Abstract: An automatic dead zone time optimization system in a primary-side regulation flyback power supply continuous conduction mode (CCM), including a closed loop formed by a control system, including a single output digital to analog converter (DAC) midpoint sampling module, a digital control module, a current detection module, a dead zone time calculation module and a pulse-width modulation (PWM) driving module, and a controlled synchronous rectification primary-side regulation flyback converter. A primary-side current is sampled using a DAC Sampling mechanism to calculate a secondary-side average current, so as to obtain a primary-side average current and a secondary-side average current, in the case of CCM. A secondary-side current is input into the dead zone time calculation module to obtain a reasonable dead zone time; and the PWM driving module is jointly controlled by a primary-side regulation loop and the obtained dead zone time.

Abstract: A method and an apparatus for reducing noise of a switched reluctance motor, includes: supplying a PWM signal as a driving signal to a driving circuit of a switched reluctance motor; and varying a carrier frequency of the PWM signal as an operation period of the switched reluctance motor varies; if the switched reluctance motor changes phase, determining that the operation period of the switched reluctance motor varies.

Abstract: A method for improving the conversion efficiency of a CCM mode of a flyback resonant switch power supply, comprising: presetting a critical value Tset, calculating a time interval Ttap between adjacent zero points in the current connection time, outputting a shutdown signal at the zero points, and comparing the time interval Ttap with the preset critical value Tset; when Ttap>Tset, controlling the current shutdown time to be less than the shutdown time of the preceding cycle and outputting a start signal; when Ttap=0, controlling the current shutdown time to be greater than the shutdown time of the preceding cycle and outputting a start signal; and when 0<Ttap<=Tset, controlling the current shutdown time to be the same as the shutdown time of the preceding switch cycle and outputting a start signal.

Abstract: An automatic dead zone time optimization system in a primary-side regulation flyback power supply CCM mode, comprising a closed loop formed by a control system, consisting of a single output DAC midpoint sampling module, a digital control module, a current detection module, a dead zone time calculation module and a PWM driving module, and a controlled synchronous rectification primary-side regulation flyback converter. By means of a DAC Sampling mechanism, a primary-side current is sampled to calculate a secondary-side average current, so as to obtain a primary-side average current Imid_p and a secondary-side average current Is(tmid) in the case of CCM; a secondary-side current is input into the dead zone time calculation module to obtain a reasonable dead zone time td; and finally, the PWM driving module is jointly controlled by a primary-side regulation loop and the obtained dead zone time td.

Abstract: A method and an apparatus for reducing noise of a switched reluctance motor, includes: supplying a PWM signal as a driving signal to a driving circuit of a switched reluctance motor; and varying a carrier frequency of the PWM signal as an operation period of the switched reluctance motor varies; if the switched reluctance motor changes phase, determining that the operation period of the switched reluctance motor varies.

Abstract: A method for improving the conversion efficiency of a CCM mode of a flyback resonant switch power supply, comprising: presetting a threshold value Tset, calculating a time interval Ttap between adjacent zero points during a present conducting time, outputting a switch-off signal at zero points, and comparing the time interval Ttap with the preset threshold value Tset; when Ttap>Tset, he present switch-off time to be less than a switch-off time of a previous cycle, outputting a switch-on signal; when Ttap=0, controlling the present switch-off time to be greater than a switch-off time of the previous cycle, outputting a switch-on signal; and when 0<Ttap<=Tset, controlling the present switch-off time to be the same as the switch-off time of the previous switch cycle, outputting a switch-on signal.