Patents Represented by Attorney, Agent or Law Firm Havey D. Fried
  • Patent number: 6549386
    Abstract: The protection circuit for a switch has an energy-storage means, which is connected to a control input of the switch and which is charged with a delay via resistance means when a control voltage is present and is discharged via switching means when the control voltage is low or absent, and has a switching stage which is connected to a supply voltage, is switched on when a specific threshold voltage is present across the energy-storage means and in this way reduces the supply voltage. In one exemplary embodiment, when the switching stage is switched on, the charge which is dissipated from the supply voltage is at least partially routed to the energy-storage means via a diode which is connected in parallel with the said energy-storage means, so that the phase during which the switching stage is switched on is lengthened and the energy-storage means, in this case a capacitor, is completely discharged.
    Type: Grant
    Filed: April 17, 2000
    Date of Patent: April 15, 2003
    Assignee: Thomson Licensing SA
    Inventors: Reinhard Koegel, Eugen Kizmann, Jean-Paul Louvel