2020-05-19 05:50 PM
Input: Single-phase AC70-500V
Output: DC24V5W
Output diode voltage drop: 1.25V
1�?My design idea is this, design the transformer to work in CCM mode (current ripple coefficient 0.85) at the lowest input voltage and full load, and enter DCM mode after the voltage rises. The following are the transformer parameters I designed. Is it reasonable?
Estimated efficiency:75%
Core:PC40 EE19 AE:23mm²
Dmax:0.512
Number of primary turns:160
Number of secondary turns:45
VCC winding:33
Primary inductance:3.13mH
Primary wire diameter:0.2mm
VCC wire diameter:0.2mm
secondary wire diameter:0.36mm
Sandwich wrap
2�?In addition, it is generally said that the maximum duty cycle of the flyback cannot exceed 50%, because subharmonic oscillation is prone to occur, may I ask if the duty cycle of VIPER26K can exceed 50% when designing the transformer, is there internal slope compensation?