How to get rid of Interference on Car USB Adapter
October 23, 2010 11:54 PM Subscribe
How can I get rid of the audio interference caused when I use a 12v charger with an mp3 player in my car?
posted by Popcorn to Technology (10 answers total)
I've got a late 80's full size ford truck that has a 3.5mm aux-in that I plug my mp3 player into. I have a 12v cigarette lighter to USB adapter that I use to charge the device.
I saw this thread, but it's doesn't answer all my questions.
When the device is charging, there is a high pitched hum that tracks with the engine rpms. So, it seems like some interference from the alternator. When the engine is off it charges fine and there is no interference.
So, my question is, which of the following would be the best option.
Are these Pyramid-NSXX items the right thing for the job?
This one in particular because of the high amperage.
Where would I install this? Can it go under the hood or do I need to get up in the dashboard?
This thing below seems to get rid of the noise after the mp3 player. Seems like a silly way to go about it. Do these things actually work compared to something that actually conditions the 12v power?
Then there is this one that uses RCA cables, but it has those two additional brown wires. What are those for?
Also, can anybody explain or give me a link to what is going on here? I'd like to know what, specifically , is causing the noise? What currents are actually going through the wire? Is it 12v DC plus some other AC current on top of it? Is that even possible? Also, what kind of components are in the devices linked above? Capacitors?
Finally, as a bonus question, does anybody know where one can find PDF versions of those Chilton repair manuals for ford trucks? I've searched high and low to no avail.
Thanks in advance!