I am building an LED light that plugs into the audio jack of a mobile device and is powered by the 3.5mm audio plug of the smartphone. The LED works at very low tension and with audio frequencies below 2kHz.

Does such a device require a CE and FCC mark if I want to market it in the US and Europe?

I read a little about FCC 47 CFR 15 and I am rather confused.

  • 1
    \$\begingroup\$ What does it do? How does it work? What is the goal you're trying to accomplisch? It might very well depend on the implementation, so a circuit diagram or picture would be helpful. \$\endgroup\$
    – jippie
    Feb 24, 2013 at 17:05
  • \$\begingroup\$ Protected from "me too" answers, though there are no answers. :) \$\endgroup\$
    – Kaz
    Feb 24, 2013 at 19:13
  • \$\begingroup\$ @jippie [link] (i50.tinypic.com/1rom02.jpg). The light plugs into a smartphone, interfaces with an app and flashes for incoming notifications such as calls and emails. Under the cap there are two LEDs soldered to the jack and is powered by the audio signal from the phone. \$\endgroup\$
    – user19384
    Feb 24, 2013 at 20:13

1 Answer 1


I can only speak about CE marking. It's no big-deal on this simple product to CE mark (and if it is too small then the packaging needs to be CE marked). It's electrical and my understanding is that it will need CE marking.

Don't despair, for something like this it isn't a minefield of legislation. You need to look-up the list of directives. Here's one I prepared earlier: -

enter image description here

Then you decide which ones may apply - ignore the rest but be concientious and not cynical about this. Liklihood is that several may apply and you prepare a document that justifies why they don't apply OR, if some do you justify why only certain sections of a directive apply. This is called the self certification route and there's a realm of good info here.

This covers you but like i say, don't be cynical about stuff - low voltage directive applies to anything where the voltage is above a certain level and although you are powered from a cell-phone, give a little more than lip-service to why you won't produce voltages that mean you have to comply.

EMC directive might be applicable and maybe you have to throw in some sentences that justifies you won't be interfering with the radio signal in any way - difficult to prove but best have answers documented.

You'll have several days (14 I think) if someone challenges your "right" to CE mark your product so it's best to have the info on-hand in the form of a "technical file".


Not the answer you're looking for? Browse other questions tagged or ask your own question.