I am making a commercial LED lamp. I am using a non-isolated circuit. I am using buck converter. Is it safe? Can I use a buck converter after the bridge rectifier?

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    \$\begingroup\$ I've edited your question to make it read more naturally. Also, it seems you had two mostly unrelated questions, and I removed the second. Please ask it separately. \$\endgroup\$
    – Phil Frost
    Commented Jul 26, 2014 at 11:05

1 Answer 1



The simple answer is no. It's not safe.

That is, it's no more or less safe than any lamp which runs off mains and is not isolated. If you pay close attention to design and construction, it can be OK.

As for longevity, that depends on the design, the parts used, and the construction techniques. So it's not as if I can even try to answer that part of the question. However, since you missed the first part, I'm not optimistic about this part.

As for the last, a mains-powered LED driver is, or ought to be, CC by its nature, and by its nature simply doesn't care about PFC.

And let me be blunt. Please, Arshid, stay out of the LED lamp business, at least until you have learned a LOT more about electronics. Right now your level of ignorance, when applied to this forum, is obvious. When applied to the idea of designing, manufacturing and selling a commercial product, your level of ignorance is frightening.

  • \$\begingroup\$ See this excellent answer which advocates non-isolated, though with a profit motive - designingwithleds.com/…. I'm also thinking about making a custom LED driver because I can't find one that runs on 110V and has a builtin remote dimmer. The closest I found is the EyeNut, eyenut.co.uk/products/driversandadaptors.html#topnav, but it's for 220V. I will power a 2' x 2' panel mounted on the ceiling, which is already isolated in a plastic shell and is unlikely to be touched. \$\endgroup\$
    – Yale Zhang
    Commented Jan 23, 2016 at 23:29

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