this 12VDC to 5VDC power for Pi

[lilzz]

On this circuit
http://www.eleccircuit.com/wp-content/u ... lm2596.jpg

incoming 12VDC,

1) Can I substitue C1 and C2 with 1000uF because I have excess of that cap?
2)Can I subsititue H1 with 100uH?

And I will get LM2596-5.0 for 5V output.

[mahjongg]

Most often such changes are not of much influence, but make sure the inductor is suitable, not a tiny 100uF as used for decoupling, but a real power inductor. Read the device dataheet for more insight.
http://www.google.nl/url?sa=t&rct=j&q=& ... GQ&cad=rja

Most often such build your own devices are not much sense, as you can buy a suitable cigar plug adapter for less than the components will cost to build one, and suitable cigar plug adapters already have USB output ports, so you only need the USB to micro-USB cable.


Only power the PI through the micro-USB port, otherwise you bypass the electrical protection mechanisms of the PI (fuse etc).

[Burngate]

1) Can I substitue C1 and C2 with 1000uF because I have excess of that cap?
2)Can I subsititue H1 with 100uH?

Yes & Yes.

One interesting thing about these switch-mode circuits - the lower the current you're going to supply, the larger the inductor you need, which is just the opposite of what capacitance you need.
So increasing both gives you more headroom in both directions