lm2577 projects
The basic principle is converting the original DC into AC, then step this AC up to the desired value by a transformer, finally rectify it to get the necessary DC voltage.
One of the most important pros of this principle is we can use the AC with the frequency higher than the mains, upto hundreds thousand hertz, so we can use the smaller transformer, smaller filtering capacitors and inductors, thus get the smaller and lighter DC-DC converters. In the other hand, we can stabilize the output voltage easily.
Depending the power you need, or how important your project is, so you can design by yourself the simple circuit with 2 transistors and a transformer, or use a 555 timer as astable multivibrator with the power amplifier on transistors, or design a more complicated DC boost converter, or use the dedicated ICs for this purpose such as popular MC34063 from ON semiconductor, or buy the ready-made from any professional manufacturer as Delta, Deer, ... from China.
You will find out it is not as so complicated as you imagine at the beginning. Free and good document are everywhere on the internet and Google is our best friend.
Goodluck
nguyennam