Patents by Inventor Bo Ekdahl

Bo Ekdahl 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).

  • Buzzer with Zener diode in discharge path
    Patent number: 6111497
    Abstract: A relatively high voltage is developed across a buzzer by placing a resistance in the discharge path of an buzzer, e.g., by shunting one or more Zener diodes or LEDs across a switching transistor, the switching transistor being connected in series with the buzzer between a voltage potential and ground. Alternatively, the buzzer is shunted with a resistive element, with or without series connected a reversed biased diode. The result is a higher audio output without a corresponding increase in power consumption.
    Type: Grant
    Filed: March 12, 1999
    Date of Patent: August 29, 2000
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventors: Hakan Andersson, Bo Ekdahl