Re: Replacing the 7805 on the Raduino so something that does not get so hot

Ashhar Farhan

The switching mode regulators are invariably noisy. that's the main reason to avoid them.

MVS Sarma had a suggestion, we can remove the backlight LED out of the regulator and directly feed it with a resistor from 12v. that should significantly bring down the power consumption from the 7805

- f

On Sat, Mar 11, 2017 at 9:59 PM, <motdog@...> wrote:


I would try a resistor in series to the 7805, I have used really small and cheap ones from Mouser.  Usually 1 watt, they are like 0.4" long and $0.10.

Up the resistance until the voltage at the 7805 meets requirements.  Probably 8V will be enough.  Or put a 7809 in front?

The other thing, put a TO220 big regulator on it.  Also, if you have an LCD with back light, connect it to 12V thru a bigger resistor to take

the current out of the small regulator.  That is usually 50 ma or so.  You could maybe add a second regulator just for the LED back light, it is current you are setting, not voltage.

The switching version my not be good in a radio!  May have some nice birdies!

I never use the regulator built into Nano Arduinos, it is so cheap to put a TO-220 one external?

I have blow up the ones on the Nanos,  Nano is my favorite, I have used several of them in projects. eBay for a few bucks.


Mike, WA6ISP

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