hi guys I plan to use TVS diode as snubber for a ac-dc flyback converter, by connecting TVS diode in parallel with the primary winding of the flyback transformer so that TVS diode absorbs the transient energy stored in the leakage inductance of the flyback transformer during turn off of the switch. The rated output voltage of the converter is
50 V dc. The turns ratio of the transformer is 4:1. My rated power of operation is 210 W. Switching frequency is 50KHz in CCM mode. During transient my output voltage can go up to 80 V(worst case), and the current in the switch might go up to 15 A(max during full load in transient). Therefore I would require a TVS diode with a peak pulse power dissipation (Ppp) of about 1.6*80*4*15 =7680 W with rated working peak voltage (Vwm) of 80*4= 360. Since I could only get TVS diodes with Ppp of 1500 W. I intend to put six TVS diodes of 1500 W Ppp and Vwm 0f 60 V in series. Can anyone suggest weather this idea will work, and will any special measures have to be undertaken to for heat dissipation if the whole ckt (other than flyback t/f) has to be implemented on a pcb.- posted
16 years ago