hi everyone
i use this schematic to build a half bridge power supply.
but i have some problems and need some helps.
first problem is feedback.i think this feedback is not good beacause whit this feedback transformer produce a noisy sound like"tik-tik-tik"about twice every second.
i read some where this feed back dosn't control duty cycle and it just turn pwm on or off but i need a feedback that control duty cycle
without feedback there is no noisy sound.
help me to change feedback.what should i do?

is there any problem or worng parts or circuits in this schematic?which part?and what is the correct part?
i change this schematic a little bit.
my primary winding turns is 19 and secondary is 8*2
i use a etd 39 core
target output voltage is 45*2
i change frequncy to 80 KHz