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...that after Parker Brothers executives turned down the game of Monopoly because it had "52 fundamental errors" (including taking too long to play), a copy of the game wound up in the home of the company president who stayed up until 1 a.m. to finish playing it? He was so impressed by the game that the next day he wrote to inventor Charles Darrow and offered to buy it!
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US Patent 6806686 - Charge balancing circuit
US Patent Issued on October 19, 2004
Estimated Patent Expiration Date:
April 25, 2023Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
Estimated Patent Expiration Date:
April 25, 2023Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.AbstractA charge balancing circuit is disclosed that is configured to provide charge balancing for a bank of series connected charge storage devices such as capacitors. One embodiment of the charge balancing circuit comprises a voltage divider, an operational amplifier, and a negative feedback resistor connected between every two capacitors. The circuit is configured to monitor the voltage in each of the capacitors and, if the voltage in one of the capacitors is higher than the other, the circuit transfers energy from the higher charged capacitor to the lower charged capacitor until the capacitors are balanced. A current limiting resistor can be included for limiting the output current of the operational amplifier to a safe value and for providing feedback information regarding the health of the capacitor. An additional gain stage can also be included for increasing the output current of the operational amplifier for banks of large charge storage devices such as capacitors. | InventorAssigneeApplicationNo. 10423708 filed on 04/25/2003US Classes:320/118With discharge of cells or batteriesField of Search320/116, SERIALLY CONNECTED BATTERIES OR CELLS320/118, With discharge of cells or batteries320/119, With individual charging of plural batteries or cells320/121, Switchable cells (e.g., for voltage regulation, etc.)320/127, BATTERY OR CELL DISCHARGING320/128With chargingExaminersPrimary: Tso, Edward H.Attorney, Agent or FirmUS Patent References3237078, 4053824, Method and device for checking a storage batteryIssued on: 10/11/1977 Inventor: Dupuis, et al.4238721, System and method for charging electrochemical cells in series Issued on: 12/09/1980 Inventor: DeLuca , et al.4242627, Battery charger Issued on: 12/30/1980 Inventor: Kisiel4303877, Circuit for protecting storage cells Issued on: 12/01/1981 Inventor: Meinhold4449091, Power controlling circuit for automatic regulating apparatus Issued on: 05/15/1984 Inventor: Otoi4814692, Circuit and method for measuring and digitizing the value of a resistance Issued on: 03/21/1989 Inventor: Baumann4821724, Pacing pulse compensation Issued on: 04/18/1989 Inventor: Whigham , et al.4903700, Pacing pulse compensation Issued on: 02/27/1990 Inventor: Whigham, et al.5479083, Non-dissipative battery charger equalizer Issued on: 12/26/1995 Inventor: Brainard5504415, Method and apparatus for automatic equalization of series-connected batteries Issued on: 04/02/1996 Inventor: Podrazhansky, et al.5524488, Flux control groove Issued on: 06/11/1996 Inventor: Foote5532665, Low stress magnet interface Issued on: 07/02/1996 Inventor: Foote, et al.5578914, Charging system for multi-cell battery Issued on: 11/26/1996 Inventor: Morita5587530, Low stress magnet interface for a force rebalance accelerometer Issued on: 12/24/1996 Inventor: Foote, et al.5710504, Switched capacitor system for automatic battery equalization Issued on: 01/20/1998 Inventor: Pascual, et al.5747968, Lithium polymer battery charger apparatus Issued on: 05/05/1998 Inventor: Merritt, et al.5773959, Lithium polymer battery charger methods and apparatus Issued on: 06/30/1998 Inventor: Merritt, et al.5821733, Multiple cell and serially connected rechargeable batteries and charging system Issued on: 10/13/1998 Inventor: Turnbull5886502, Cell balance circuit having rechargeable cells Issued on: 03/23/1999 Inventor: Higashijima5905360, Battery system and electric motor vehicle using the battery system with charge equalizing features Issued on: 05/18/1999 Inventor: Ukita5932932, Storage battery voltage control apparatus Issued on: 08/03/1999 Inventor: Agatsuma, et al.5943224, Post regulator with energy recovery snubber and power supply employing the same Issued on: 08/24/1999 Inventor: Mao5956241, Battery cell equalization circuit Issued on: 09/21/1999 Inventor: LoCascio5982050, Power supply unit for automotive vehicle Issued on: 11/09/1999 Inventor: Matsui5982144, Rechargeable battery power supply overcharge protection circuit Issued on: 11/09/1999 Inventor: Johnson, et al.6008623, Charge equalizer or series of connected battery strings Issued on: 12/28/1999 Inventor: Chen, et al.6043628, Management process for electrical energy storage battery systemsand control arrangement for application of the process Issued on: 03/28/2000 Inventor: Perelle, et al.6046573, System for equalizing the level of charge in batteries Issued on: 04/04/2000 Inventor: Wikstrom6064178, Battery charge balancing system having parallel switched energy storage elements Issued on: 05/16/2000 Inventor: Miller6104164, Cell voltage detecting device for combination battery Issued on: 08/15/2000 Inventor: Iino, et al.6114835, Multi-cell battery pack charge balancing circuit Issued on: 09/05/2000 Inventor: Price6121751, Battery charger for charging a stack of multiple lithium ion battery cells Issued on: 09/19/2000 Inventor: Merritt6140800, Autonomous battery equalization circuit Issued on: 10/31/2000 Inventor: Peterson6452363Multiple battery charge equalizer Issued on: 09/17/2002 Inventor: Jabaji International ClassH02J 700 |
