Patents by Inventor Lothar Behrend

Lothar Behrend 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: 4619337
    Abstract: In order to reduce the coupling-in of high-frequency electromagnetic interference into the measuring system of electric balances with scale on top and with a metallic balance scale and a metallic housing, a pin (7) which establishes the connection between the balance scale (2) and the load receiver (5) of the measuring system comprises an insulating layer on its surface which is bridged by a resistor (6) located on the pin (7).
    Type: Grant
    Filed: March 26, 1985
    Date of Patent: October 28, 1986
    Assignee: Sartorius GmbH
    Inventors: Lothar Behrend, Jurgen Ober, Erich Knothe, Franz-Josef Melcher
  • Patent number: 4450923
    Abstract: It is known in high-resolution electronic weighing scales based on the principle of electromagnetic force compensation that the load-dependent development of heat in the coil and the precision resistor can be compensated by sending an additional alternating current through the coil and the precision resistor which is complementarily regulated in its amplitude. In order to make possible a precise regulation of the amplitude of the additional alternating current even in the case of a small carrying force of the electromagnetic force compensation and of a correspondingly small direct compensating current, the invention proposes connecting in a voltage divider in parallel to the coil and the precision resistor which has a highly temperature-dependent resistor. In this parallel branch direct and alternating current are higher by a constant proportionality factor than in the main branch formed by coil and precision resistor.
    Type: Grant
    Filed: December 17, 1982
    Date of Patent: May 29, 1984
    Assignee: Sartorius GmbH
    Inventors: Lothar Behrend, Erich Knothe, Franz-Josef Melcher, Jurgen Ober
  • Patent number: 4450924
    Abstract: It is known in high-resolution electronic weighing scales based on the principle of electromagnetic force compensation that the load-dependent development of heat in a coil and a precision resistor can be compensated by sending an additional alternating current through the coil and the precision resistor which is complementarily regulated in its amplitude. In order to regulate the amplitude of this alternating current, the invention proposes a simplified circuit which comprises a highly temperature-dependent resistor, the resistance value of which is set at a fixed theoretical value.
    Type: Grant
    Filed: December 17, 1982
    Date of Patent: May 29, 1984
    Assignee: Sartorius GmbH
    Inventors: Lothar Behrend, Eric Knothe, Franz-Josef Melcher, Jurgen Ober
  • Patent number: 4300647
    Abstract: A scale of the electromagnetic force compensation principle, having a stationary permanent magnet system with an air gap and at least one coil positioned in the air gap, the coil being acted upon via a position sensor and a variable-gain amplifier by a compensation direct current dependent on the load of the scale, wherein the compensation direct current flows through a measuring resistor from both ends of which a signal dependent on the load of the scale is tapped off and fed to an analog/digital converter, and further electric circuits are connected therewith which permit an alternating current to flow, in addition to the compensation direct current, through the coil and the measuring resistor and including a regulating or adjusting device which modifies the amplitude of the additional alternating current in such a manner that the joulean heat generated in the coil and in the measuring resistor by the compensation direct current and by the additional alternating current is at least approximately load-indepe
    Type: Grant
    Filed: July 23, 1980
    Date of Patent: November 17, 1981
    Assignee: Sartorius GmbH
    Inventors: Erich Knothe, Franz-Josef Melcher, Jurgen Ober, Lothar Behrend