Patents by Inventor Nai-Chi Lee
Nai-Chi Lee has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 6844702Abstract: A system, method and apparatus for contact-less charging of battery operated devices, including a host charger with a power converter and resonant tank circuit and a portable device where the battery is located, with a battery charging control IC, wherein the method obviates the need for a voltage controller in each of both the host and the portable stages. The charging of the battery in the portable device is controlled by a charging controller therein, which is in continual electric communication with the host, whose output power the control IC dynamically monitors and controls. In one embodiment, component count is minimized but battery charging is not optimized when the battery voltage is very low. In the other embodiment, charging efficiency is maximized regardless of the output voltage of the battery.Type: GrantFiled: May 16, 2002Date of Patent: January 18, 2005Assignee: Koninklijke Philips Electronics N.V.Inventors: Demetri Giannopoulos, Qiong M Li, Nai-Chi Lee
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Patent number: 6788555Abstract: A bi-directional flyback circuit includes a primary side switch that regulates the re-circulated energy to achieve substantially zero voltage switching (ZVS) and a secondary-side switch that regulates the output voltage. No feedback circuit between an output side and an input side of the bi-directional flyback circuit is needed for regulating the output voltage. The amount of recirculating energy required to achieve ZVS, and to maintain output regulation is kept substantially at a minimum.Type: GrantFiled: September 26, 2002Date of Patent: September 7, 2004Assignee: Koninklijke Philips Electronics N.V.Inventors: Laurence Bourdillon, Demetri Giannopoulos, Nai-Chi Lee
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Publication number: 20040062061Abstract: A bi-directional flyback circuit includes a primary side switch that regulates the re-circulated energy to achieve substantially zero voltage switching and a secondary-side switch that regulates the output voltage. No feedback circuit between an output side and an input side of the bi-directional flyback circuit is needed for regulating the output voltage.Type: ApplicationFiled: September 26, 2002Publication date: April 1, 2004Applicant: Koninklijke Philips Electronics N. V.Inventors: Laurence Bourdillon, Demetri Giannopoulos, Nai-Chi Lee
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Patent number: 6674655Abstract: A power supply comprising a flyback converter and a controller is disclosed. The flyback converter drives a load when electrically coupled to an alternating current power source. The controller controls a soft switching during each switching time period of the flyback converter. Upon an initial switching time period, the controller determines each acceptable switching frequency for the subsequent switching time periods and selects one of the acceptable switching frequencies for soft switching the flyback converter over one or more switching time periods during a constant load.Type: GrantFiled: December 29, 2000Date of Patent: January 6, 2004Assignee: Koninklijke Philips Electronics N.V.Inventors: Demetri Giannopoulos, Nai-Chi Lee, Qiong Li
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Publication number: 20030214821Abstract: A system, method and apparatus for contact-less charging of battery operated devices is presented. There is a host charger with a power converter and resonant tank circuit and a portable device where the battery is located, with a battery charging control IC. The method obviates the need for a voltage controller in each of both the host and the portable stages, thus decreasing complexity and increasing efficiency. The charging of the battery in the portable device is controlled by a charging controller therein, which is in continual electric communication with the host, whose output power the control IC dynamically monitors and controls. Two embodiments for the charging circuitry in the portable device are presented. In one embodiment component count is minimized but battery charging is not optimized when the battery voltage is very low. In the other embodiment charging efficiency is maximized regardless of the output voltage of the battery, but additional components are utilized.Type: ApplicationFiled: May 16, 2002Publication date: November 20, 2003Applicant: Koninklijke Philips Electronics N.V.Inventors: Demetri Giannopoulos, Qiong M. Li, Nai-Chi Lee
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Patent number: 6563718Abstract: A power converter apparatus employing a capacitively coupled feedback network for facilitating bi-directional communication between a primary and secondary side of the converter while maintaining direct current isolation.Type: GrantFiled: December 6, 2001Date of Patent: May 13, 2003Assignee: Koninklijke Philips Electronics N.V.Inventors: Qiong Michelle Li, Nai-Chi Lee
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Patent number: 6549432Abstract: A multiple-output, bi-directional flyback converter with soft switching of an input switch is disclosed. The primary-side of the converter is comprised of an input power supply, a transformer with a primary winding and a secondary winding, and an input switch with an associated diode, wherein a first end of the primary winding is connected to the input power supply and a second end of the primary winding is connected to the input switch. A first predetermined number of output voltage circuits are connected to a single secondary winding or one of a plurality of secondary windings each producing an output voltage. Each output voltage circuit has an output switch with an associated diode, and a diode connected in series between the output voltage switch and the secondary winding. A last output voltage circuit with a bi-directional switch and associated diode is connected connection to the secondary winding.Type: GrantFiled: February 28, 2002Date of Patent: April 15, 2003Assignee: Koninklijke Philips Electronics N.V.Inventors: Demetri Giannopoulos, Laurence Bourdillon, Nai-Chi Lee
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Patent number: 6510066Abstract: A switch mode power supply (SMPS) and method are provided. In particular, the present invention provides an SMPS in which data is encoded by manipulating voltage pulses on a primary side. The manipulated voltage pulses are then transferred over a transformer to a secondary side. Secondary side pulses generated in response to the primary side pulses are sensed and decoded by a detector. The present invention allows data to be transferred from the primary side to the secondary side without affecting output voltages.Type: GrantFiled: March 30, 2001Date of Patent: January 21, 2003Inventors: Demetri Giannopoulos, Qiong Li, Nai-Chi Lee
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Publication number: 20020141210Abstract: A switch mode power supply (SMPS) and method are provided. In particular, the present invention provides an SMPS in which data is encoded by manipulating voltage pulses on a primary side. The manipulated voltage pulses are then transferred over a transformer to a secondary side. Secondary side pulses generated in response to the primary side pulses are sensed and decoded by a detector. The present invention allows data to be transferred from the primary side to the secondary side without affecting output voltages.Type: ApplicationFiled: March 30, 2001Publication date: October 3, 2002Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.Inventors: Demetri Glannopoulos, Qiong Li, Nai-Chi Lee
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Publication number: 20020085394Abstract: A power supply comprising a flyback converter and a controller is disclosed. The flyback converter drives a load when electrically coupled to an alternating current power source. The controller controls a soft switching during each switching time period of the flyback converter. Upon an initial switching time period, the controller determines each acceptable switching frequency for the subsequent switching time periods and selects one of the acceptable switching frequencies for soft switching the flyback converter over one or more switching time periods during a constant load.Type: ApplicationFiled: December 29, 2000Publication date: July 4, 2002Inventors: Demetri Giannopoulos, Nai-Chi Lee, Qiong Li
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Patent number: 6400581Abstract: A method for reducing power losses in a semiconductor switching device in a switching power converter by continuously monitoring an instantaneous power dissipation signal in the switching device and creating an appropriate correction signal to optimize that parasitic power dissipation. A multitude of strobed current and voltage measurement signals associated with the switching device are obtained over a time period using a pair of analog-to-digital converters (ADCs). These measurement signals are used to calculate the multitude of instantaneous power signals, then to derive an average power dissipation signal for a complete cycle and create the correction signal based on a comparison with a reference signal in memory. The correction signal can be, derived in a computer via an algorithm or a look-up table, and would preferably provide a relative adjustment in the timings of the switching device.Type: GrantFiled: April 16, 2001Date of Patent: June 4, 2002Assignee: Koninklijke Philips Electronics N.V.Inventor: Nai-Chi Lee
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Patent number: 6341073Abstract: A method for controlling a switching converter includes receiving a digitized waveform of a continuous switch parameter; analyzing the digitized waveform to detect a parameter local minimum; and opening the switch at a parameter local minimum. An apparatus implements the method preferably using a microcontroller and at least one waveform digitizer to determine instantaneous power dissipation. The microcontroller selects an optimum local minimum of the switching waveform to achieve optimum power dissipation.Type: GrantFiled: November 16, 2000Date of Patent: January 22, 2002Assignee: Philips Electronics North America CorporationInventor: Nai-Chi Lee
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Patent number: 6011387Abstract: To improve testability of analog or mixed analog/digital circuit modules mounted on a carrier, three-way switches are placed at input and output ports of the circuit modules. The switches can operate to establish signal connections between a test bus and core circuits inside the modules. The switches can also establish signal connections between the test bus and glue circuits disposed between the modules.Type: GrantFiled: December 19, 1997Date of Patent: January 4, 2000Assignee: Philips Electronics North America CorporationInventor: Nai-Chi Lee
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Patent number: 5936446Abstract: Pulse width modulation driver circuitry both limits and regulates the voltage that is applied to a load from a power source which provides a voltage that may far exceed the maximum safe load voltage. The driver circuitry includes a reactive filter coupled to the load, a voltage sensor for sensing the instantaneous voltage across the load, a timer, and a comparator. The reactive filter alternately takes in energy from the power source and discharges it into the load. The voltage sensor, timer, and comparator cooperate with a switch to modulate the application of power to the load and to the reactive filter in response to the instantaneous magnitudes of the load voltage and the power source voltage.Type: GrantFiled: October 30, 1996Date of Patent: August 10, 1999Assignee: Philips Electronics North America CorporationInventor: Nai-Chi Lee
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Patent number: 5731701Abstract: To improve testability of analog or mixed analog/digital circuit modules mounted on a carrier, three-way switches are placed at input and output ports of the circuit modules. The switches can operate to establish signal connections between a test bus and core circuits inside the modules. The switches can also establish signal connections between the test bus and glue circuits disposed between the modules.Type: GrantFiled: August 12, 1996Date of Patent: March 24, 1998Assignee: Philips Electronics North America CorporationInventor: Nai-Chi Lee
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Patent number: 5721511Abstract: A pulse width modulation driver is capable of regulating the average voltage applied to a load that is powered from a source having a wide range, e.g. 20 to 80 volts DC, of possible voltages. The driver cyclically interrupts the load current at a frequency which is substantially constant. This is particularly advantageous for driving frequency-sensitive loads such as motors.Type: GrantFiled: July 1, 1996Date of Patent: February 24, 1998Assignee: Philips Electronics North America CorporationInventor: Nai-Chi Lee
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Patent number: 5717329Abstract: To improve testability of analog or mixed analog/digital circuit modules mounted on a carrier, three-way switches are placed at input and output ports of the circuit modules. The switches can operate to establish signal connections between a test bus and core circuits inside the modules. The switches can also establish signal connections between the test bus and glue circuits disposed between the modules.Type: GrantFiled: March 20, 1995Date of Patent: February 10, 1998Assignee: Philips Electronics North America Corp.Inventor: Nai-Chi Lee
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Patent number: 5705925Abstract: To improve testability of analog or mixed analog/digital circuit modules mounted on a carrier, three-way switches are placed at input and output ports of the circuit modules. The switches can operate to establish signal connections between a test bus and core circuits inside the modules. The switches can also establish signal connections between the test bus and glue circuits disposed between the modules.Type: GrantFiled: May 23, 1995Date of Patent: January 6, 1998Assignee: North American Philips CorporationInventor: Nai-Chi Lee
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Patent number: 5581176Abstract: To improve testability of analog or mixed analog/digital circuit modules mounted on a carrier, three-way switches are placed at input and output ports of the circuit modules. The switches can operate to establish signal connections between a test bus and core circuits inside the modules. The switches can also establish signal connections between the test bus and glue circuits disposed between the modules.Type: GrantFiled: May 24, 1993Date of Patent: December 3, 1996Assignee: North American Philips CorporationInventor: Nai-Chi Lee
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Patent number: RE37500Abstract: A system for providing testing capability of individual submodules on an integrated circuit module. A test bus having a plurality of conductors is connected to selected internal ports of said submodules through three-way analog switches. Each three-way analog switch provides the capability to observe and control an internal port through combination of the ON/OFF status of two transmission gates. Test patterns for controlling the transmission gates may be provided by onboard D flip-flops which are externally programmed to control or observe ports of an individual submodule.Type: GrantFiled: November 20, 1996Date of Patent: January 8, 2002Assignee: North American Philips CorporationInventor: Nai-Chi Lee