Patents by Inventor Matti Havukainen

Matti Havukainen has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6356468
    Abstract: The invention disclosed here relates to a method and arrangement for limiting the starting current in a switching power supply. As the operating voltage is switched on in the power supply an uncharged capacitor (C1) in the power supply represents a short circuit, generating a large starting current which is limited by a limiting element (16) to a desired value. To ensure uninterrupted operation of the switching power supply the limiting element (16) should be bypassed as soon as possible after the switching-on of the operating voltage. Therefore, in parallel with the limiting element (16) there is provided a bypass unit (14) via which the bypass current can be conducted. The limiting element bypass unit (14) is controlled by a control signal which is generated by means of a capacitive voltage divider circuit from the primary voltage.
    Type: Grant
    Filed: May 17, 2001
    Date of Patent: March 12, 2002
    Assignee: Nokia Networks Oy
    Inventors: Matti Havukainen, Juha Riihimaki