1
Frederick A Stich, Thomas G Hubert, David L Layden, Donald K Zahrte: Uninterruptible power system. Best Power Technology Incorporated, Foley & Lardner, February 11, 1997: US05602462 (281 worldwide citation)

An uninterruptible power system has a transformer with a primary connected to input terminals, a secondary connected to output terminals, a static switch connected between the input terminals and the primary, and an auxiliary primary connected to an inverter which is supplied by a battery to provide ...


2
Frederick A Stich, Edward G Beistle: Method and apparatus for determination of battery run-time in uninterruptible power system. Best Power Technology Corporation, Foley & Lardner, March 15, 1994: US05295078 (167 worldwide citation)

The run-time on battery power available from an uninterruptible power system is accurately determined both during supply of power from the battery through an inverter to the load and during the time where power is supplied directly from an AC power system to the load. During power outages where powe ...


3
Frederick A Stich, Donald K Zahrte Sr, Richard V Baxter Jr, Douglas C Folts, Thomas G Hubert, Juan M Medina, William J Hazen, Edward G Beistle: Back-up uninterruptible power system. Best Power Technology, Foley & Lardner, May 24, 1994: US05315533 (150 worldwide citation)

A back-up uninterruptible power system has a power supply path from input terminals connected to AC power system lines to normally supply power to a load. Upon the occurrence of a line fault, a static switch in the power supply path interrupts the connection between the AC power lines and the load a ...


4
Frederick A Stich, Peter W Jungwirth, Donald K Zahrte Sr: Standby power system. General Signal Corporation, Foley & Lardner, August 4, 1998: US05790391 (88 worldwide citation)

A standby power system is provided having power conversion, output voltage control, and line-fault detection systems that make possible a significant reduction in the cost of the system. The standby power system provides backup power to a load, such as a computer system, when main AC line power fail ...


5
Frederick A Stich: Transistor bridge inverter motor drive having reduced harmonics. Allis Chalmers Corporation, Lee H Kaiser, June 29, 1976: US03967173 (61 worldwide citation)

A harmonic reduced pulse width modulation, variable speed transistor bridge inverter drive controls frequency and magnitude of stator voltage applied to an induction motor so as to maintain constant flux in the motor and permit maximum driving torque to be realized from the motor over a wide speed r ...


6
Richard V Baxter Jr, Frederick A Stich: Method and apparatus for line power monitoring for uninterruptible power supplies. Best Power Technology, Foley & Lardner, July 20, 1993: US05229651 (48 worldwide citation)

AC line monitoring is provided for uninterruptible power supplies to detect AC power system line faults by comparing the presently received cycle of the AC power line signal with a reference waveform. The reference waveform is formed of a composite of waveforms from prior cycles which adapts over ti ...


7
Frederick A Stich, Conrad F Williams: Solid state circuit protection system and method. Siemens Allis, F W Powers III, December 27, 1983: US04423459 (46 worldwide citation)

A control for an AC circuit protection system which is capable of monitoring either single phase or polyphase current flow. The composite current envelope is periodically sampled and the sample values converted into digital form. Succeeding current signals are tested to determine whether they deviat ...


8
Frederick A Stich: Transistor inverter motor drive having voltage boost at low speeds. Allis Chalmers Corporation, Lee H Kaiser, July 27, 1976: US03971972 (46 worldwide citation)

A transistor inverter drive provides variable frequency and variable voltage power to an electric motor and pulse width modulates a predetermined number of harmonic-reduced constant volt/hertz pulses per cycle of motor frequency to selectively vary the motor stator voltage so that constant torque ov ...


9
Frederick A Stich, Donald K Zahrte Sr, Gregory C Kohls, Robert R Davidson: Dynamic voltage regulation stabilization for AC power supply systems. General Signal Corporation, Foley & Lardner, March 17, 1998: US05729120 (30 worldwide citation)

Instabilities in the output voltage provided from an AC power supply system such as an uninterruptible power supply connected to a power factor correcting load are suppressed by a dynamic voltage regulation stabilizer system which is connected across the output lines from the power supply system to ...


10
Thomas P Gilmore, Frederick A Stich: Adjustable speed electric motor drive having constant harmonic content. Allis Chalmers Corporation, Lee H Kaiser, October 31, 1978: US04123692 (28 worldwide citation)

An adjustable speed AC electric motor drive has a static inverter energized from a unidirectional power source through a semiconductor series chopper and eliminates a filter between chopper and inverter and controls the fundamental inverter output frequency as a function of an analog speed reference ...