Quasi-resonance testing circuit and quasi-resonance control circuit of inverter

Abstract

The invention provides a quasi-resonance testing circuit of an inverter. The quasi-resonance testing circuit includes a divider circuit which makes one end coupled with a source extreme of a host switch tube of the inverter, and the other end coupled with a public earth terminal with a drain extreme of the host switch tube together so as to output a source-drain voltage of the host switch tube in proportion based on an input voltage. The quasi-resonance testing circuit also includes a first voltage selecting switch tube. The source extreme of the first voltage selecting switch tube is coupled with a high voltage terminal after passing through a third resistor, and the drain extreme is coupled with the other end of the divider circuit. A grid terminal is coupled with a voltage output terminal of the divider circuit, and is used to switch on or off the voltage output terminal in according to an output voltage of the divider circuit. Correspondingly, the invention also provides a quasi-resonance control circuit of the inverter. The element resistance of the divider circuit of the invention is changeable, and can be controlled by an input voltage, thus enabling the host switch tube to adjust a quasi-resonance threshold voltage automatically based on the input voltage, and consequently making the quasi-resonance function available within a complete input voltage range, and effectively reducing energy loss and increasing working efficiency.

Description

technical field [0001] The invention relates to the technical field of quasi-resonance detection and control, in particular, the invention relates to a quasi-resonance detection circuit and a quasi-resonance control circuit of an inverter. Background technique [0002] In the existing inverter field, quasi-resonant technology is a widely used method to increase efficiency, improve reliability and reduce cost. It enables the main switching tube of the inverter to be turned on at the valley of the voltage at both ends, thereby reducing the energy loss of the main switching tube. By controlling the turn-on and turn-off time of the main switching tube, the quasi-resonant switching function can be realized, thereby effectively reducing energy loss and improving efficiency. In addition, softer switching can improve the EMI characteristics of the power supply, allowing designers to reduce the number of filters used, thereby reducing costs. [0003] The prior art generally utilize...

AI Technical Summary

Problems solved by technology

If the value of this setting is increased to ensure that the valley voltage is lower than this value at high input voltage, then at low input voltage, the main switches will also be turned on at this set value instead of at the lower value they could have reached. Turning it on again causes more energy loss and reduces work efficiency

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