Patents by Inventor Franki Ngai Kit Poon
Franki Ngai Kit Poon 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).
-
Patent number: 11754611Abstract: An electromagnetic interference suppression circuit and a related sensing circuit. The sensing circuit includes an input and an output operatively coupled with the input. The input is adapted to be connected on a power line and in series between a load and a shunt circuit connected across power lines between a power source and the load. The output is adapted to provide a signal (Vs) associated with an electromagnetic interference signal (Vn) generated by or at the load and arranged to be experienced by the shunt circuit. The signal (Vs) can be used for determining a suppression signal (Vn?) for reducing, or substantially eliminating, the electromagnetic interference signal (Vn). The electromagnetic interference suppression circuit includes the sensing circuit, a regulator circuit, and a controlled signal source.Type: GrantFiled: July 21, 2020Date of Patent: September 12, 2023Assignee: AnApp Technologies LimitedInventors: Franki Ngai Kit Poon, Peter On Bon Chan
-
Publication number: 20220026480Abstract: An electromagnetic interference suppression circuit and a related sensing circuit. The sensing circuit includes an input and an output operatively coupled with the input. The input is adapted to be connected on a power line and in series between a load and a shunt circuit connected across power lines between a power source and the load. The output is adapted to provide a signal (Vs) associated with an electromagnetic interference signal (Vn) generated by or at the load and arranged to be experienced by the shunt circuit. The signal (Vs) can be used for determining a suppression signal (Vn?) for reducing, or substantially eliminating, the electromagnetic interference signal (Vn). The electromagnetic interference suppression circuit includes the sensing circuit, a regulator circuit, and a controlled signal source.Type: ApplicationFiled: July 21, 2020Publication date: January 27, 2022Inventors: Franki Ngai Kit POON, Peter On Bon CHAN
-
Patent number: 10396656Abstract: A control circuit for suppressing electromagnetic interference signal has an input and an output and a variable gain filter circuit with a first gain factor that is variable. The variable gain filter circuit receives a signal indicative of an electromagnetic interference signal and outputs a signal to a controlled signal source, which a second gain factor. The control circuit also has a controller operably connected to the variable gain filter circuit. The controller receives a signal indicative of an output signal at the output of the control circuit and outputs a control signal to the variable gain filter circuit. The control signal is based on the signal indicative of the output signal at the output of the control circuit, and the control signal controls the first gain factor and reduces the electromagnetic interference signal.Type: GrantFiled: November 9, 2018Date of Patent: August 27, 2019Assignee: AnApp Technologies LimitedInventors: Franki Ngai Kit Poon, Peter On Bon Chan
-
Patent number: 7567040Abstract: An efficient power driver for color light emitting diodes (LED) is disclosed for driving multiple LEDs for producing different desired colors. Such LED combinations comprising LEDs with different primary colors are suitable for implementing pixels in displaying a digitized image. This disclosed invention provides switching power conversion embodiments such that a single apparatus drives different color LEDs. Furthermore, the disclosed invention provides configurations with and without input to output isolation while enabling control of the current through each LED, for instance by an inductor or operating condition.Type: GrantFiled: October 24, 2006Date of Patent: July 28, 2009Assignee: The University of Hong KongInventors: Man Hay Pong, Franki Ngai Kit Poon, Joe Chui Pong Liu
-
Patent number: 7368883Abstract: In fluorescent lamp lighting, it is required that when the lamp reaches its end of life there has to be some mechanism to shut down the power supply to the lamp for safety. In the present invention, an apparatus is proposed to fulfill this requirement. This invention comprises of a lamp, means to sense currents at the lamp filaments and the imbalance of the currents is detected and turn off the power source to the lamp. Several embodiments are included to illustrate the execution of this invention.Type: GrantFiled: April 12, 2006Date of Patent: May 6, 2008Assignee: Power ELab Ltd.Inventors: Yick Po Chan, Franki Ngai Kit Poon
-
Patent number: 7178971Abstract: An efficient power driver for color light emitting diodes (LED) is disclosed for driving multiple LEDs for producing different desired colors. Such LED combinations comprising LEDs with different primary colors are suitable for implementing pixels in displaying a digitized image. This disclosed invention provides switching power conversion embodiments such that a single apparatus drives different color LEDs. Furthermore, the disclosed invention provides configurations with and without input to output isolation while enabling control of the current through each LED, for instance by an inductor or operating condition.Type: GrantFiled: December 14, 2001Date of Patent: February 20, 2007Assignee: The University of Hong KongInventors: Man Hay Pong, Franki Ngai Kit Poon, Joe Chui Pong Liu
-
Patent number: 7122972Abstract: An AC to AC power conversion apparatus with constant power feeding characteristics to fluorescent lamp or FD lamp is described. The constant power characteristic is achieved by discontinuous mode operation of capacitor coupled in series with the load. Packets of energy are pumped out to the load in each switching cycle, regardless of the resonant characteristics. The dependence of the input power on the square of the supply voltage make the input resistive and produces good power factor automatically. The lamp load is dimmable by external phase control dimmer like resistive incandescent lamps. Multiple lamp loads with different power rating can be integrated by adding more sets of said capacitors and associated components.Type: GrantFiled: March 10, 2004Date of Patent: October 17, 2006Assignee: University of Hong KongInventors: Franki Ngai Kit Poon, Man Hay Pong, Joe Chiu Pong Liu
-
Patent number: 6815937Abstract: A fast transient response converter is disclosed which makes use of stepping inductor in a switching converter to speed up output voltage response under fast transient condition. The inductive element in a switching converter is replaced by two series or parallel inductive elements, one of which has a smaller value of inductance than the other. During the fast transient period, the inductor with larger inductance value will be shorted to a voltage source. The total inductance will be greatly reduced and thus allows rapid current change during the transient change.Type: GrantFiled: October 24, 2002Date of Patent: November 9, 2004Assignee: The University of Hong KongInventors: Franki Ngai Kit Poon, Man Hay Pong, Joe Chui Pong Liu
-
Patent number: 6812679Abstract: A power converter includes a boost converter, a DC/DC converter and a coupler chain. The boost converter receives a rectified AC input and generates a high voltage output. The boost converter includes a zero-voltage-switching transistor that is operable to adjust the power factor of the rectified AC input to generate the high voltage output. The DC/DC converter is coupled to the high voltage output of the boost converter and is configured to generate a regulated output voltage. The DC/DC converter includes a complementary pair of zero-voltage-switching transistors that are operable to regulate the high voltage output of the boost converter to generate the regulated output voltage.Type: GrantFiled: May 27, 2003Date of Patent: November 2, 2004Assignee: The University of Hong KongInventors: Joe Chui Pong Liu, Franki Ngai Kit Poon, Man Hay Pong
-
Publication number: 20040080965Abstract: A fast transient response converter is disclosed which makes use of stepping inductor in a switching converter to speed up output voltage response under fast transient condition. The inductive element in a switching converter is replaced by two series or parallel inductive elements, one of which has a smaller value of inductance than the other. During the fast transient period, the inductor with larger inductance value will be shorted to a voltage source. The total inductance will be greatly reduced and thus allows rapid current change during the transient change.Type: ApplicationFiled: October 24, 2002Publication date: April 29, 2004Inventors: Franki Ngai Kit Poon, Man Hay Pong, Joe Chui Pong Liu
-
Method and system for providing a DC voltage with low ripple by overlaying a plurality of AC signals
Patent number: 6697266Abstract: An AC-DC converter that includes a plurality of power conversion units that overlay their signals to generate a DC signal with low voltage level, small voltage and current ripples, but high DC current. The DC signal is further filtered by a LC low pass filter to further minimize the ripples before output to the load. In one embodiment, the plurality of power conversion units is preferably powered by a plurality of input pulse generators. In an alternative embodiment, the power conversion units is powered by a input pulse generator circuit that includes a plurality of n-channel MOSFETs arranged in a full bridge configuration whose gate voltages are controlled by a plurality of pulse generators.Type: GrantFiled: March 4, 2002Date of Patent: February 24, 2004Assignee: University of Hong KongInventors: Franki Ngai Kit Poon, Man Hay Pong, Joe Chui Pong Liu -
Publication number: 20030210024Abstract: A power converter includes a boost converter, a DC/DC converter and a coupler chain. The boost converter receives a rectified AC input and generates a high voltage output. The boost converter includes a zero-voltage-switching transistor that is operable to adjust the power factor of the rectified AC input to generate the high voltage output. The DC/DC converter is coupled to the high voltage output of the boost converter and is configured to generate a regulated output voltage. The DC/DC converter includes a complementary pair of zero-voltage-switching transistors that are operable to regulate the high voltage output of the boost converter to generate the regulated output voltage.Type: ApplicationFiled: May 27, 2003Publication date: November 13, 2003Inventors: Joe Chui Pong Liu, Franki Ngai Kit Poon, Man Hay Pong
-
Publication number: 20030165069Abstract: An AC-DC converter that includes a plurality of power conversion units that overlay their signals to generate a DC signal with low voltage level, small voltage and current ripples, but high DC current. The DC signal is further filtered by a LC low pass filter to further minimize the ripples before output to the load. In one embodiment, the plurality of power conversion units is preferably powered by a plurality of input pulse generators. In an alternative embodiment, the power conversion units is powered by a input pulse generator circuit that includes a plurality of n-channel MOSFETs arranged in a full bridge configuration whose gate voltages are controlled by a plurality of pulse generators.Type: ApplicationFiled: March 4, 2002Publication date: September 4, 2003Inventors: Franki Ngai Kit Poon, Man Hay Pong, Joe Chui Pong Liu
-
Publication number: 20030112229Abstract: An efficient power driver for color light emitting diodes (LED) is disclosed for driving multiple LEDs for producing different desired colors. Such LED combinations comprising LEDs with different primary colors are suitable for implementing pixels in displaying a digitized image. This disclosed invention provides switching power conversion embodiments such that a single apparatus drives different color LEDs. Furthermore, the disclosed invention provides configurations with and without input to output isolation while enabling control of the current through each LED, for instance by an inductor or operating condition.Type: ApplicationFiled: December 14, 2001Publication date: June 19, 2003Inventors: Man Hay Pong, Franki Ngai Kit Poon, Joe Chui Pong Liu
-
Patent number: 6580259Abstract: An AC/DC power converter includes a pair of input terminals, a boost unit, a DC/DC converter, a coupler chain, and a discharge chain. The pair of input terminals connect to a pulsating DC source. The boost unit is coupled to the input terminals and generates a voltage higher than the voltage at the input terminals. The DC/DC converter couples to the boost unit and includes a set of series switches coupled to the primary side of a transformer through a series inductor and capacitor. The DC/DC converter further includes a secondary winding coupled to the transformer and coupled to a rectifier and filter configuration. The coupler chain couples the boost unit to the DC/DC converter. The discharge chain couples the coupler chain to the high voltage source generated by the boost unit. Control pulses synchronize the series switches so that a resonant current flows in the coupler chain and the discharge chain such that the switches can be turned on and off while voltages across the switches are substantially zero.Type: GrantFiled: January 7, 2002Date of Patent: June 17, 2003Assignee: The University of Hong KongInventors: Joe Chui Pong Liu, Franki Ngai Kit Poon, Man Hay Pong
-
Publication number: 20020110012Abstract: An AC/DC power converter includes a pair of input terminals, a boost unit, a DC/DC converter, a coupler chain, and a discharge chain. The pair of input terminals connect to a pulsating DC source. The boost unit is coupled to the input terminals and generates a voltage higher than the voltage at the input terminals. The DC/DC converter couples to the boost unit and includes a set of series switches coupled to the primary side of a transformer through a series inductor and capacitor. The DC/DC converter further includes a secondary winding coupled to the transformer and coupled to a rectifier and filter configuration. The coupler chain couples the boost unit to the DC/DC converter. The discharge chain couples the coupler chain to the high voltage source generated by the boost unit. Control pulses synchronize the series switches so that a resonant current flows in the coupler chain and the discharge chain such that the switches can be turned on and off while voltages across the switches are substantially zero.Type: ApplicationFiled: January 7, 2002Publication date: August 15, 2002Inventors: Joe Chui Pong Liu, Franki Ngai Kit Poon, Man Hay Pong
-
Patent number: 6188209Abstract: A fast transient response power converter is disclosed which makes use of a variable inductor to speed up the converter's output voltage response under fast transient conditions. The inductive element in a switching converter is replaced by two series or parallel inductive elements of which one has a smaller inductance value and the other has a larger inductance value. During the fast transient condition, the total inductance is greatly reduced to allow rapid current change during the transient condition.Type: GrantFiled: February 7, 2000Date of Patent: February 13, 2001Assignee: University of Hong KongInventors: Franki Ngai Kit Poon, Man Hay Pong, Joe Chui Pong Liu
-
Patent number: 6018469Abstract: A switch mode power converter achieving high efficiency through zero voltage switching (ZVS) by using an auxiliary switch, a capacitor, an auxiliary winding and an inductor. The technique can be applied to a boost, buck-boost, buck, isolated forward or isolated flyback converter. The auxiliary switch is turned on before the main power switch turns on, and the capacitor provides voltage to energize the inductor and force current to flow into the auxiliary winding. The current is transformed by the main winding and discharges the capacitance across main power switch to zero volts before the main switch turns on. Hence ZVS is obtained and can greatly reduce the switching loss of the main power switch.Type: GrantFiled: December 19, 1997Date of Patent: January 25, 2000Assignee: Computer Products, Inc.Inventor: Franki Ngai Kit Poon
-
Patent number: 5995383Abstract: An AC-to-DC power converter draws input current through an inductor. When the input voltage of the converter is sufficiently high and the switch of the converter is on, current flows into the converter, through the inductor, to the tap of a transformer, through a first primary winding of the transformer, and through the switch. When the switch is then turned off, current continues to flow through the inductor and to the tap of the transformer but then flows through a second primary of the transformer and into a storage capacitor. Energy stored in the storage capacitor is transferred to the load when it is not possible to obtain sufficient energy from the input current to supply the load. The AC-to-DC converter has very few circuit components and low input current harmonics.Type: GrantFiled: September 27, 1996Date of Patent: November 30, 1999Assignee: Computer Products, Inc.Inventors: Franki Ngai Kit Poon, Robert Chun Fung Lee, Fu-Sheng Tsai, Francis Man Shuen Ho
-
Patent number: 5880940Abstract: A switch mode power converter achieving high efficiency through zero voltage switching (ZVS) by using an auxiliary switch, a capacitor, an auxiliary winding and an inductor. The technique can be applied to a boost, buck-boost, buck, isolated forward or isolated flyback converter. The auxiliary switch is turned on before the main power switch turns on, and the capacitor provides voltage to energize the inductor and force current to flow into the auxiliary winding. The current is transformed by the main winding and discharges the capacitance across main power switch to zero volts before the main switch turns on. Hence ZVS is obtained and can greatly reduce the switching loss of the main power switch.Type: GrantFiled: February 21, 1997Date of Patent: March 9, 1999Assignee: Computer Products, Inc.Inventor: Franki Ngai Kit Poon