LED Bulbs Polarity Sensitive

[Ron_Fran]

We are working on replacing all of our interior lighting with LEDs. We buy LED bulbs that consist of a cluster of LEDs on a base that will plug into our existing 12 volt light sockets. I had two sockets where the bulbs would not work. The instructions said nothing about polarity, but I know that LEDs are polarity sensitive so I reversed the wiring on my sockets and they now work.

I thought it was strange that the manufacturer's instructions say nothing about the polarity of the socket. Anyone else see this?

[Pblais]

I know that LEDs are polarity sensitive so I reversed the wiring on my sockets and they now work.

Just because light sockets are designed to be installed properly does not always mean they are. It's hard to expect manufacturers to list all the things that may be not done properly given the almost infinite number of ways they might be wrong.

With conventional bulbs you wouldn't notice the problem and neither would a person checking the installation of the socket if that was the type of bulb intended unless they tested it specifically. You were lucky you checked the polarity and didn't rewire the whole circuit. It never hurts to double check that things were done properly the first time.

[bstreep]

LED drivers are usually VERY polarity sensitive. The ones I use will fry within 20 seconds.

[jaga]

As bstreep says, the bare leds are usually polarity sensitive, but there seems to be a difference in how they're wired together into 'bulbs'. I've used quite a few brands of led 'bulbs' and some are polarity sensitive and some are not. I'm surprised, though, that it wasn't indicated on your packaging. All the ones I've bought stated if it was an issue, generally saying (as you found) to reverse the contacts if it doesn't work.

[Viking Sailor]

Originally Posted by jaga

I'm surprised, though, that it wasn't indicated on your packaging. All the ones I've bought stated if it was an issue, generally saying (as you found) to reverse the contacts if it doesn't work.

What's even more surprising is that the makers didn't add 4 low cost diodes to there circuit to make it handle reverse polarity.