Patents by Inventor Franz Ritz
Franz Ritz 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).
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Patent number: 9431936Abstract: A method for diagnosing a frequency converter is used for a frequency converter having a positive and negative DC link voltage which is applied via bridges of switching elements in an alternating sequence to phases of a motor. Pulse width modulation (PWM) signals drive the switching elements for a respective one of the phases and current sensors capture phase currents. In a step a), PWM signals are applied as test patterns to the switching elements. In a step b), sensor signals of the current current sensors are picked up. In a step c), the sensor signals are evaluated by ascertaining a presence of the DC link voltage upon a displacement current being recognized in the sensor signals.Type: GrantFiled: January 14, 2015Date of Patent: August 30, 2016Assignee: DR. JOHANNES HEIDENHAIN GMBHInventors: Franz Ritz, Norbert Huber
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Publication number: 20150214873Abstract: A method for diagnosing a frequency converter is used for a frequency converter having a positive and negative DC link voltage which is applied via bridges of switching elements in an alternating sequence to phases of a motor. Pulse width modulation (PWM) signals drive the switching elements for a respective one of the phases and current sensors capture phase currents. In a step a), PWM signals are applied as test patterns to the switching elements. In a step b), sensor signals of the current current sensors are picked up. In a step c), the sensor signals are evaluated by ascertaining a presence of the DC link voltage upon a displacement current being recognized in the sensor signals.Type: ApplicationFiled: January 14, 2015Publication date: July 30, 2015Inventors: Franz Ritz, Norbert Huber
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Publication number: 20070153890Abstract: A method is for the pulse width modified control of switching elements in a frequency converter having N phases, in which for each phase the control pulses of the switching elements are derived from, in each case, one P-periodic control voltage. The P-periodic control voltages correspond to a superposition of sinusoidal control voltages of period P, that are shifted by 360/N degrees with respect to one another, by an N*P-periodic offset voltage that applies to all phases. The offset voltage is selected such that, at any time, exactly one of the P-periodic control voltages lies effectively on a modulating limit for the derivation of the switching pulses. Using this method, the excitation of resonances at the star point of a connected load may be clearly reduced.Type: ApplicationFiled: December 4, 2006Publication date: July 5, 2007Inventors: Norbert Huber, Franz Ritz, Hans Lengenfelder
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Patent number: 7215041Abstract: A charging circuit for a frequency converter having a first feed line with a first constant current source therein and a second feed line with a second constant current source therein. An intermediate circuit capacitor connected between the first feed line and the second feed line, wherein the first constant current source that limits a charging current of the intermediate circuit capacitor. An electronic control device that controls both the first constant current source and the second constant current source in parallel.Type: GrantFiled: September 5, 2003Date of Patent: May 8, 2007Assignee: Dr. Johannes Heidenhain GmbHInventors: Norbert Huber, Franz Ritz
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Patent number: 6747458Abstract: A method for ground potential monitoring of a rectifier drive, having a capacitor which is connected with a voltage source via a switching device. The method including applying a test voltage between a connector of a capacitor of a rectifier drive and a mass or ground potential prior to connecting the rectifier drive with a voltage source that is connected with the capacitor via a switching device. The method also includes releasing the switching device if a potential of the connector changes by a predetermined amount after the applying the test voltage.Type: GrantFiled: September 27, 2002Date of Patent: June 8, 2004Assignee: Johannes Heidenhain GmbHInventors: Norbert Huber, Franz Ritz
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Publication number: 20040105199Abstract: A charging circuit for a frequency converter having a first feed line with a first constant current source therein and a second feed line with a second constant current source therein. An intermediate circuit capacitor connected between the first feed line and the second feed line, wherein the first constant current source that limits a charging current of the intermediate circuit capacitor. An electronic control device that controls both the first constant current source and the second constant current source in parallel.Type: ApplicationFiled: September 5, 2003Publication date: June 3, 2004Inventors: Norbert Huber, Franz Ritz
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Publication number: 20030067303Abstract: A method for ground potential monitoring of a rectifier drive, having a capacitor which is connected with a voltage source via a switching device. The method including applying a test voltage between a connector of a capacitor of a rectifier drive and a mass or ground potential prior to connecting the rectifier drive with a voltage source that is connected with the capacitor via a switching device. The method also includes releasing the switching device if a potential of the connector changes by a predetermined amount after the applying the test voltage.Type: ApplicationFiled: September 27, 2002Publication date: April 10, 2003Inventors: Norbert Huber, Franz Ritz
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Patent number: 6487785Abstract: A circuit for adjusting a switching threshold of a touch probe, which has a touch element that can be deflected out of a position of repose and which upon a deflection of the touch element out of its position of repose causes a defined change in a measurable system parameter and outputs a switching signal when the value of the system parameter exceeds the switching threshold. The circuit includes a device for measuring the measurable system parameter, an electrical circuit for ascertaining a reference value from which the switching threshold is determinable and an incremental corrector that changes the value of the measurable reference value to the value of the measurable system parameter at the position of repose of the touch element, in which the switching threshold is determinable from the reference value.Type: GrantFiled: June 15, 2000Date of Patent: December 3, 2002Assignee: Dr. Johammes Heidenvain GmbHInventor: Franz Ritz
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Patent number: 6219259Abstract: A circuit arrangement allows a converter to be operated with supply voltages oscillating within broad limits. The intermediate circuit voltage of the converter is controlled to avoid unacceptably high currents, so that the intermediate circuit voltage is always higher than the peak value of the rectified supply voltage. For at least this purpose, the peak value of the rectified supply voltage is determined and compared to that of the intermediate circuit voltage. If the intermediate circuit voltage is less than the peak value of the rectified supply voltage, the intermediate circuit voltage is increased to exceed the originally set setpoint value. This prevents free-wheeling diodes from becoming conductive at undesirable times and causing excessive currents.Type: GrantFiled: December 8, 1999Date of Patent: April 17, 2001Assignee: Dr. Johannes Heidenhain GmbHInventors: Norbert Huber, Franz Ritz
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Patent number: 5109223Abstract: An apparatus is provided for inductive transfer of the scanning signal from a sensing head to a machine body. The apparatus includes cooperating inductive coupling elements between a receiving lug of the sensing head and the spindle of the machine. Cooperating coupling elements for inductive coupling are also provided between the spindle and the machine body. The coupling element of the receiving lug includes a coil with a ferromagnetic core. The spindle includes a second cooperating coil lying opposite to the receiving-lug coil which also includes a ferromagnetic core. The scanning signal is conducted from the detector to the coil in the receiving lug and is transferred inductively to the spindle. The scanning signal then passes over a transfer coil to a receiving coil. The transfer coil and receiving coil are configured such that the signal is transferred independently of rotation of the spindle relative to the machine body.Type: GrantFiled: April 26, 1989Date of Patent: April 28, 1992Assignee: Dr. Johannes Heidenhain GmbHInventors: Walter Schmitt, Franz Ritz
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Patent number: 4594579Abstract: An incremental length measuring instrument generates analog scanning signals S.sub.1, S.sub.2 with a certain period P which are applied to a comparator in conjunction with two reference signals R.sub.S1, R.sub.S2. The measuring instrument causes the scanning signals S.sub.1, S.sub.2 to change as a function of relative displacement to two components of the measuring instrument. The comparator generates an analog control signal S.sub.D as a function of the difference of the momentary values of the signals applied as inputs to the comparator. The analog control signal S.sub.D is applied as an input to a signal generator which includes an oscillator. The oscillator generates a number of pulses in dependence on the momentary value of the analog control signal S.sub.D. These pulses cause the reference signals R.sub.S1, R.sub.S2 to be modified by the signal generator. In addition, the pulses are fed in a direction dependent manner into an incremental counter which includes a numerical display.Type: GrantFiled: January 20, 1983Date of Patent: June 10, 1986Assignee: Dr. Johannes Heidenhain GmbHInventors: Walter Schmitt, Franz Ritz