Did You Know...
...Chester Carlson was a patent agent who tired of having to make multiple copies of patent applications using the only duplication method available at the time: carbon paper. In 1959 he came up with a new copying system and took it to IBM for evaluation. The "experts" at IBM determined potential sales to be only 5,000 units because people wouldn't want to use a bulky machine when they had carbon paper. Carlson's invention was the xerography process, the company founded on the system is Xerox.
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| Number | Title | Issue Date |
| 5479335 | Regulated DC voltage power supply A regulated DC voltage power supply including a plurality of power circuits connected in parallel, and a control circuit. Each of the power circuits includes a switching device that chops the input DC voltage, and the control circuit includes a detecting ... | 12/26/1995 |
| 5460244 | Elevator control apparatus using parallel converters and inverters with means to control circulating current The present invention provides an elevator speed control system in one mode, including: a plurality of converters connected in parallel for converting an AC voltage to a DC voltage by means of controllable devices; a capacitor for smoothing output voltage... | 10/24/1995 |
| 5406470 | AC/DC converter An AC/DC converter is provided for connecting to conductors of a multi-phased alternating current generator or network, which is built redundantly for protection against a total loss and which loads the AC generator essentially without non-linear distorti... | 04/11/1995 |
| 5398182 | Power supply A power supply wherein the rectified output of two or more transformer secondaries are connected in series and then parallel each half cycle of an alternating current energization signal. Logic circuitry monitors the rectified output and automatically swi... | 03/14/1995 |
| 5267137 | High-power power supply The invention concerns a high power power supply with output power in excess of 5 kilowatts, by way of example, for the supply of electromagnets in the area of electromedicine and nuclear physics. In order to regulate the output current, power thyristors ... | 11/30/1993 |
| 5103388 | Low harmonic current and fault tolerant power supply A fault tolerant power supply comprises a first rectifier and a second rectifier with a boost circuit for correcting line current harmonics. The second rectifier, the boost circuit and output diodes are connected in parallel with the first rectifier. A ca... | 04/07/1992 |
| 5088019 | Low harmonic current and fault tolerant power supply A fault tolerant power supply comprises a first rectifier and a second rectifier with a boost circuit for correcting line current harmonics. The second rectifier, the boost circuit and output diodes are connected in parallel with the first rectifier. A ca... | 02/11/1992 |
| 4787022 | High voltage power source for a discharge tube A high voltage power source for supplying a DC high voltage to a discharge tube, can detect an abnormality when created at the discharge tube side and stop its output. The high voltage power source is provided with a detector circuit which detects when th... | 11/22/1988 |
| 4713741 | Excitation control apparatus for rotary electric machine An excitation control apparatus for a rotary electric machine according to this invention is such that principal portions of an automatic voltage regulator are dualized by effectively combining circuits preferring decrease of a field current and circuits ... | 12/15/1987 |
| 4672526 | Rectifying circuit arrangement for generating at least one controllable direct voltage from at least one alternating voltage In order to produce direct voltages with greater flexibility, a rectifier (1) according to the invention comprises an alternating voltage measuring sensor (25), a comparator (22), controllable switches (160 to 183) and a switch control (20), through which... | 06/09/1987 |
| 4672226 | Redundant resistance temperature detector power supply system A redundant power supply/signal conditioner system for a resistance temperature detector includes power supply/signal conditioner modules having first and second output terminals connected to a resistance temperature detector. Diode circuits are connected... | 06/09/1987 |
| 4663702 | Power converter apparatus and control method thereof A power converter apparatus has at least two converters CONV1 and CONV2. The DC side of each of the converters CONV1 and CONV2 is connected to a filtering capacitor Cd which serves as a DC power source for a load device LOAD. The AC side of the converter ... | 05/05/1987 |
| 4660138 | Multiple output multiple step-up rectifier circuit In a multiple output multiple step-up rectifier circuit of the invention, an output voltage of a power source circuit is supplied to a plurality of Crockroft-Walton multiple step-up rectifier circuits connected in parallel with each other. The capacitor c... | 04/21/1987 |
| 4633412 | Option protocol arrangement for stored program rectifier controller A rectifier plant control system includes a stored program of a master control to control operation and monitor rectifier plant conditions. The master control is designed to cooperate with optional control systems to accomplish new operations without requ... | 12/30/1986 |
| 4598352 | Controlled parallel converter plant The electrical converter or inverter plant comprises several converter modules arranged in parallel between a power supplying line and a power consuming line. Each converter module includes a power converting unit being controlled by a control circuit whi... | 07/01/1986 |
| 4471855 | Control device for an A.C. elevator This invention is designed to prevent the large charging current from flowing to the capacitor at the start of the elevator for preventing damage of the elements of the rectifier device. Thus the present device provides a control device for an a.c. elevat... | 09/18/1984 |
| 4456870 | Split windings motor vehicle alternator The alternator comprises an induction winding sub-divided into two half-windings (1, 2) each connected to the input terminals of a respective double half-wave rectifier circuit (3, 4). It further includes thyristors (14) each of which connects a terminal ... | 06/26/1984 |
| 4451773 | Rectifier control system for a DC power plant system A DC power plant system has the operation of its individual rectifiers controlled by a stored program control system for the purpose of optimizing power efficiency. Load power requirements are compared with rated capacities of operating rectifiers of the ... | 05/29/1984 |
| 4441032 | Converter control apparatus for parallel connected multi-terminal direct current system Two rectifiers and two inverters are operated under the state under which they are connected in parallel by common transmission lines. These rectifiers and inverters are controlled an independent control apparatus respectively which can selectively apply ... | 04/03/1984 |
| 4366532 | AC/DC or DC/AC Converter system with improved AC-line harmonic reduction In a transformer-rectifier converter system, at least one inductance is inserted in the commutation path of two adjacent diode or thyristor devices in a cluster of three devices related to a common DC polarity pole, the reactance due to such inductance be... | 12/28/1982 |
| 4339704 | Series parallel transition for power supply A multi-winding a-c electric power supply is connected to a d-c load circuit via a power rectifier assembly comprising at least two legs connected in parallel across the load circuit. Each leg has at least four serially interconnected unilaterally conduct... | 07/13/1982 |
| 4228477 | Circuit for monitoring the current distribution in parallel-connected converted branches A circuit arrangement for monitoring the current inbalance in two parallel-connected converter branches, each of which includes at least two series-connected converter valves. The anodes and cathodes, respectively, of adjacent converter valves in a given ... | 10/14/1980 |
| 4218646 | AC Feeding apparatus and rotating field apparatus having AC feeding apparatus An AC feeding apparatus which comprises a plurality of series solid state switch groups connected in parallel and with each series solid state switch group comprising N solid state switches connected in series. AC windings are provided for n(nࣙ1) phase ... | 08/19/1980 |
| 4208709 | Rectifiers A rectifier unit for 3-phase a.c. to d.c. conversion is of the type having a transformer with a star-connected and a delta-connected secondary the outputs of which are rectified and combined to give 12-pulse operation. To reduce the danger of current imba... | 06/17/1980 |
| 4056768 | Static convertor plant In a convertor plant for connection between a DC network and an AC network which includes at least one convertor group formed of two convertors with AC terminals for connection to the AC network and DC terminals for connection to the DC network, a reactor... | 11/01/1977 |
| 4013955 | Analog signal processor An analog signal processor that is particularly suitable for measuring, igrating and holding a single or a pair of analog signals. The input signal to the analog signal processor may be sinusoidal of relatively low frequency and of low signal strength an... | 03/22/1977 |
| 4009431 | Series parallel transition for power supply An AC generator or other AC source has two identical output sections which are connected through corresponding rectifiers to drive a DC load such as a group of DC traction motors connected in parallel for driving a locomotive. The rectifiers are selective... | 02/22/1977 |
| 3938025 | DC to DC converter for producing two individually controlled and stabilized DC-voltages A DC to DC converter which gives two individually controlled and stabilized DC voltages includes an oscillator of the push-pull type and two rectifiers which are connected to the output of the oscillator. The transformer of the oscillator has a primary wi... | 02/10/1976 |
