Did You Know...
...that several people are credited with the invention of the flush toilet? Most people have heard of Thomas Crapper (1837-1910), the sanitary engineer who invented the valve-and-siphon arrangement that made the modern toilet possible. Another claimant to "the throne" was British inventor Alexander Cumming who patented a toilet in 1775. Then there's a nameless Minoan (a native of ancient Crete) who lived 4,000 years ago who supposedly was ahead of his time and created the first flush toilet!
PatentStorm News
Make the Most of Our Site
See this month's Top Inventors and Most Cited Patents.
Stay on top of the latest innovations by subscribing to an RSS feed.
Registered users: Manage your profile.
| Number | Title | Issue Date |
| 7321835 | Method for improving the mode of operation of a matrix converter A method for operating a matrix converter in which m phases of a generator generating alternating voltage with n (n | 01/22/2008 |
| 7282680 | Apparatus for controlling inverter circuit of induction heat cooker An apparatus for controlling an inverter circuit of an induction heat cooker which generates and outputs high voltage power to cook food contained in a cooking container is disclosed. The apparatus varies a pulse width of high level interval of a driving pulse accor... | 10/16/2007 |
| 7259491 | Rotating asynchronous converter A rotating asynchronous converter and a generator device having a first stator connected to a first AC network with a first frequency f1, and a second stator connected to a second AC network with a second frequency f2. The converter has a rotor... | 08/21/2007 |
| 7227330 | Overvoltage suppression technique for variable frequency drives operating reciprocating loads A motor control for a reciprocating load includes overvoltage suppression. The motor control comprises a variable frequency drive (VFD) operatively connected to a power source for operating a motor to drive the reciprocating load. A sensor determines motor torque. A... | 06/05/2007 |
| 7126297 | Controlling method of a motor state A controlling method of a motor state described herein detects the motor operation in a regeneration state or a motor state. The output frequency value of an AC motor drive is calculated and adjusted to stabilize the voltage of a DC bus such that over-voltage protec... | 10/24/2006 |
| 7116067 | Power converter controlling apparatus and method providing ride through capability during power interruption in a motor drive system A method of controlling a power converter (20) of a motor drive system (10)controls the power converter (20) during a first operating mode by applying a current control scheme, which sets power converter commands to control torque current flowin... | 10/03/2006 |
| 7088027 | Rotating asynchronous converter and a generator device The present invention relates to a rotating asynchronous converter and a generator device. The converter comprises a first stator connected to a first AC network with a first frequency f1, and a second stator connected to a second AC network with a second... | 08/08/2006 |
| 7081734 | Ride-through method and system for HVACandR chillers A method of providing ride-through capability in a chiller/refrigeration system employs a variable speed drive with an active converter stage, a DC link stage and an inverter stage for providing variable frequency and voltage to power at least one motor. An inductio... | 07/25/2006 |
| 7054157 | Frequency converter Measures are provided to prevent temperature rise caused by that heat generated from power elements, which is radiated inside a housing. In a housing comprising a radiating section and a cooling fan, a guide is provided on a part of the housing to be made lon... | 05/30/2006 |
| 6906447 | Rotating asynchronous converter and a generator device A rotating asynchronous converter for connection of AC network with equal or different frequencies employs a first stator connected to a first AC network with a first frequency and a second stator connected to a second AC network with a second frequency, and a rotor... | 06/14/2005 |
| 5953225 | Power flow control and power recovery with rotary transformers An interconnection system (100) for transferring power between a first grid (22) operating at a first electrical frequency and a second grid (24) operating at a second electrical frequency includes a rotary transformer (102) and a power recovery system (1... | 09/14/1999 |
| 5757728 | Acoustic transmitter Acoustic transmitter in particular for use in offshore seismic explorations, having sound-emitting surfaces (1, 2) being adapted to be subjected to vibrational movement by means of a drive unit (21) through at least one push element (22A, 22B) and two pla... | 05/26/1998 |
| 4914373 | Generator set for use on a building site The generator set comprises an internal combustion engine (5) driving a three-phase generator (6). The latter is surmounted by a casing (7) containing a converter (8) which is supplied with power by the generator (6) and provides a current of 42 V at 200 ... | 04/03/1990 |
| 4390941 | Static magnetic frequency multiplies A static magnetic frequency multiplier has iron structures which form a closed magnetic circuit and which carry a polyphase primary winding having p1 pole pairs distributed in slots. The winding legs, pitch, interleaving of circuits, setting of... | 06/28/1983 |
| 4387419 | Stationary magnetic frequency multiplier In stationary magnetic frequency multipliers which comprise a polyphase primary winding distributed in slots and a secondary winding magnetically coupled to the former, a travelling field can be produced if the primary and secondary windings, designed as ... | 06/07/1983 |
| 4378587 | Frequency converter apparatus Disclosed is a frequency converter system for altering the frequency of a-c power supplied from a distribution network to a load, the system including a pair of mechanically coupled rotating alternating current machines, the alteration of the rate and dir... | 03/29/1983 |
| 4168459 | Non-interruptible power supply systems A non-interruptible power system (NIPS) for generating polyphase A.C. of a substantially constant desired frequency and a substantially constant selected voltage, comprising: (A) a source of interruptible power and a motor energized thereby, (B) a novel genera... | 09/18/1979 |
| 4079307 | Alternating current generating device An inductor-type high frequency generator with alternating current field excitation and frequency changing output means. An excitation winding provides current for the field winding by way of a rectifier, and automatic voltage regulator and an inverter. I... | 03/14/1978 |
| 4035711 | Rotary frequency-changer A frequency-changer comprising an air-cooled rotary frequency converter having a shaft which carries a rotor of a fan arranged to cool the converter by forced ventilation. The converter is located in a sound-proofed housing through which forced air flow p... | 07/12/1977 |
| 4035712 | Electrical generating apparatus A constant frequency a.c. generating system includes an alternator driven at a variable speed. A rectifier provides a d.c. supply for a rotary inverter. To maintain the voltage and frequency of the inverter output constant, the frequency is monitored and ... | 07/12/1977 |
