It looks fine.

Are you driving the gate with a Raspberry Pi?

 

It looks fine.

Are you driving the gate with a Raspberry Pi?

yes this is my project to control the boost and the buck boost by the raspberrypi i did that for the first converter(BOOST) .
i should get -12V in the source right?due to the LTspice i get just -5.6V you saw the pictures that i sent?

 

I see about -10V peak on cathode of the diode in the scope screen shot, so I would expect -9V or a little more negative across the capacitor.

 

yes i get on the output -9V in Rmax=125ohm ,and if i change duty cycle i would get -12V but my problem that if i change the load(resistor) to Rmin=25ohm i get 5V or 6V (I HAVE A BIG DIFFERENCE) i just want a 3V difference

 

Adding regulation will help but so will removing the resistor in series with the inductor and using the lowest resistance inductor you can get your hands on.

 

i will try to get inductor with low resistance (to order) ,
I'll probably have to wait
, because i dont have right now a different inductors

 

Good, I guess.

yes i get on the output -9V in Rmax=125ohm ,and if i change duty cycle i would get -12V but my problem that if i change the load(resistor) to Rmin=25ohm i get 5V or 6V (I HAVE A BIG DIFFERENCE) i just want a 3V difference

I am glad to see that you have your specifications in writing. You can try to model the inductance you are about to order (including the equivalent series resistance) to see how much performance is improved by the new inductor, before you order it.

 

I hope the coil is the problem there is in BUCK BOOST, until what I ordered arrives, I want to share with you a problem I discovered in my BOOST converter, i press 12V and i get on the output 12V like i want, when I change the load(125ohm) at the output and reach a resistance of 50ohm the voltage of the power supply goes down and its input current(of the power supply) rises to 2.6A, In the converter the output voltagedrops to zero, i calculate the input
current :
Iin = Iout * (Vout / Vin)=(12/50)*(12/3)=0.96A - I see in the power supply that the limit current is 3A,So what is the problem?