Did You Know...
...that when IBM conducted a market study of Chester Carlson's invention in 1959, the company concluded that it would take only 5000 units of his new product to saturate the market? IBM therefore declined to be part of the new product introduction. Too bad for IBM. Carlson's invention was the xerography process, and his new product was the beginning of the Xerox Corporation. It is estimated that every day, worldwide, 3,000,000,000 copies are made!!
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| Number | Title | Issue Date |
| 7312099 | Organic electroluminescent device and fabricating method thereof An organic electroluminescent device includes a substrate, a plurality of gate lines on the substrate, a plurality of data lines on the substrate, each of the plurality of data lines crossing the gate lines, a plurality of switching elements and driving elements int... | 12/25/2007 |
| RE38547 | Frequency-modulated converter with a series-parallel resonance A frequency-modulated converter with a series-parallel resonance, particularly for driving any ohmic or inductive load, including gas discharge tubes, wherein a commutating voltage switch in the form of a transistor is provided and is connected in series between a n... | 07/06/2004 |
| 6472827 | Parallel-resonant inverter-type fluorescent lamp ballast A push-pull inverter is supplied from an inductively current-limited DC voltage source by way of a center-tap on a transformer having significant inductance. This transformer inductance is parallel-coupled with a capacitance means. The inverter is made to... | 10/29/2002 |
| 5627434 | Apparatus for operating a fluorescent lamp of an image forming apparatus An apparatus for operating a fluorescent lamp having first and second power source circuits, the second power source circuit including a high frequency transformer having two or more outputs for supplying pre-heating electric currents to filaments, the se... | 05/06/1997 |
| 5561349 | Frequency-modulated converter with a series-parallel resonance A frequency-modulated converter with a series-parallel resonance, particularly for driving any ohmic or inductive load, including gas discharge tubes, wherein a commutating voltage switch in the form of a transistor is provided and is connected in series ... | 10/01/1996 |
| 4920299 | Push-pull fluorescent dimming circuit A diming circuit for a hot cathode fluorescent lamp is operated in a push-pull mode whereby the hot filaments are alternately the cathode and the anode. Both filaments thus experience similar degradation with time at all brightness levels, thereby enhanci... | 04/24/1990 |
| 4689524 | Fluorescent lamp ballast An electronic fluorescent lamp ballast having at least an energy storing component, a controlling component which has two states, and two socket elements which enables the filaments of the fluorescent lamp to be connected in series with the energy storing... | 08/25/1987 |
| 4684850 | Variable frequency bridge inverter for driving gas discharge lamps A solid state bridge inverter is disclosed wherein the power for driving the transistors is generated by the current flowing to the load. Windings are so connected on the drive transformers that one transistor cannot possibly turn on until the other one i... | 08/04/1987 |
| 4532456 | Output circuit for an electronic ballast system The above and other objects, advantages and capabilities are achieved in one aspect of the invention by an output circuit for an electronic ballast system. The circuit includes N sets of output connections for accepting N lamps. The lamps are driven by an... | 07/30/1985 |
| 4525649 | Drive scheme for a plurality of flourescent lamps The above and other objects, advantages and capabilities are achieved in one aspect of this invention by a drive scheme for a plurality, that is, for N, where N-2, flourescent lamps. The drive circuit comprises (N+1) pairs of output terminals, each compri... | 06/25/1985 |
| 4524305 | Solid state regulated power supply system for cold cathode luminescent tube A solid state power supply and light emission controller for a cold cathode luminescent tube which converts alternating current line voltage, or direct current voltage, into a variable repetition rate pulse alternating current voltage for energizing the t... | 06/18/1985 |
| 4424468 | Inverter ballast circuit with shoot through prevention, auto transformer coupling and overload prevention An inverter ballast for fluorescent lamps utilizing a resonant circuit coupled to the lamp and operated from a source of DC power through transistors. The transistors are controlled by a sensing means in the resonant loop which insures that the transistor... | 01/03/1984 |
| 4414491 | Current limiting power supply for electron discharge lamps A power supply including a high frequency inverter circuit coupled to an electron discharge lamp load through a special purpose transformer is disclosed. The transformer is wound on a saturable ferromagnetic core structure forming a first magnetic flux pa... | 11/08/1983 |
| 4395659 | Power supply device An output transformer for an inverter driven by a pulsating voltage obtained through the full wave rectification of a low frequency alternating current voltage is provided with an auxiliary winding, and a high frequency voltage obtained from the auxiliary... | 07/26/1983 |
| 4161674 | Overvoltage protected fluorescent tube supply circuit To prevent excessive voltages from interfering with a switching transistor supplying a fluorescent tube circuit with alternating pulses from a d-c supply upon removal of the fluorescent tube from the tube transformer, a voltage detector is connected to th... | 07/17/1979 |
| 4061899 | Arrangement for stabilization and ignition of welding arcs by ignition pulses Welding arc stabilizing and igniting is effected with at least one pulse-forming condenser switched by spark gap or semiconductor switch to deliver a sharp discharge pulse through the winding of a pulse transformer, the magnetic energy thus built up in th... | 12/06/1977 |
