winding; a first switching element serially connected to the first core primary winding and the second core primary winding, the first switching element being set in conducting/non -conductive state in a predetermined period; a first rectifier element in which a first polarity terminal is connected to a first terminal of the first core secondary winding that generates an electromotive force of first polarity when the first switching element conducts, the first rectifier element being biased in a reverse bias condition; a second rectifier element in which the first polarity terminal is connected to a second terminal of the second core secondary winding that generates an electromotive force of second polarity when the first switching element conducts, the second rectifier element being biased in a forward bias condition; a secondary winding connection point to which a third terminal and a fourth terminal are connected, the third terminal being provided at an opposite side of the first terminal of the first core secondary winding and the fourth terminal being provided at an opposite side of the second terminal of the second core secondary winding; a connection point which connects the secondary polarity terminal of the first rectifier element and the second polarity terminal of the second rectifier element; a common current path in common with a current path which includes the first core secondary winding and the first rectifier element and a current path which includes the second core secondary winding and the second rectifier element, the common current path connecting the secondary winding connection point and the connection point;
an output terminal provided on the common current path; andan output coil provided on the common current path. - View Dependent Claims (2, 3, 4, 5)
-
-
6. A transformer comprising:
-
an E-shaped core which is provided with a first external magnetic lead, a central magnetic lead, a second external magnetic lead disposed in parallel on a flat bottom plate, the E-shaped core being arranged in such a manner that a height of the first external magnetic lead is set lower than heights of the central magnetic lead and the second external magnetic lead; a first core, around which a first magnetic flux loop circulates through the central magnetic lead and the first external magnetic lead; a second core around which a second magnetic flux loop circulates through the central magnetic lead and the second external magnetic lead; a first winding which is wound on the central magnetic lead; a second winding which is wound on the first core, and together with the first winding, forms a first transformer having the first core as a magnetic core; and a third winding which is wound on the second core, and together with the first winding, forms a second transformer having the second core as a magnetic core, wherein the transformer comprises either one of an EE-type and an EI-type core.
-
Specification