startup circuit for microcontroller based converter

[--BawA--]

Hello everyone, I am designing a Microcontroller based forward converter of following ratings
Input 125VAC to 265VAC
output 12VDC
Power 32 watts
auxilary winding voltage 16V

During startup , Microcontroller and mosfet driver IC will take power from the mains through bootstrap startup circuit , and in steady state , they'll take power from auxilary winding from the Transformer,

below is the startup circuit



Intended voltage for MCU is 5V and for mosfet driver 12V to 15V will be ok
This startup circuit will give output approx 15V , now my question is "Can i connect a LM7805 at the output(emmiter) of this startup circuit to powerup the microcontroller,
or is there any other way to get 5v and 15v from the startup circuit?

 

[vicky001.iith]

One more way is using zener diode to step voltage from 12V to 5V. As shown in this figure

But it can have some noisy output(A surge in voltage sometimes) which would not be good for Microcontroller.
So, It is better to use voltage regulator like LM78series.Just take care of i/p & o/p capacitors for LM ic.