U.S. Patents

 

1.     G. Biyalacki and S.K. Mazumder, {Room monitoring and lighting system}, USPTO Patent# 7,268,682, awarded on September 11, 2007.

 

Abstract: A system for improving the safety of a room occupied by a patient includes a sensor for monitoring when the patient is out of bed. The sensor sends a signal that gives an alert to a care giver that the patient is out of bed. Lights in the room are slowly illuminated to provide light for the patient. A second sensor may sense when the patient has returned to bed and correspondingly dim the lights. The history of the patient being in and out of bed, and of the care giver responding to alerts may be recorded in a log. A programmable micro controller is used to control the system.

 

2.     S.K. Mazumder, R.K. Burra, and K. Acharya, {Power conditioning system for energy sources}, USPTO Patent# 7,372,709 B2, awarded on May 13, 2008. (Technology exclusively licensed)

 

Abstract: Apparatus for conditioning power generated by an energy source includes an inverter for converting a DC input voltage from the energy source to a square wave AC output voltage, and a converter for converting the AC output voltage from the inverter to a sine wave AC output voltage.

 

3.     S.K. Mazumder and S.K. Pradhan, {Fuel-cell based power generating system having power conditioning apparatus}, USPTO Patent# 7,808,129 B2, awarded on October 5, 2010.

 

Abstract: A power conditioner includes power converters for supplying power to a load, a set of selection switches corresponding to the power converters for selectively connecting the fuel-cell stack to the power converters, and another set of selection switches corresponding to the power converters for selectively connecting the battery to the power converters. The power conveners output combined power that substantially optimally meets a present demand of the load.

 

4.     S.K. Mazumder and R. Huang, {Multiphase converter apparatus and method}, USPTO Patent# 7,768,800 B2, awarded on Aug 3, 2010.

 

Abstract: An ac/ac converter for accepting a pulsating dc input with encoded sinusoidal modulation and providing a multiphase modulated output. The converter comprises a bridge including a plurality of switches having switch legs for modulating the pulsating dc input at a carrier frequency over a plurality of phases. The bridge is coupled at one end to a pulsating dc source and coupled at another end to a modulated signal output. A controller is provided for the plurality of switches for causing, for each of the plurality of phases, under unity power factor, one of the switch legs to modulate the pulsating dc input at the carrier frequency while the other switch legs do not modulate the pulsating dc input at the carrier frequency.

 

5.     S.K. Mazumder and T. Sarkar, {Optically-triggered multi-stage power system and devices}, U.S. Patent Number 8183512, awarded on May 22, 2012.

 

Abstract: A multi-stage optically-triggered power system. At least one triggering stage is responsive to at least one optical trigger to directly create photogeneration of carriers in the at least one triggering stage and thus generate at least one output signal. At least one main power device stage coupled to the at least one triggering stage is responsive to the at least one generated output signal to activate the at least one main power device stage. The at least one triggering stage and the at least one main power device stage may be monolithically integrated.

 

6.     S.K. Mazumder and T. Sarkar, {Optically-triggered power system and devices}, USPTO Patent# 8,294,078, awarded on October 23, 2012.

 

Abstract: A power device is provided in an optically-triggered power system having a controller for generating electrical control signals and a converter for converting the electrical control signals to optical control signals. The power device includes a pair of terminals and a P-body region provided adjacent an N+ source region. An optical window is provided at least partially over the P-body region, and an N? drift region is provided between the two terminals. The P-body region causes current to conduct between the first and second terminal through the N? drift region when an optical control signal is incident on the optical window.

 

7.     S.K. Mazumder, {Photonically activated single bias fast switching integrated thyristor}, USPTO Patent# US 8796728 B2, awarded on August 5, 2014.

 

Abstract: Preferred embodiments of the invention include a thyristor core that is single biased by a source, such as a power source (or a portion thereof) that is being switched through the thyristors. An optically activated transistor that is preferably a minority carrier device is in series with the thyristor core. The thyristor core has an optically activated gate. The turn-off of the thyristor can be accelerated by the turn-on (conduction state) of a gate switch, which ensures a unity gain turn-off of the core thyristor.

 

8.     S.K. Mazumder, {Zero-voltage switching scheme for high-frequency converter}, USPTO Patent# US 8559193 B2, awarded on October 15, 2013.

 

Abstract: Method for operating an ac/ac converter circuit for a high-frequency-link converter. The ac/ac converter circuit converts an ac input voltage to an ac output voltage. When the ac input voltage is zero, each of a pair of switches for both first and second arms are caused to be on. Current flows through the first arm along a first direction and through the second arm along a second, opposite direction. Next, when the ac input voltage is zero, a selected switch in the second arm is caused to be turned off. The position of the switches can be maintained as the ac input voltage transitions to a dc level, reaches the dc level, approaches zero, and again reaches zero. When the ac input voltage again reaches zero, the selected switch for the second arm is caused to be turned on.

 

9.     S.K. Mazumder, {Scalable single-stage differential power converter}, USPTO Patent# 9379640, awarded on June 28, 2016.

 

Abstract: An embodiment of the invention is a scalable single stage differential power converter. The inverter can be implemented in signal, split and multi-phases. A multiphase converter can be achieved with only three modules. Integrated magnetics used in preferred embodiments of the invention mitigate the DC component of the steady-state dynamics and can be extended to AC ripple mitigation. Control architectures in preferred embodiments can mitigate higher order harmonics in steady state dynamics. Embodiments of the invention also provide scalability for voltage and current source topologies.

 

10. X. Wang, S.K. Mazumder, and W. Shi, {Insulated-gate photoconductive semiconductor switch}, USPTO Patent# 9543462 B2, awarded on January 10, 2017.

 

Abstract: This present invention provides a novel photoconductive semiconductor switch (PCSS) comprising: a semi-insulating substrate, an anode formed on the upper surface of said semi-insulating substrate, a first n-type doped layer formed on the lower surface of said semi-insulating substrate, a p-type doped layer formed on said first n-type doped layer, a second n-type doped layer formed on said p-type doped layer, a cathode formed on said second n-type doped layer, several recesses facing towards said first n-type doped layer and vertically extending into a part of said first n-type doped layer, an insulating layer formed on said second n-type doped layer and on the walls and the bottoms of said recesses, a gate electrode consisting of two parts, one part of the which formed on said insulating layer on the walls and the bottoms of recesses, and the other part of the which formed on a part of the insulating layer on the second n-type doped layer for electrically connecting the part of the gate electrode on the reces,

 

11. S.K. Mazumder and A. Gupta, {Sequential co-transmission of high-frequency power and data signals}, USPTO utility patent application number 62616501, 2018. (Original application submitted in September 2017)