Tool/software:
Using TL494 IC to do a boost converter .
The input voltage is 100-250V, the output voltage is 300V, full load power is 250W.
The switchin frequency is 300kHz. And this is my schematic 
And this is my MOSFET's Vgs and the output voltage
the green one is output voltage, and the yellow one is PWM waveform.
I want to ask what cause my pwm acting so weried. Sometime it worked sometime it closed.
