Power supplies having protection circuits

A power supply circuit for supplying alternating power to a load, comprising:

• a source of direct current (DC) voltage;
• a full-bridge inverter for receiving the DC input voltage and for generating an alternating current (AC) output signal, the full bridge inverter comprising a pair of half bridges;
• a first harmonic filter at the output of each respective half bridge, the harmonic filter filtering out predetermined harmonic components of the AC signal to generate a filtered AC signal;
• and
• an output circuit at the combined output of the first harmonic filters, the output circuit receiving the filtered AC signal and feeding the filtered AC signal to a load, wherein the output circuit includes first and second rectifiers connected relative to a point in the output circuit such that if the inverter attempts to drive the point to a voltage which exceeds one of a predetermined first and second voltage, a respective one of the first and second rectifiers conducts to cause at least one of voltage and current to return to the source of DC voltage.

A power supply circuit for supplying alternating power to a load, comprising:

• a source of direct current (DC) voltage;
• a pair of single ended inverters for receiving the DC input voltage and for generating an alternating current (AC) output signal, the single ended inverters formed in a full bridge configuration;
• a first harmonic filter at the output of each respective half bridge, the harmonic filter filtering out predetermined harmonic components of the AC signal to generate a filtered AC signal;
• and
• an output circuit at the combined output of the first harmonic filters, the output circuit receiving the filtered AC signal and feeding the filtered AC signal to a load, wherein the output circuit includes first and second rectifiers connected relative to a point in the output circuit such that if the inverter attempts to drive the point to a voltage which exceeds one of a predetermined first or second voltage, a respective one of the first and second rectifiers conducts to cause at least one of voltage and current to return to the source of DC voltage.

A power supply circuit for supplying alternating power to a load, comprising:

• a source of direct current (DC) voltage;
• a first plurality of single ended inverters arranged in series between first and second rails of the DC voltage source, the first plurality of single ended inverters forming a first half of a bridge configuration, the first half of the bridge having a first combined output;
• a second plurality of single ended inverters arranged in series between first and second rails of the DC voltage source, the second plurality of single ended inverters forming a second half of a bridge configuration, the second half of the bridge having a second combined output;
• a first harmonic filter at the output of each respective bridge half, the harmonic filter filtering out predetermined harmonic components of the AC signal to generate a filtered AC signal;
• and
• an output circuit at the combined output of the first harmonic filters, the output circuit receiving the filtered AC signal and feeding the filtered AC signal to a load, wherein the output circuit includes first and second rectifiers connected relative to a point in the output circuit such that if the inverter attempts to drive the point to a voltage which exceeds one of a predetermined first and second voltage, a respective one of the first and second rectifiers conducts to cause at least one of voltage and current to the source of DC voltage.

A power supply circuit for supplying alternating power to a load, comprising:

• a source of direct current (DC) voltage;
• a full-bridge inverter for receiving the DC input voltage and for generating an alternating current (AC) output signal, the full-bridge inverter comprising a pair of half-bridges;
• a harmonic filter at the output of the inverter, the harmonic filter filtering out predetermined harmonic components of the AC signal to generate a filtered AC signal;
• and
• an output circuit at the output of the harmonic filter for receiving the filtered AC signal and feeding the filtered AC signal to a load, wherein the output circuit includes at least one rectifier connected relative to a point in the output circuit such that if the inverter attempts to drive the point to a voltage which exceeds one of a predetermined first and second voltage, the at least one rectifier conducts to cause at least one of voltage and current to dissipate, wherein the predetermined first and second voltages are other than the voltages of respective positive and negative rails of the DC voltage source.

A control system for a power generator, comprising:

• a circuit for receiving an AC signal and converting the AC signal to a DC voltage signal;
• a power amplifier including:
• a full bridge inverter for receiving the DC voltage signal and for generating an AC output signal, the full bridge having first and second halves, and
• an output circuit, the output circuit receiving the filtered AC signal and feeding the filtered AC signal to a load, wherein the output circuit includes first and second rectifiers connected relative to a point in the output circuit such that if the inverter attempts to drive the point to a voltage which exceeds one of a predetermined first and second voltage, a respective one of the first and second rectifiers conducts to cause at least one of voltage and current to return to the inverter;
• and
• an output sense circuit for determining a power of the output signal the output sense circuit generating a sense signal;
• and
• a phase modulator for varying the relative phases of the full bridge to vary the output power in accordance with the sense signal.

A plasma control system comprising:

• a plasma chamber excited by a radio frequency (RF) signal;
• a plasma controller for measuring operating conditions of the plasma chamber and generating control signals for varying conditions within the plasma chamber;
• and
• a RF generator for generating an RF signal to the plasma chamber, the RF generator including:
• a RF controller, the RF controller receiving the control signal from the plasma controller an generating a power supply control signal, and
• a power supply for receiving the power supply control signal and generating a RF signal in accordance with the power supply control signal,
• wherein the power supply includes a protection circuit including first and second rectifiers connected relative to a predetermined point such that such that if the power supply attempts to drive the predetermined point to a voltage which exceeds one of a predetermined first and second voltage, a respective one of a first and second rectifiers conducts.

A power supply circuit for supplying alternating power to a load, comprising:

• a source of direct current (DC) voltage;
• an inverter for receiving the DC input voltage and for generating an alternating current (AC) output signal for input to a load;
• an output circuit at the output of the inverter;
• and
• a return circuit connected to a point in the output circuit such that if the voltage at the point exceeds one of a predetermined first and second voltage, the return circuit conducts to cause at least one of voltage and current to return to the source of DC voltage.

A power supply circuit for supplying alternating power to a load, comprising:

• a source of direct current (DC) voltage;
• an inverter for receiving the DC input voltage and for generating an alternating current (AC) output signal for input to a load;
• an output circuit at the output of the inverter;
• and
• a dissipation circuit connected to a point in the output circuit such that if the voltage at the point exceeds one of a predetermined first and second voltage, the dissipation circuit conducts to cause at least one of voltage and current to dissipate.