I have been trying to find a non-isolated buck converter (12 Vdc input to 5 Vdc, 2A output) with the CE certification. This is similar to a USB charger that fits in the cigarette lighter of a car but with wires or screw terminals for input/output instead of the USB and cigarette connectors.

I know these converters are very popular and are used in cars/boats, solar, lots of battery powered devices. I don't think it's a coincidence that none of them are CE certified. How are these imported and sold in Europe without the CE marking? Is there an exception for very low DC voltage devices?

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    \$\begingroup\$ Components aren't usually certified, only "products". \$\endgroup\$ – pjc50 Dec 2 '16 at 17:38
  • \$\begingroup\$ I've looked at components and products. Many of these converters are sold straight to consumers so would be considered a product and have to meet the CE requirements (I think). You can find them on amazon.com. \$\endgroup\$ – Joe Mac Dec 2 '16 at 17:47
  • \$\begingroup\$ "you can find them on amazon" definitely doesn't make them any less components that aren't end-user equipment. Also, CE is a European self-certification – you might be on the wrong amazon site if you're on amazon.com. \$\endgroup\$ – Marcus Müller Dec 2 '16 at 18:33
  • \$\begingroup\$ I went to amazon.co.uk. You may be right that they aren't considered "end-user equipment." If so, then maybe that's my answer. Then I am surprised that an "end-user equipment" version doesn't exist. \$\endgroup\$ – Joe Mac Dec 2 '16 at 19:24

This appears to be a legal question so: I am not a lawyer and this is not legal advice. Now that's out of the way, here is what the U.K. regulations state:

Requirements for placing on the market

  1. No person shall place on the market apparatus unless either the following requirements, or the corresponding requirements of the EMC Directive as implemented under the law of another state in the Community, are met—

    (a)the apparatus is compliant with the essential requirements; (b)compliance with the essential requirements has been demonstrated in accordance with regulation 18; (c)the technical documentation including any statement issued by a notified body under regulation 20 has been prepared and is available to the enforcement authority on request; (d)the CE marking has been properly affixed by the manufacturer or his authorised representative in accordance with regulation 21; (e)an EC declaration of conformity has been issued in accordance with the requirements of regulation 22; (f)each apparatus is identified in terms of type, batch, serial number or any information allowing for identification of the apparatus; (g)each apparatus is accompanied by the name and address of the manufacturer and if he is not established in the Community, the name and address of the responsible person; (h)the manufacturer has provided information on any specific precautions that must be taken when the apparatus is assembled, installed, maintained or used in order to ensure that when put into service the apparatus complies with the essential requirements; (i)apparatus for which compliance with the essential requirements is not ensured in residential areas is accompanied by a clear indication of this restriction of use and where appropriate this indication is also on the packaging; and (j)the information required to enable the apparatus to be used in accordance with its intended purpose is contained in the instructions accompanying the apparatus.

This is from The Electromagnetic Compatibility Regulations 2006. Look at (d). It specifically prohibits you to put a device on the market, if you have not affixed the CE marking to the device, or to the packaging, if there is not enough space, as stated in 21.

So it appears that these manufacturers do not comply with the regulation. On the other hand, they are probably not a priority for the regulators.

The only exceptions are:

  1. The requirements in regulation 15 and 16 shall not apply to— (a)the placing on the market of apparatus before 20th July 2009; and (b)the putting into service of apparatus placed on the market before 20th July 2009, where, on or before 19th July 2007, a declaration of conformity in respect of such apparatus has been issued by the manufacturer or his authorised representative pursuant to Article 10.1 or 10.2 of Directive 89/336/EEC as implemented in the United Kingdom to enable it to be placed on the market or put into service, or both.

And electromagnetically benign equipment:

  1. These Regulations do not apply to equipment the inherent qualities of which are such that—

    (a)it is incapable of generating or contributing to electromagnetic emissions which exceed a level allowing radio and telecommunication equipment and other equipment to operate as intended; and (b)it will operate without unacceptable degradation in the presence of electromagnetic disturbance normally consequent upon its intended use.

  • \$\begingroup\$ I think a device with an oscillator above 9 kHz has to be tested for RF emissions. Most (maybe all) buck converters have a switching frequency above 20 kHz so you can't hear it. So, I think 8(a) does not apply. I don't think 8(b) applies either. The only way to know with a device like a power converter would be to go through testing. \$\endgroup\$ – Joe Mac Dec 2 '16 at 18:01

This answer was given before the question was changed to include wire terminals and that makes a big difference as far as I'm concerned.

Ask yourself what CE directives a device like this needs to be compliant with and, when you decide that the EMC directive is one of them, ask yourself how will you prevent EMC non-compliances when there are only wires (that make nice antennas) for input and output? After all, a switching regulator does everything it can to make nice square edges of voltage and current in order to maximize efficiency and minimize heat lost (and therefore cost).

I'm not saying that there isn't one that may be found but, it'll probably cost significantly more than the cheapo ones from China.

Another possible thing to consider is that a buck converter with input and output leads is probably regarded as a "component" or sub-system for installation into something else and, just as the switching regulator chip isn't required to be compliant, maybe the products you refer to are also viewed the same way.

  • \$\begingroup\$ There are lots of isolated DC/DC converters that manage to get the CE marking and sell for about $50. So I'm guessing someone could make a non-isolated DC/DC converter and get it CE certified, and sell it for about the same cost. The problem is there aren't any, even expensive ones. So I don't think the problem is the CE requirements. I think there's another reason, like an exception. \$\endgroup\$ – Joe Mac Dec 2 '16 at 17:26
  • \$\begingroup\$ Please provide a link to one of the CE marked DC to DC converters with wired input and output and I'll take a look to see if something triggers a thought process. Any of the above that requires or produces a voltage higher than the low voltage directive WILL (or should) require a CE mark. \$\endgroup\$ – Andy aka Dec 2 '16 at 17:31
  • \$\begingroup\$ Here and here are two found on Digikey. If I understand correctly, the low voltage directive applies to DC voltages above 75 volts. This is below 75 volts so are these buck converters exempt? \$\endgroup\$ – Joe Mac Dec 2 '16 at 17:34
  • \$\begingroup\$ Neither of them are shipped with wires on their inputs and output terminals. This means that passing EMC regulations is profoundly more easier and no-doubt (from such reputable suppliers) the data sheet will go at some length to explain what the "incorporator" must do when making connections (in order to remain compliant). You are talking about modules with input and output wires according to you question so please don't muddle this up. \$\endgroup\$ – Andy aka Dec 2 '16 at 17:38
  • \$\begingroup\$ From my understanding of CE, you're supposed to test the equipment in the most common configurations (i.e. with wires). So I don't think using screw terminals is a work around the CE requirements. If it is a work around, couldn't a manufacturer use screw terminals with a non-isolated DC/DC converter? \$\endgroup\$ – Joe Mac Dec 2 '16 at 17:52

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