Patents by Inventor Tjerk Bij De Leij

Tjerk Bij De Leij 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).

  • Timer with adjustable time control based on an RC oscillator with a variable resistor, and toaster including such a timer
    Patent number: 5938960
    Abstract: An RC oscillator having an oscillation frequency which is controllable by supplying a step voltage signal to a series arrangement of a capacitor and a resistor, the oscillation frequency being dependent on the time for the capacitor to be charged to a given voltage level. In order to vary the frequency, the amplitude of the supplied step voltage is varied instead of the resistance of the resistor via which the capacitor is charged. The amplitude variation can be provided, for example, by a potentiometer which acts as a voltage divider for the step voltage. The tolerance of the potentiometer in regard to its resistance value will not be relevant, because it is only the ratio between different portions thereof which is determinative. The step voltage, and consequently the oscillation frequency, will be proportional to the setting of the potentiometer regardless of the resistance tolerance thereof.
    Type: Grant
    Filed: July 14, 1998
    Date of Patent: August 17, 1999
    Assignee: U.S. Philips Corporation
    Inventors: Klaas J. Lulofs, Tjerk Bij De Leij