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1. (WO1998018198) ACTIVE RECTIFIER CIRCUIT

Pub. No.:    WO/1998/018198    International Application No.:    PCT/FI1997/000632
Publication Date: Apr 30, 1998 International Filing Date: Oct 17, 1997
IPC: H02M 3/335
Applicants: A. AHLSTROM CORPORATION
SAIRANEN, Martti
SALONEN, Olli
Inventors: SAIRANEN, Martti
SALONEN, Olli
Title: ACTIVE RECTIFIER CIRCUIT
Abstract:
The invention relates to power sources, more particularly to rectifier circuits realised with MOSFET-transistors. In the system according to the invention, the sources of MOSFET switching transistors are connected to ground potential, and the secondary windings of the main transformer are connected in between the switching transistor drain and the positive outlet of the power source. The grid control of the MOSFET-transistors is arranged with small power transformers from between the switching transistor drain and the secondary winding of the main transformer, and according to the secondary voltage of said power transformers, the separate grid control circuits switch the MOSFET-transistors rapidly to conductive or non-conductive mode. By employing the arrangement according to the invention, there is achieved an extremely rapid switching and respectively extremely low power losses.