USB charging, Thinking about adding 5volts Options

[worn]

I got a bunch of USB sockets and voltage regulator ICs that will trim 12v to 5v, and thought it would be nice to wire in for charging phones etc. someone suggested that the ICs would fry due to transients. So I am wondering about wiring zener diodes as shunts across the feed and wanted to know what you thought. I am especially interested in voltage and wattage for the zener and perhaps resistance to limit current. Thanks!

[stugray]

The 7805 should work fine in this car as long as you dont have a CD (MSD) ignition in it.

I plug my arduino datalogger directly into the system 12VDC and I DO have a MSD.

MSD makes a transient surge suppressor for this very reason, but it is really for more modern cars that have a LOT of electronics in them:

http://www.msdignition.com/Products/Access...r,_26_Kufd.aspx

But it is really just about the same as some of the ultracaps you can find in the car stereo dept. at walmart.

[worn]

The 7805 should work fine in this car as long as you dont have a CD (MSD) ignition in it.

I plug my arduino datalogger directly into the system 12VDC and I DO have a MSD.

MSD makes a transient surge suppressor for this very reason, but it is really for more modern cars that have a LOT of electronics in them:

http://www.msdignition.com/Products/Access...r,_26_Kufd.aspx

But it is really just about the same as some of the ultracaps you can find in the car stereo dept. at walmart.

Thanks Stu. I figured you would address the transient question. Do the ultra caps do much? Other than make for bling? This project is for the stock 3.2 conversion. I may eventually run MSD on the 4.