A transformer anti-saturation control system for flyback switching power supply

Abstract

The invention discloses a transformer anti-saturation control system for a flyback switching power supply. The transformer anti-saturation control system comprises an oscillator used for outputting an open signal to open a power tube when the flyback switching power supply works; a peak value comparator used for transmitting a delay signal to a delay circuit when the sampling voltage of a CS sampling resistor is greater than a first voltage threshold; the delay circuit used for transmitting a detection signal to a saturation detection circuit according to the delay signal after delaying the scheduled time; an analog adder used for superposing the first voltage threshold and the preset superimposed voltage, and obtaining a second threshold voltage; the saturation detection circuit used for detecting the sampling voltage and the second threshold voltage when receiving the detection signal, and transmitting a first control signal to the oscillator when the sampling voltage is greater than the second threshold voltage; and the oscillator is further used for reducing the frequency of the open signal when receiving the first control signal, so as to prolong the turn-off time of the power tube. The transformer anti-saturation control system for the flyback switching power supply provided by the invention can reset a transformer in time when the transformer is in a saturation state.

Description

technical field [0001] The invention relates to the technical field of power supplies, in particular to a transformer anti-saturation control system of a flyback switching power supply. Background technique [0002] With the rapid development of integrated circuits, flyback switching power supplies are commonly used in power supply systems. In the application of flyback switching power supplies, sometimes transformer saturation occurs due to transformer design errors, such as due to transformer design parameters. Design deviations lead to a small transformer model, which will easily cause the transformer to fail to reset in time during each switching cycle, so that the transformer will be in a long-term saturated working state. If the transformer cannot be reset in time in a saturated state (that is, it is in a saturated state for a long time), it will cause damage to the entire system loop, and even accidents such as explosions and fires. Contents of the invention [000...

AI Technical Summary

Problems solved by technology

[0002] With the rapid development of integrated circuits, flyback switching power supplies are commonly used in power supply systems. In the application of flyback switching power supplies, sometimes transformer saturation occurs due to transformer design errors, such as due to transformer design parameters. The design deviation leads to a small transformer model, which will easily cause the transformer to fail to reset in time during each switching cycle, so that the transformer will be in a long-term saturated working state

If the transformer cannot be reset in time in a saturated state (that is, it is in a saturated state for a long time), it will cause damage to the entire system loop, and even accidents such as explosions and fires

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