Mks Instruments, Inc.

Kaman Electromagnetics Corp.

Alan Millner

Ken Tran

Ilya Bystryak

Madhuwanti Joshi

Igor Elkin

Michael Kishinevsky

Peter P Mongeau

Thomas Alexander

Zaher Daboussi

A transformer-less power supply is provided for ozone generation. The power supply advantageously reduces costs and increases reliability of ozone generators. The power supply provides a first AC voltage from a power source to a resonant circuit and the resonant circuit provides a second AC voltage to the ozone generating unit, the second AC voltage being greater than the first AC voltage. A controller for the power supply that adapts to the resonance of the circuit to provide control with a wide tolerance for the high Q circuit component values of the circuit.

Power supply including transformer-less high voltage power oscillators for ozone generation

A method and apparatus for controlling a power supply to prevent instabilities due to dynamic loads in RF plasma processing systems, operating at frequencies of from 1 MHz and up 1 MHz and above. The apparatus includes a power source, a power converter receiving power from the source, the power converter providing a constant output power controlled by varying at least one of input voltage or switching frequency, and an RF generator receiving constant power from the power converter.

Method and apparatus for preventing instabilities in radio-frequency plasma processing

A control circuit for a switching power supply reacts to an over current condition in the switching power supply to bring its operating point to a safe condition. The control circuit senses both the direction and the magnitude of the load current in the switching power supply, and then uses this sensed information to control the active power switches in the switching power supply. In an over current condition, the switches are controlled to actively drive the load current toward zero, even if the sensed information is delayed or heavily filtered, or the switch signals from the control circuit are delayed in reaching the switches. The resulting operation of the switching power supply is more resistant to abnormal load conditions and is maintained in the presence of transient short circuits or arcs. The switching power supply hardware is also better protected.

Power supply controller to actively drive a load current when the load current exceeds a set point

According to a first aspect, a power supply and a method of providing power for igniting a plasma in a reactive gas generator is provided that includes (i) coupling a series resonant circuit that comprises a resonant inductor and a resonant capacitor between a switching power source and a transformer, the transformer having a transformer primary and a plasma secondary; (ii) providing a substantially resonant AC voltage from the resonant capacitor across the transformer primary, thereby inducing a substantially resonant current within the transformer primary to generate the plasma secondary; and (iii) upon generation of the plasma secondary, the resonant inductor limiting current flowing to the switching power supply. According to another aspect, bipolar high voltage ignition electrodes can be used in conjunction with inductive energy coupling to aid in plasma ignition.

Method and apparatus of providing power to ignite and sustain a plasma in a reactive gas generator

A four quadrant unipolar pulse width modulated (PWM) power conversion circuit for supplying a desired current to an inductive load uses an H-bridge circuit topology with an upper and lower pair of switching elements including a diode in parallel with each of the switching elements to provide a current path from the load to the power source when its respective switching element is non-conductive. A control algorithm generates switching element control signals to cause the instantaneous voltage across the load to alternate between a single polarity voltage and zero for a portion of the output load waveform to cause the average value of the load current to correspond generally with the desired average load current.

Growing community of inventors

Lexington, MA, United States of America

Alan Millner