What I want from my power supply is to be able to drive a nixie clock, so more than 4 tubes.

So the key requirements are:

• DC-DC boost converter
• Vin 5 or 12 V
• Vout around 170 V
• Iout around 50 mA

Now, the idea is to build a boost converter and not a flyback one. This is because for me it is more challenging the boost type and there is no need to use a transformer. In the future maybe I will design also a flyback transformer, eventually involving voltage multiplier stages.

Some inspiration came from:

• This project here on hackaday
• This design based on MAX1771 
• A very well made project on how to build the full clock, including the power supply
• Another already available design based on MC34063
• The great design step-by-steb explained by surfncircuits

the idea is to take a lot of inspiration from these great guys, but building something new. So I will use a different IC from the ones that are commonly used in the examples online.