Current-mode resonant inverter circuit

A current-mode resonant inverter circuit comprising:

• a step-up transformer;
• a secondary side circuit connected to a secondary winding of the step-up transformer, the secondary side circuit comprising a capacitive component, a resonant circuit being formed as a result of a leakage inductance of the step-up transformer secondary winding and the capacitive component in the secondary side circuit;
• an auxiliary resonance capacitor included in the capacitive component of the step-up transformer secondary circuit;
• current phase detecting means for detecting a current flowing through the auxiliary resonance capacitor;
• and
• switching means for determining a switching timing in response to an output from the current phase detecting means,
• wherein:
• one end of a primary winding of the step-up transformer is connected to a power source side;
• the other end of the primary winding is connected to a switched snubber circuit;
• the switched-snubber circuit includes a pair of transistors different from each other in polarity, the bases or gates of the pair of transistors being connected to each other;
• the switching means drives the step-up transformer primary winding;
• a parallel loaded serial resonant circuit is formed as a result of the capacitive component including the auxiliary resonance capacitor and the leakage inductance of the step-up transformer secondary winding;
• and
• the current-mode resonant inverter circuit oscillates self-excitedly at a resonance frequency of the parallel loaded serial resonant circuit.

A current-mode resonant inverter circuit comprising:

• a step-up transformer;
• and
• a secondary side circuit connected to a secondary winding of the step-up transformer, the secondary side circuit comprising a capacitive component, a resonant circuit being formed as a result of a leakage inductance of the step-up transformer secondary winding and the capacitive component in the secondary side circuit,
• wherein:
• one end of a primary winding of the step-up transformer is connected to a power source side through a primary winding of a current transformer;
• the other end of the primary winding is connected to a switched snubber circuit;
• and
• the switched-snubber circuit includes a pair of transistors different from each other in polarity, the bases or gates of the pair of transistors being connected to each other,
• the pair of transistors are connected to a secondary winding of the current transformer;
• one collector of the pair of transistors is connected to the primary winding of the current transformer, and the other collector of the pair of transistors is connected to the current transformer primary winding through a capacitor.

A current-mode resonant inverter circuit comprising:

• a step-up transformer;
• and
• a secondary side circuit connected to a secondary winding of the step-up transformer, the secondary side circuit comprising a capacitive component, a resonant circuit being formed as a result of a leakage inductance of the step-up transformer secondary winding and the capacitive component in the secondary side circuit,
• wherein:
• one end of a primary winding of the step-up transformer is connected to a power source side;
• the other end of the primary winding is connected to a switched snubber circuit through a current detecting element and an amplifier circuit;
• and
• the switched-snubber circuit includes a pair of transistors different from each other in polarity, the bases or gates of the pair of transistors being connected to each other,
• the pair of transistors are connected to the current detecting element and amplifier circuit;
• one collector of the pair of transistors is connected to the current detecting element and amplifier circuit, and the other collector of the pair of transistors is connected to the current detecting element and amplifier circuit through a capacitor.

A current-mode resonant inverter circuit comprising:

• a first choking coil;
• a second choking coil;
• a secondary side circuit, the secondary side circuit comprising a capacitive component and the second choking coil, a resonant circuit being formed based on the second choking coil and the capacitive component in the secondary side circuit;
• an auxiliary resonance capacitor included in the capacitive component of the secondary side circuit;
• current phase detecting means for detecting a current flowing through the auxiliary resonance capacitor;
• and
• switching means for determining a switching timing in response to an output from the current phase detecting means,
• wherein:
• one end of the first choking coil is connected to a power source side;
• the other end of the first choking coil is connected to a switched snubber circuit;
• the switched-snubber circuit includes a pair of transistors different from each other in polarity, the bases or gates of the pair of transistors being connected to each other,
• a parallel loaded serial resonant circuit is formed as a result of the capacitive component including the auxiliary resonance capacitor and the inductance of the second choking coil;
• and
• the current-mode resonant inverter circuit oscillates self-excitedly at a resonance frequency of the parallel loaded serial resonant circuit.

A current-mode resonant inverter circuit comprising:

• a first choking coil;
• and
• a secondary side circuit, the secondary side circuit comprising a capacitive component and a second choking coil, a resonant circuit being formed based on the second choking coil and the capacitive component in the secondary side circuit,
• wherein:
• one end of the first choking coil is connected to a power source side;
• the other end of the first choking coil is connected to a switched snubber circuit through a primary winding of a current transformer;
• and
• the switched-snubber circuit includes a pair of transistors different from each other in polarity, the bases or gates of the pair of transistors being connected to each other,
• the pair of transistors are connected to a secondary winding of the current transformer;
• one collector of the pair of transistors is connected to the primary winding of the current transformer, and the other collector of the pair of transistors is connected to the current transformer primary winding through a capacitor.