DC-DC Converter question

[skeeterb]

I was looking at a circuit diagram by tcmtech 555 Sine Wave Inverter 2.0, and saw how it uses 2 power inputs. The 170-340 VDC input that gets converted in the power section of his circuit and the 12-36 VDC that powers the 555s. I didn't want to necro the thread since it is nearly 2 years old. I was thinking of adding a DC-DC converter to this circuit to pull it down from the high input voltages that go to the IGBTs/Mosfets. My question is how would I go about designing a circuit that would pull it from like 170 VDC down to 12-15 VDC. If it's powered by solar panels or a wind turbine, the input power would stay pretty stable.I'm not wanting anyone to do this for me, but a little advice would be nice. Thanks for any help that you guys can give.

 

[alec_t]

My question is how would I go about designing a circuit that would pull it from like 170 VDC down to 12-15 VDC.

The peak voltage of the sinewave output would then be only 12-15V. Is that what you want?

 

[kubeek]

Do you mean to get the supply votlage for the 555? Or to get that low main output voltage?

 

[skeeterb]

I was wanting to draw off a little of the power off the 170-340 VDC INPUT voltage reducing it down to say 12-15 volts to power the 555s, NOT to change the 170-340 volts DC to the lower voltage. I also DO NOT want to draw off of the output of the circuit. Sorry if I wasn't clear on that point. The emphasis was put in to show what I meant.