I need HELP! Step-up (Boost) DC-DC Converter

[needed]

Hey everyone!

I have a project and need some help from you!
The project is to design and simulate a circuit for a Step-up (Boost) DC-DC Converter, 6v-12v or 9v-12.

The most important thing is to get a working circuit for that converter!

Awaiting your help,
Many thanks in advance.

 

[Harvey]

You'll find reference ciruits in the application notes from most manufcaturers of power supply semiconductors.