SparkFun Forums

[kiwi_mat]

I have a new usb-host sheid (spark-fun one of course)..

I have it atop a arduino pro board, which is being fed 12v @ 1amp so the vin to the host sheild is that..

When I plug-in my google nexus one android phone, the 5V regulator gets very hot, far too hot to touch. I know the regulator can supply 800ma, so I suspect its maxing out on that, the nexus-one may be able to suck as much as 1amp as that is what its own wall charger can supply..

So? is there a problem, or should I not worry?

Thanks for any help..

[Inopia]

I had the same issue plugging in my ZTE Blade. I left my Arduino spewing logcat messages out over serial for about eight hours and when I came back everything was still working fine, so don't worry.

[itikhonov]

LM1117 regulator has internal current limiting and thermal protection but you are asking trouble anyway. If you don't scared of doing some math read LM1117 datasheet section 5.0 and calculate wherever you have problems or not.

Or you can measure temperature of regulator and if it's beyond or near 125C, you have a problem. Or you can get LM1117 in a fat TO-220 package and solder it upright instead of this tiny sot223. With heavy bolt screwed to it's heatsink.

[kiwi_mat]

Interesting, I know its hot enough that it burns fingers..

I will see if there is a temp reader here at work.