Is there a simple way to convert 12 volt to 3,9 volt.
thx for all ansers !!
Yes.
But that's a simple answer, and depends what you want to do with the 3.9 volts.
I want to cenoct a neoway m590 to the arduino uno. The Oerational Voltage is from 3.3V to 4.5V, but the recoment the recomend value is 3.9v.
You're still being a bit economical with details.
How much current?
(Your original post said 5 V, not 12 V)
The 5 Volt where an typing error. The arduino will be powered by a 12 volt battery thats why i want to power the m590 also via the battery. The Problem is tath the module can use up to 2A. here is a link to the datashett http://docs.mirifica.eu/Neoway.com/archive/M590/Neoway%20M590%20Hardware%20Design%20Manual%20V1.1.pdf.
why not use a tiny buck converter?
Something like this?: http://www.ebay.co.uk/itm/5pcs-LM2596S-DC-DC-Buck-Converter-Adjustable-Power-Supply-Step-Down-Module-UK-/141210161794?hash=item20e0c81282:g:RFgAAOxyUylTTmY2
Adjust to whatever voltage you want, 2A rated (assuming the quality is good enough - eBay can be
hit and miss, but I've used cheap LM2596 modules before without issue).